List of genetics-related topics
Genetics , a discipline of biology, is the science of genes, heredity, and variation in living organisms....

(from Ancient Greek
Ancient Greek
Ancient Greek is the stage of the Greek language in the periods spanning the times c. 9th–6th centuries BC, , c. 5th–4th centuries BC , and the c. 3rd century BC – 6th century AD of ancient Greece and the ancient world; being predated in the 2nd millennium BC by Mycenaean Greek...

  , “genite” and that from , “origin”), a discipline of biology
Biology is a natural science concerned with the study of life and living organisms, including their structure, function, growth, origin, evolution, distribution, and taxonomy. Biology is a vast subject containing many subdivisions, topics, and disciplines...

, is the science
Science is a systematic enterprise that builds and organizes knowledge in the form of testable explanations and predictions about the universe...

 of heredity
Heredity is the passing of traits to offspring . This is the process by which an offspring cell or organism acquires or becomes predisposed to the characteristics of its parent cell or organism. Through heredity, variations exhibited by individuals can accumulate and cause some species to evolve...

 and variation
Genetic variation
Genetic variation, variation in alleles of genes, occurs both within and among populations. Genetic variation is important because it provides the “raw material” for natural selection. Genetic variation is brought about by mutation, a change in a chemical structure of a gene. Polyploidy is an...

 in living organism
In biology, an organism is any contiguous living system . In at least some form, all organisms are capable of response to stimuli, reproduction, growth and development, and maintenance of homoeostasis as a stable whole.An organism may either be unicellular or, as in the case of humans, comprise...


Articles (arranged alphabetically) related to genetics
Genetics , a discipline of biology, is the science of genes, heredity, and variation in living organisms....



  • Acentric chromosome
  • Achondroplasia
    Achondroplasia dwarfism occurs as a sporadic mutation in approximately 85% of cases or may be inherited in an autosomal dominant genetic disorder that is a common cause of dwarfism...

  • Active site
    Active site
    In biology the active site is part of an enzyme where substrates bind and undergo a chemical reaction. The majority of enzymes are proteins but RNA enzymes called ribozymes also exist. The active site of an enzyme is usually found in a cleft or pocket that is lined by amino acid residues that...

  • Adam's Curse
    Adam's Curse
    Adam's Curse: A Future Without Men is a 2003 book by Oxford University human genetics professor Bryan Sykes expounding his hypothesis that with the declining sperm count in men and the continual atrophy of the Y chromosome, within 5,000 generations the male of the...

  • Adaptation
  • Adenine
    Adenine is a nucleobase with a variety of roles in biochemistry including cellular respiration, in the form of both the energy-rich adenosine triphosphate and the cofactors nicotinamide adenine dinucleotide and flavin adenine dinucleotide , and protein synthesis, as a chemical component of DNA...

  • Adenosine
  • Adenovirus
  • Adenosine diphosphate
    Adenosine diphosphate
    Adenosine diphosphate, abbreviated ADP, is a nucleoside diphosphate. It is an ester of pyrophosphoric acid with the nucleoside adenosine. ADP consists of the pyrophosphate group, the pentose sugar ribose, and the nucleobase adenine....

  • Ala
    Alpha-linolenic acid
    α-Linolenic acid is an organic compound found in many common vegetable oils. In terms of its structure, it is named all-cis-9,12,15-octadecatrienoic acid. In physiological literature, it is given the name 18:3 ....

  • Alagille syndrome
    Alagille syndrome
    Alagille syndrome is a genetic disorder that affects the liver, heart, kidney, and other systems of the body. Problems associated with the disorder generally become evident in infancy or early childhood...

  • Albino
  • Alcoholism
    Alcoholism is a broad term for problems with alcohol, and is generally used to mean compulsive and uncontrolled consumption of alcoholic beverages, usually to the detriment of the drinker's health, personal relationships, and social standing...

  • Alkylating agent
  • Allele
    An allele is one of two or more forms of a gene or a genetic locus . "Allel" is an abbreviation of allelomorph. Sometimes, different alleles can result in different observable phenotypic traits, such as different pigmentation...

  • Allele frequency
    Allele frequency
    Allele frequency or Gene frequency is the proportion of all copies of a gene that is made up of a particular gene variant . In other words, it is the number of copies of a particular allele divided by the number of copies of all alleles at the genetic place in a population. It can be expressed for...

  • Alleles
  • Allopolyploid
  • Allosteric protein
  • Allozyme
    Variant forms of an enzyme that are coded by different alleles at the same locus are called allozymes. These are opposed to isozymes, which are enzymes that perform the same function, but which are coded by genes located at different loci....

  • Alternative splicing
    Alternative splicing
    Alternative splicing is a process by which the exons of the RNA produced by transcription of a gene are reconnected in multiple ways during RNA splicing...

  • Altruism
    Altruism is a concern for the welfare of others. It is a traditional virtue in many cultures, and a core aspect of various religious traditions, though the concept of 'others' toward whom concern should be directed can vary among cultures and religions. Altruism is the opposite of...

  • Alu family
  • Alzheimer's disease
    Alzheimer's disease
    Alzheimer's disease also known in medical literature as Alzheimer disease is the most common form of dementia. There is no cure for the disease, which worsens as it progresses, and eventually leads to death...

  • Amber codon
  • Ames test
    Ames test
    The Ames test is a biological assay to assess the mutagenic potential of chemical compounds. A positive test indicates that the chemical is mutagenic and therefore may act as a carcinogen, since cancer is often linked to mutation. However, a number of false-positives and false-negatives are known...

  • Amino acid
    Amino acid
    Amino acids are molecules containing an amine group, a carboxylic acid group and a side-chain that varies between different amino acids. The key elements of an amino acid are carbon, hydrogen, oxygen, and nitrogen...

  • Amino acid sequence
  • Amino acids
  • Amniocentesis
    Amniocentesis is a medical procedure used in prenatal diagnosis of chromosomal abnormalities and fetal infections, in which a small amount of amniotic fluid, which contains fetal tissues, is sampled from the amnion or amniotic sac surrounding a developing fetus, and the fetal DNA is examined for...

  • Amorph
    Amorph may refer to:*Muller's morphs*Amorphous*Carbosilicate Amorphs, a fictional species...

  • AMP
    Adenosine monophosphate
    Adenosine monophosphate , also known as 5'-adenylic acid, is a nucleotide that is used as a monomer in RNA. It is an ester of phosphoric acid and the nucleoside adenosine. AMP consists of a phosphate group, the sugar ribose, and the nucleobase adenine...

  • Amphidiploid
  • Amplification
    Polymerase chain reaction
    The polymerase chain reaction is a scientific technique in molecular biology to amplify a single or a few copies of a piece of DNA across several orders of magnitude, generating thousands to millions of copies of a particular DNA sequence....

  • Anagenesis
    Anagenesis, also known as "phyletic change," is the evolution of species involving an entire population rather than a branching event, as in cladogenesis. When enough mutations have occurred and become stable in a population so that it is significantly differentiated from an ancestral population,...

  • Anaphase
    Anaphase, from the ancient Greek ἀνά and φάσις , is the stage of mitosis or meiosis when chromosomes move to opposite poles of the cell....

  • Aneuploid
  • Aneuploid cell
  • Aneuploidy
    Aneuploidy is an abnormal number of chromosomes, and is a type of chromosome abnormality. An extra or missing chromosome is a common cause of genetic disorders . Some cancer cells also have abnormal numbers of chromosomes. Aneuploidy occurs during cell division when the chromosomes do not separate...

  • Angelman syndrome
    Angelman syndrome
    Angelman syndrome is a neuro-genetic disorder characterized by intellectual and developmental delay, sleep disturbance, seizures, jerky movements , frequent laughter or smiling, and usually a happy demeanor....

  • Angiosperm
  • Animal model
    Animal model
    An animal model is a living, non-human animal used during the research and investigation of human disease, for the purpose of better understanding the disease without the added risk of causing harm to an actual human being during the process...

  • Annealing
  • Annotation
    An annotation is a note that is made while reading any form of text. This may be as simple as underlining or highlighting passages.Annotated bibliographies give descriptions about how each source is useful to an author in constructing a paper or argument...

  • Antibody
    An antibody, also known as an immunoglobulin, is a large Y-shaped protein used by the immune system to identify and neutralize foreign objects such as bacteria and viruses. The antibody recognizes a unique part of the foreign target, termed an antigen...

  • Anticipation
    Anticipation (genetics)
    In genetics, anticipation is a phenomenon whereby the symptoms of a genetic disorder become apparent at an earlier age as it is passed on to the next generation. In most cases, an increase of severity of symptoms is also noted. Anticipation is common in trinucleotide repeat disorders such as...

  • Anticoding strand
  • Anticodon
  • Antigen
    An antigen is a foreign molecule that, when introduced into the body, triggers the production of an antibody by the immune system. The immune system will then kill or neutralize the antigen that is recognized as a foreign and potentially harmful invader. These invaders can be molecules such as...

  • Antimorph
  • Antiparallel
    Antiparallel (biochemistry)
    In biochemistry, two molecules are antiparallel if they run side-by-side in opposite directions or when both strands are complimentary to each other....

  • Antisense
  • Antisense RNA
  • Antisense strand
  • Antisense therapy
    Antisense therapy
    Antisense therapy is a form of treatment for genetic disorders or infections.When the genetic sequence of a particular gene is known to be causative of a particular disease, it is possible to synthesize a strand of nuc acid that will bind to the messenger RNA produced by that gene and inactivate...

  • AP endonuclease
  • AP site
    AP site
    In biochemistry and molecular genetics, an AP site , also known as an abasic site, is a location in DNA that has neither a purine nor a pyrimidine base, either spontaneously or due to DNA damage...

  • Apert syndrome
    Apert syndrome
    Apert syndrome is a form of acrocephalosyndactyly, a congenital disorder characterized by malformations of the skull, face, hands and feet. It is classified as a branchial arch syndrome, affecting the first branchial arch, the precursor of the maxilla and mandible...

  • Apoptosis
    Apoptosis is the process of programmed cell death that may occur in multicellular organisms. Biochemical events lead to characteristic cell changes and death. These changes include blebbing, cell shrinkage, nuclear fragmentation, chromatin condensation, and chromosomal DNA fragmentation...

  • Applied genetics
  • Arg
    Arginine is an α-amino acid. The L-form is one of the 20 most common natural amino acids. At the level of molecular genetics, in the structure of the messenger ribonucleic acid mRNA, CGU, CGC, CGA, CGG, AGA, and AGG, are the triplets of nucleotide bases or codons that codify for arginine during...

  • Arrayed library
    Tissue microarray
    Tissue microarrays consist of paraffin blocks in which up to 1000 separate tissue cores are assembled in array fashion to allow multiplex histological analysis.-History:...

  • Ascospore
    An ascospore is a spore contained in an ascus or that was produced inside an ascus. This kind of spore is specific to fungi classified as ascomycetes ....

  • Ascus
    An ascus is the sexual spore-bearing cell produced in ascomycete fungi. On average, asci normally contain eight ascospores, produced by a meiotic cell division followed, in most species, by a mitotic cell division. However, asci in some genera or species can number one , two, four, or multiples...

  • Asexual spore
  • Asn
    ASN may refer to:Organisations:* ASN Bank in the Netherlands* American Society of Nephrology* American Society for Neurochemistry* American Society of Neuroimaging* American Society for Nutrition...

  • Asp
    Aspartic acid
    Aspartic acid is an α-amino acid with the chemical formula HOOCCHCH2COOH. The carboxylate anion, salt, or ester of aspartic acid is known as aspartate. The L-isomer of aspartate is one of the 20 proteinogenic amino acids, i.e., the building blocks of proteins...

  • Assembly
  • Assortative mating
    Assortative mating
    Assortative mating , and the related concept Disassortative mating, is the phenomenon where a sexually reproducing organism chooses to mate with individuals that are similar or dissimilar to itself in some specific manner...

  • Atavism
    Atavism is the tendency to revert to ancestral type. In biology, an atavism is an evolutionary throwback, such as traits reappearing which had disappeared generations before. Atavisms can occur in several ways...

  • ATP
    Adenosine triphosphate
    Adenosine-5'-triphosphate is a multifunctional nucleoside triphosphate used in cells as a coenzyme. It is often called the "molecular unit of currency" of intracellular energy transfer. ATP transports chemical energy within cells for metabolism...

  • Attenuator
    Attenuator (genetics)
    Attenuation is a regulatory feature found throughout Archaea and Bacteria causing premature termination of transcription. Attenuators are 5'-cis acting regulatory regions which fold into one of two alternative RNA structures which determine the success of transcription...

  • Autogamy
  • Autopolyploid
  • Autoradiograph
    An autoradiograph is an image on an x-ray film or nuclear emulsion produced by the pattern of decay emissions from a distribution of a radioactive substance...

  • Autoradiography
  • Autosomal dominant
  • Autosome
    An autosome is a chromosome that is not a sex chromosome, or allosome; that is to say, there is an equal number of copies of the chromosome in males and females. For example, in humans, there are 22 pairs of autosomes. In addition to autosomes, there are sex chromosomes, to be specific: X and Y...

  • Autotroph
    An autotroph, or producer, is an organism that produces complex organic compounds from simple inorganic molecules using energy from light or inorganic chemical reactions . They are the producers in a food chain, such as plants on land or algae in water...

  • Auxotroph
  • Auxotrophic mutant
  • Axoneme
    Numerous eukaryotic cells carry whip-like appendages whose inner core consists of a cytoskeletal structure called the axoneme....


  • B form DNA
  • Bacillus
    Bacillus is a genus of Gram-positive, rod-shaped bacteria and a member of the division Firmicutes. Bacillus species can be obligate aerobes or facultative anaerobes, and test positive for the enzyme catalase. Ubiquitous in nature, Bacillus includes both free-living and pathogenic species...

  • Back mutation
  • Backcross
  • Bacteria
    Bacteria are a large domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria have a wide range of shapes, ranging from spheres to rods and spirals...

  • Bacterial conjugation
    Bacterial conjugation
    Bacterial conjugation is the transfer of genetic material between bacterial cells by direct cell-to-cell contact or by a bridge-like connection between two cells...

  • Bacterial lawn
    Bacterial lawn
    Bacterial lawn is a term used by microbiologists to describe the appearance of bacterial colonies when all the individual colonies on a petri-dish agar plate merge together to form a field or mat of bacteria...

  • Bacteriophage
    A bacteriophage is any one of a number of viruses that infect bacteria. They do this by injecting genetic material, which they carry enclosed in an outer protein capsid...

  • Balbiani ring
  • Barr body
    Barr body
    A Barr body is the inactive X chromosome in a female somatic cell, rendered inactive in a process called lyonization, in those species in which sex is determined by the presence of the Y or W chromosome rather than the diploidy of the X or Z...

  • Basal body
    Basal body
    A basal body is an organelle formed from a centriole, and a short cylindrical array of microtubules. It is found at the base of a eukaryotic undulipodium and serves as a nucleation site for the growth of the axoneme microtubules...

  • Base
    Nucleobases are a group of nitrogen-based molecules that are required to form nucleotides, the basic building blocks of DNA and RNA. Nucleobases provide the molecular structure necessary for the hydrogen bonding of complementary DNA and RNA strands, and are key components in the formation of stable...

  • Base analogue
  • Base pair
    Base pair
    In molecular biology and genetics, the linking between two nitrogenous bases on opposite complementary DNA or certain types of RNA strands that are connected via hydrogen bonds is called a base pair...

  • Base pairs
  • Base sequence
  • Batesian mimicry
    Batesian mimicry
    Batesian mimicry is a form of mimicry typified by a situation where a harmless species has evolved to imitate the warning signals of a harmful species directed at a common predator...

  • Bayesian analysis
  • Bead theory
    Bead theory
    The bead theory is a disproved hypothesis that genes are arranged on the chromosome like beads on a necklace. According to this theory, the existence of a gene as a unit of inheritance is recognized through its mutant alleles. Seymour Benzer showed in the 1950s that the bead theory was not correct....

  • Behavioral genetics
  • Behavioural genetics
    Behavioural genetics
    Quantitative human behavioural genetics is a specialisation in the biological field of behaviour genetics that studies the role of genetics in human behaviour employing quantitative-genetic methods. The field is an overlap of quantitative genetics and psychology...

  • Beta-galactosidase
    β-galactosidase, also called beta-gal or β-gal, is a hydrolase enzyme that catalyzes the hydrolysis of β-galactosides into monosaccharides. Substrates of different β-galactosidases include ganglioside GM1, lactosylceramides, lactose, and various glycoproteins...

  • Bimodal distribution
    Bimodal distribution
    In statistics, a bimodal distribution is a continuous probability distribution with two different modes. These appear as distinct peaks in the probability density function, as shown in Figure 1....

  • Binary fission
  • Binomial expansion
  • Binomial theorem
    Binomial theorem
    In elementary algebra, the binomial theorem describes the algebraic expansion of powers of a binomial. According to the theorem, it is possible to expand the power n into a sum involving terms of the form axbyc, where the exponents b and c are nonnegative integers with , and the coefficient a of...

  • Biochemical genetics
  • Bioinformatics
    Bioinformatics is the application of computer science and information technology to the field of biology and medicine. Bioinformatics deals with algorithms, databases and information systems, web technologies, artificial intelligence and soft computing, information and computation theory, software...

  • Biolistic
  • Bioremediation
    Bioremediation is the use of microorganism metabolism to remove pollutants. Technologies can be generally classified as in situ or ex situ. In situ bioremediation involves treating the contaminated material at the site, while ex situ involves the removal of the contaminated material to be treated...

  • Biotechnology
    Biotechnology is a field of applied biology that involves the use of living organisms and bioprocesses in engineering, technology, medicine and other fields requiring bioproducts. Biotechnology also utilizes these products for manufacturing purpose...

  • Biparental zygote
  • Birth defect
  • Bivalent (genetics)
    Bivalent (Genetics)
    A bivalent, sometimes referred to as a tetrad, is a pair of associated homologous chromosomes held together by a complex after chromosome replication....

    In bioinformatics, Basic Local Alignment Search Tool, or BLAST, is an algorithm for comparing primary biological sequence information, such as the amino-acid sequences of different proteins or the nucleotides of DNA sequences...

  • Blastoderm
    -In amniotes:A blastoderm is the layer of cells formed at one pole of macrolecithal eggs such as the yolky egg of birds. The yolk prevents the division from taking place through the egg, resulting in meroblastic cleavage during the many cleavage divisions...

  • Blastomere
    A blastomere is a type of cell produced by division of the egg after fertilization.- References :* "Blastomere." Stedman's Medical Dictionary, 27th ed. . ISBN 0-683-40007-X...

  • Blastopore
    A blastopore is an opening into the archenteron during the embryonic stages of an organism. The distinction between protostomes and deuterostomes is based on the direction in which the mouth develops in relation to the blastopore...

  • Blastula
    The blastula is a hollow sphere of cells formed during an early stage of embryonic development in animals . The blastula is created when the zygote undergoes the cell division process known as cleavage. The blastula is preceded by the morula and is followed by the gastrula in the developmental...

  • Blending inheritance
    Blending inheritance
    Many biologists and other academics held to the idea of blending inheritance during the 19th century, prior to the discovery of genetics. Blending inheritance was merely a widespread hypothetical model, rather than a formalized scientific theory , in...

  • Blunt-end ligation
  • Bookmarking
    In genetics and epigenetics, bookmarking is a biological phenomenon believed to function as an epigenetic mechanism for transmitting cellular memory of the pattern of gene expression in a cell, throughout mitosis, to its daughter cells...

  • Bottleneck
  • Brachydactyly
    Brachydactyly , is a medical term which literally means "shortness of the fingers and toes" . The shortness is relative to the length of other long bones and other parts of the body. Brachydactyly is an inherited, usually dominant trait...

  • Branch migration
    Branch migration
    Branch migration describes the ability of a DNA strand partially paired with its complement in a duplex to extend its pairing by displacing the resident strand with which it is homologous. This usually happens when two homologous double strands form a Holliday junction and the whole structure...

  • BRCA1
    BRCA1 is a human caretaker gene that produces a protein called breast cancer type 1 susceptibility protein, responsible for repairing DNA. The first evidence for the existence of the gene was provided by the King laboratory at UC Berkeley in 1990...

  • BRCA2
    BRCA2 is a protein that in humans is encoded by the BRCA2 gene.BRCA2 orthologs have been identified in most mammals for which complete genome data are available....

  • Breakage and reunion
  • Bridging cross
  • Bud
    In botany, a bud is an undeveloped or embryonic shoot and normally occurs in the axil of a leaf or at the tip of the stem. Once formed, a bud may remain for some time in a dormant condition, or it may form a shoot immediately. Buds may be specialized to develop flowers or short shoots, or may have...

  • Buoyant density
  • Burkitt lymphoma


  • Cancer
    Cancer , known medically as a malignant neoplasm, is a large group of different diseases, all involving unregulated cell growth. In cancer, cells divide and grow uncontrollably, forming malignant tumors, and invade nearby parts of the body. The cancer may also spread to more distant parts of the...

  • Candidate gene
    Candidate gene
    A candidate gene is a gene, located in a chromosome region suspected of being involved in the expression of a trait such as a disease, whose protein product suggests that it could be the gene in question...

  • Capillary array
  • Carcinogen
    A carcinogen is any substance, radionuclide, or radiation that is an agent directly involved in causing cancer. This may be due to the ability to damage the genome or to the disruption of cellular metabolic processes...

  • Carcinoma
    Carcinoma is the medical term for the most common type of cancer occurring in humans. Put simply, a carcinoma is a cancer that begins in a tissue that lines the inner or outer surfaces of the body, and that generally arises from cells originating in the endodermal or ectodermal germ layer during...

  • Carrier
    Genetic carrier
    A genetic carrier , is a person or other organism that has inherited a genetic trait or mutation, but who does not display that trait or show symptoms of the disease. They are, however, able to pass the gene onto their offspring, who may then express the gene...

  • Carrier testing
  • Cat coat genetics
    Cat coat genetics
    The genetics of cat coat coloration, pattern, length, and texture is a complex subject, and many different genes are involved.- Genes involved in albinism, dominant white, and white spotting :...

  • cDNA
  • cDNA library
    CDNA library
    A cDNA library is a combination of cloned cDNA fragments inserted into a collection of host cells, which together constitute some portion of the transcriptome of the organism. cDNA is produced from fully transcribed mRNA found in the nucleus and therefore contains only the expressed genes of an...

  • Cell
    Cell (biology)
    The cell is the basic structural and functional unit of all known living organisms. It is the smallest unit of life that is classified as a living thing, and is often called the building block of life. The Alberts text discusses how the "cellular building blocks" move to shape developing embryos....

  • Centimorgan
    In genetics, a centimorgan or map unit is a unit of recombinant frequency for measuring genetic linkage, defined as that distance between chromosome positions for which the expected average number of intervening chromosomal crossovers in a single generation is 0.01. It is often used to infer...

  • Central dogma of molecular biology
    Central dogma of molecular biology
    The central dogma of molecular biology was first articulated by Francis Crick in 1958 and re-stated in a Nature paper published in 1970:In other words, the process of producing proteins is irreversible: a protein cannot be used to create DNA....

  • Centromere
    A centromere is a region of DNA typically found near the middle of a chromosome where two identical sister chromatids come closest in contact. It is involved in cell division as the point of mitotic spindle attachment...

  • Chemical base
  • Chimeraplasty
    Chimeraplasty is a non-viral method of gene therapy. Chimeraplasty changes DNA sequences using a synthetic strand of RNA and DNA. This strand of RNA and DNA is known as a chimeraplast. The chimeraplast enters a cell and attaches itself to the target gene...

  • Chromomere
    A chromomere, also known as an idiomere, is one of the serially aligned beads or granules of an eukaryotic chromosome, resulting from local coiling of a continuous DNA thread. It is visible on a chromosome during the prophase of meiosis and mitosis...

  • Chromosomal crossover
    Chromosomal crossover
    Chromosomal crossover is an exchange of genetic material between homologous chromosomes. It is one of the final phases of genetic recombination, which occurs during prophase I of meiosis in a process called synapsis. Synapsis begins before the synaptonemal complex develops, and is not completed...

  • Chromosomal deletion
  • Chromosome
    A chromosome is an organized structure of DNA and protein found in cells. It is a single piece of coiled DNA containing many genes, regulatory elements and other nucleotide sequences. Chromosomes also contain DNA-bound proteins, which serve to package the DNA and control its functions.Chromosomes...

  • Chromosome aglet
  • Chromosome banding
  • Chromosome painting
  • Chromosome region p
  • Chromosome region q
  • Classical genetics
    Classical genetics
    Classical genetics consists of the technique and methodologies of genetics that predate the advent of molecular biology. A key discovery of classical genetics in eukaryotes was genetic linkage...

  • Cleft lip
  • Cleft palate
  • Clinical geneticist
  • Clone (genetics)
  • Clone bank
  • Cloned DNA
  • Cloning
    Cloning in biology is the process of producing similar populations of genetically identical individuals that occurs in nature when organisms such as bacteria, insects or plants reproduce asexually. Cloning in biotechnology refers to processes used to create copies of DNA fragments , cells , or...

  • Cloning vector
    Cloning vector
    A cloning vector is a small piece of DNA into which a foreign DNA fragment can be inserted. The insertion of the fragment into the cloning vector is carried out by treating the vehicle and the foreign DNA with a restriction enzyme that creates the same overhang, then ligating the fragments...

  • Coccus
    Coccus can be used to describe any bacterium that has a spherical shape. It is one of the three distinct types of bacteria shapes, the other two being bacillus and spirillum cells...

  • Code
    A code is a rule for converting a piece of information into another form or representation , not necessarily of the same type....

  • Code dictionary
  • Coding strand
    Coding strand
    When referring to DNA transcription, the coding strand is the DNA strand which has the same base sequence as the RNA transcript produced...

  • Codominance
    Codominance refers to a relationship between two alleles of a gene. It occurs when the contributions of both alleles at a single locus are visible and do not overpower each other in the phenotype....

  • Codon
  • Codon usage bias
    Codon usage bias
    Codon usage bias refers to differences in the frequency of occurrence of synonymous codons in coding DNA. A codon is a series of three nucleotides that encodes a specific amino acid residue in a polypeptide chain or for the termination of translation .There are 64 different codons but only 20...

     aka Codon preference
  • Cohesive end
  • Cointegrate
    A cointegrate is the intermediate molecule which donor DNA and target DNA covalently bind during the formation of a Holliday junction....

  • Col plasmid
  • Colicinogenic factor
  • Colonoscopy
    Colonoscopy is the endoscopic examination of the large bowel and the distal part of the small bowel with a CCD camera or a fiber optic camera on a flexible tube passed through the anus. It may provide a visual diagnosis and grants the opportunity for biopsy or removal of suspected...

  • Colony
    In politics and history, a colony is a territory under the immediate political control of a state. For colonies in antiquity, city-states would often found their own colonies. Some colonies were historically countries, while others were territories without definite statehood from their inception....

  • Common ancestry
  • Comparative genomics
    Comparative genomics
    Comparative genomics is the study of the relationship of genome structure and function across different biological species or strains. Comparative genomics is an attempt to take advantage of the information provided by the signatures of selection to understand the function and evolutionary...

  • Compartment
  • Competence factor
  • Competent
    Competence (biology)
    In microbiology, genetics, cell biology and molecular biology, competence is the ability of a cell to take up extracellular DNA from its environment...

  • Complementarity genes
  • Complementary DNA
    Complementary DNA
    In genetics, complementary DNA is DNA synthesized from a messenger RNA template in a reaction catalyzed by the enzyme reverse transcriptase and the enzyme DNA polymerase. cDNA is often used to clone eukaryotic genes in prokaryotes...

  • Complementation
    Complementation (genetics)
    In genetics, complementation refers to a relationship between two different strains of an organism which both have homozygous recessive mutations that produce the same phenotype . These strains are true breeding for their mutation...

  • Complementation test
  • Complete linkage
    Complete linkage
    In genetics complete linkage is defined as the state in which two loci are so close together that alleles of these loci are virtually never separated by crossing over. During reproduction, chromosomes on the same chromosome pair, exchange sections of DNA. As a result, genes that were originally on...

  • Complex trait
  • Component of fitness
  • Composite transposon
    Composite transposon
    A composite transposon is similar in function to simple transposons and Insertion Sequence elements in that it has protein coding DNA segments flanked by inverted, repeated sequences that can be recognized by transposase enzymes. A composite transposon, however, is flanked by two separate IS...

  • Concordance
    Concordance (genetics)
    Concordance as used in genetics usually means the presence of the same trait in both members of a pair of twins. However, the strict definition is the probability that a pair of individuals will both have a certain characteristic, given that one of the pair has the characteristic. For example,...

  • Conditional mutation
  • Confidence limits
  • Confidentiality
    Confidentiality is an ethical principle associated with several professions . In ethics, and in law and alternative forms of legal resolution such as mediation, some types of communication between a person and one of these professionals are "privileged" and may not be discussed or divulged to...

  • Congenital
  • Conjugation tube
  • Consanguineous
  • Consanguinity
    Consanguinity refers to the property of being from the same kinship as another person. In that respect, consanguinity is the quality of being descended from the same ancestor as another person...

  • Consensus sequence
    Consensus sequence
    In molecular biology and bioinformatics, consensus sequence refers to the most common nucleotide or amino acid at a particular position after multiple sequences are aligned. A consensus sequence is a way of representing the results of a multiple sequence alignment, where related sequences are...

  • Conservative change
  • Conserved sequence
    Conserved sequence
    In biology, conserved sequences are similar or identical sequences that occur within nucleic acid sequences , protein sequences, protein structures or polymeric carbohydrates across species or within different molecules produced by the same organism...

  • Constant region
  • Constitutive
  • Contig
    A contig is a set of overlapping DNA segments that together represent a consensus region of DNA. In bottom-up sequencing projects, a contig refers to overlapping sequence data ; in top-down sequencing projects, contig refers to the overlapping clones that form a physical map of the genome that is...

  • Contig map
  • Contig maps
  • Contiguous genes
  • Continuous variation
  • Controlling element
  • Copper fist
    Copper fist
    Copper fist is an N-terminal domain involved in copper-dependent DNA binding. It is named for its resemblance to a fist.It can be found in some fungal transcription factors. These proteins activate the transcription of the metallothionein gene in response to copper. Metallothionein maintains copper...

  • Copy-choice model
  • Corepressor
  • Correction
    Correction may refer to:* An euphemism for punishment* Correction , the posting of a notice of a mistake in a past issue of a newspaper* Correction , in financial markets, a short-term price decline...

  • Cosegregation
  • Cosmid
    A cosmid, first described by Collins and Hohn in 1978, is a type of hybrid plasmid that contains cos sequences, DNA sequences originally from the Lambda phage. Cosmids can be used to build genomic libraries....

  • Cosmids
  • Cot value
  • Cotransduction
  • Cotransformation
    Cotransformation is the simultaneous transformation of two or more genes.Only genes in the same chromosomal vicinity can be transformed; the closer together the genes lie, the more frequently they will be cotransformed...

  • Coupling
    Genetic linkage
    Genetic linkage is the tendency of certain loci or alleles to be inherited together. Genetic loci that are physically close to one another on the same chromosome tend to stay together during meiosis, and are thus genetically linked.-Background:...

  • Covariance
    In probability theory and statistics, covariance is a measure of how much two variables change together. Variance is a special case of the covariance when the two variables are identical.- Definition :...

  • cpDNA
  • CpG island
    CpG island
    In genetics, CpG islands or CG islands are genomic regions that contain a high frequency of CpG sites but to date objective definitions for CpG islands are limited. In mammalian genomes, CpG islands are typically 300-3,000 base pairs in length. They are in and near approximately 40% of promoters of...

  • Craniosynostosis
    Craniosynostosis is a condition in which one or more of the fibrous sutures in an infant skull prematurely fuses by ossification, thereby changing the growth pattern of the skull...

  • Cri du chat
    Cri du chat
    Cri du chat syndrome, also known as chromosome 5p deletion syndrome, 5p minus syndrome or Lejeune’s syndrome, is a rare genetic disorder due to a missing part of chromosome 5. Its name is a French term referring to the characteristic cat-like cry of affected children. It was first described by...

  • cRNA
  • Cross
    A cross is a geometrical figure consisting of two lines or bars perpendicular to each other, dividing one or two of the lines in half. The lines usually run vertically and horizontally; if they run obliquely, the design is technically termed a saltire, although the arms of a saltire need not meet...

  • Cross-fertilization
  • Crossbreed
    A crossbreed or crossbred usually refers to an animal with purebred parents of two different breeds, varieties, or populations. Crossbreeding refers to the process of breeding such an animal, often with the intention to create offspring that share the traits of both parent lineages, or producing...

  • Crossover
    Chromosomal crossover
    Chromosomal crossover is an exchange of genetic material between homologous chromosomes. It is one of the final phases of genetic recombination, which occurs during prophase I of meiosis in a process called synapsis. Synapsis begins before the synaptonemal complex develops, and is not completed...

  • Crossover suppressor
  • Crossovers
    Chromosomal crossover
    Chromosomal crossover is an exchange of genetic material between homologous chromosomes. It is one of the final phases of genetic recombination, which occurs during prophase I of meiosis in a process called synapsis. Synapsis begins before the synaptonemal complex develops, and is not completed...

  • Cryptic coloration
  • Culture
    Microbiological culture
    A microbiological culture, or microbial culture, is a method of multiplying microbial organisms by letting them reproduce in predetermined culture media under controlled laboratory conditions. Microbial cultures are used to determine the type of organism, its abundance in the sample being tested,...

  • Cyclic AMP
  • Cys
    CYS may refer to:* Cysteine an amino-acid* IATA airport code for Cheyenne Regional Airport.* California Youth Symphony, a San Francisco Bay Area symphony orchestra for young musicians* Count Your Sheep, a webcomic by Adrian Ramos...

  • Cystic fibrosis
    Cystic fibrosis
    Cystic fibrosis is a recessive genetic disease affecting most critically the lungs, and also the pancreas, liver, and intestine...

  • Cytidine
    Cytidine is a nucleoside molecule that is formed when cytosine is attached to a ribose ring via a β-N1-glycosidic bond...

  • Cytochrome
    Cytochromes are, in general, membrane-bound hemoproteins that contain heme groups and carry out electron transport.They are found either as monomeric proteins or as subunits of bigger enzymatic complexes that catalyze redox reactions....

  • Cytogenetic map
  • Cytogenetics
    Cytogenetics is a branch of genetics that is concerned with the study of the structure and function of the cell, especially the chromosomes. It includes routine analysis of G-Banded chromosomes, other cytogenetic banding techniques, as well as molecular cytogenetics such as fluorescent in situ...

  • Cytohet
    In genetics, a cytohet is a eukaryotic cell whose non-nucleic genome is heterozygous.The non-nucleic genome of eukaryotic cells exists in cytoplasmic organelles, namely the chloroplasts and the mitochondria...

  • Cytokinesis
    Cytokinesis is the process in which the cytoplasm of a single eukaryotic cell is divided to form two daughter cells. It usually initiates during the late stages of mitosis, and sometimes meiosis, splitting a binucleate cell in two, to ensure that chromosome number is maintained from one generation...

  • Cytological band
  • Cytological map
  • Cytoplasm
    The cytoplasm is a small gel-like substance residing between the cell membrane holding all the cell's internal sub-structures , except for the nucleus. All the contents of the cells of prokaryote organisms are contained within the cytoplasm...

  • Cytoplasmic trait
    Extranuclear Inheritance
    Extranuclear inheritance is the transmission of genes that occur outside the nucleus. It is found in most eukaryotes and is commonly known to occur in cytoplasmic organelles such as mitochondria and chloroplasts or from cellular parasites like viruses or bacteria .- Extranuclear Inheritance of...

  • Cytosine
    Cytosine is one of the four main bases found in DNA and RNA, along with adenine, guanine, and thymine . It is a pyrimidine derivative, with a heterocyclic aromatic ring and two substituents attached . The nucleoside of cytosine is cytidine...

  • Cytosol
    The cytosol or intracellular fluid is the liquid found inside cells, that is separated into compartments by membranes. For example, the mitochondrial matrix separates the mitochondrion into compartments....


  • D-loop
    In molecular biology, a displacement loop or D-loop is a DNA structure where the two strands of a double-stranded DNA molecule are separated for a stretch and held apart by a third strand of DNA. The third strand has a base sequence which is complementary to one of the main strands and pairs with...

  • Darwinian fitness
  • Data warehouse
    Data warehouse
    In computing, a data warehouse is a database used for reporting and analysis. The data stored in the warehouse is uploaded from the operational systems. The data may pass through an operational data store for additional operations before it is used in the DW for reporting.A data warehouse...

  • Dauermodification
  • Deficiency
    Genetic deletion
    In genetics, a deletion is a mutation in which a part of a chromosome or a sequence of DNA is missing. Deletion is the loss of genetic material. Any number of nucleotides can be deleted, from a single base to an entire piece of chromosome...

  • Degenerate code
  • Degenerate codon
  • Degrees of freedom (physics and chemistry)
    Degrees of freedom (physics and chemistry)
    A degree of freedom is an independent physical parameter, often called a dimension, in the formal description of the state of a physical system...

  • Deletion
  • Deletion chromosome
  • Deletion map
  • Deletion mapping
    Deletion mapping
    In genetics and especially genetic engineering, deletion mapping is a technique used to ascertain the location of mutation sites within a gene....

  • Deme (Biology)
    Deme (biology)
    In biology, a deme is a term for a local population of organisms of one species that actively interbreed with one another and share a distinct gene pool...

  • Dementia
    Dementia is a serious loss of cognitive ability in a previously unimpaired person, beyond what might be expected from normal aging...

  • Denaturation
    Denaturation (biochemistry)
    Denaturation is a process in which proteins or nucleic acids lose their tertiary structure and secondary structure by application of some external stress or compound, such as a strong acid or base, a concentrated inorganic salt, an organic solvent , or heat...

  • Denaturation map
  • Denominator element
  • Deoxyribonuclease
    A deoxyribonuclease is any enzyme that catalyzes the hydrolytic cleavage of phosphodiester linkages in the DNA backbone. Thus, deoxyribonucleases are one type of nuclease...

  • Deoxyribonucleotide
    A deoxyribonucleotide is the monomer, or single unit, of DNA, or deoxyribonucleic acid. Each deoxyribonucleotide comprises three parts: a nitrogenous base, a deoxyribose sugar, and one phosphate group. The nitrogenous base is always bonded to the 1' carbon of the deoxyribose, which is distinguished...

  • Deoxyribose
    Deoxyribose, more, precisely 2-deoxyribose, is a monosaccharide with idealized formula H---3-H. Its name indicates that it is a deoxy sugar, meaning that it is derived from the sugar ribose by loss of an oxygen atom...

  • Depauperate fauna
  • Derepressed
  • Determinant
    In linear algebra, the determinant is a value associated with a square matrix. It can be computed from the entries of the matrix by a specific arithmetic expression, while other ways to determine its value exist as well...

  • Determination
  • Deterministic
  • Developmental biology
    Developmental biology
    Developmental biology is the study of the process by which organisms grow and develop. Modern developmental biology studies the genetic control of cell growth, differentiation and "morphogenesis", which is the process that gives rise to tissues, organs and anatomy.- Related fields of study...

  • Diabetes mellitus
    Diabetes mellitus
    Diabetes mellitus, often simply referred to as diabetes, is a group of metabolic diseases in which a person has high blood sugar, either because the body does not produce enough insulin, or because cells do not respond to the insulin that is produced...

  • Diakinesis
  • Dicentric bridge
  • Dicentric chromosome
    Dicentric chromosome
    Dicentric chromosome is an aberrant chromosome having two centromeres. Dicentric chromosomes form when two chromosome segments , each with a centromere, fuse end to end, with loss of their acentric fragments...

  • Dictyotene
  • Dideoxy method
  • Differentiation
  • Dihybrid
  • Dihybrid cross
    Dihybrid cross
    A dihybrid cross is a cross between F1 offspring of two individuals that differ in two traits of particular interest. For example: RRyy/rrYY or RRYY/rryy parents result in F1 offspring that are heterozygous for both R and Y ....

  • Dimerization
  • Dimorphism
  • Dioecious plant
  • Diploid
  • Directed evolution
    Directed evolution
    thumb|250px|right|An example of a possible round to evolve a protein based fluorescent sensor for a specific analyte using two consecutive FACS sortings...

  • Directed mutagenesis
    Directed mutagenesis
    Directed mutagenesis, also known as directed mutation, is a hypothesis proposing that organisms can respond to environmental stresses through directing mutations to certain genes or areas of the genome....

  • Directed sequencing
  • Discrete generations
  • Disease
    A disease is an abnormal condition affecting the body of an organism. It is often construed to be a medical condition associated with specific symptoms and signs. It may be caused by external factors, such as infectious disease, or it may be caused by internal dysfunctions, such as autoimmune...

  • Disruptive selection
    Disruptive selection
    Disruptive selection, also called diversifying selection, describes changes in population genetics in which extreme values for a trait are favored over intermediate values. In this case, the variance of the trait increases and the population is divided into two distinct groups...

  • Distribution
    Distribution (mathematics)
    In mathematical analysis, distributions are objects that generalize functions. Distributions make it possible to differentiate functions whose derivatives do not exist in the classical sense. In particular, any locally integrable function has a distributional derivative...

  • DMD
    Duchenne muscular dystrophy
    Duchenne muscular dystrophy is a recessive X-linked form of muscular dystrophy, which results in muscle degeneration, difficulty walking, breathing, and death. The incidence is 1 in 3,000 boys. Females and males are affected, though females are rarely affected and are more often carriers...

  • DNA
    Deoxyribonucleic acid is a nucleic acid that contains the genetic instructions used in the development and functioning of all known living organisms . The DNA segments that carry this genetic information are called genes, but other DNA sequences have structural purposes, or are involved in...

  • DNA amplification
  • DNA bank
    DNA bank
    A DNA bank is a repository of DNA, usually used for research. The NIAS DNA Bank, for example, collects the DNA of agricultural organisms, such as rice and fish, for scientific research. Most DNA provided by DNA banks is used for studies to attempt to develop more productive or more environmentally...

  • DNA clone
  • DNA cloning
  • DNA fingerprint
  • DNA glycosylase
  • DNA gyrase
    DNA gyrase
    DNA gyrase, often referred to simply as gyrase, is an enzyme that relieves strain while double-stranded DNA is being unwound by helicase. This causes negative supercoiling of the DNA...

  • DNA hybridization
  • DNA ligase
    DNA ligase
    In molecular biology, DNA ligase is a specific type of enzyme, a ligase, that repairs single-stranded discontinuities in double stranded DNA molecules, in simple words strands that have double-strand break . Purified DNA ligase is used in gene cloning to join DNA molecules together...

  • DNA marker
  • DNA polymerase
    DNA polymerase
    A DNA polymerase is an enzyme that helps catalyze in the polymerization of deoxyribonucleotides into a DNA strand. DNA polymerases are best known for their feedback role in DNA replication, in which the polymerase "reads" an intact DNA strand as a template and uses it to synthesize the new strand....

  • DNA probe
  • DNA repair genes
  • DNA replication
    DNA replication
    DNA replication is a biological process that occurs in all living organisms and copies their DNA; it is the basis for biological inheritance. The process starts with one double-stranded DNA molecule and produces two identical copies of the molecule...

  • DNA sequence
    DNA sequence
    The sequence or primary structure of a nucleic acid is the composition of atoms that make up the nucleic acid and the chemical bonds that bond those atoms. Because nucleic acids, such as DNA and RNA, are unbranched polymers, this specification is equivalent to specifying the sequence of...

  • DNA sequencing
    DNA sequencing
    DNA sequencing includes several methods and technologies that are used for determining the order of the nucleotide bases—adenine, guanine, cytosine, and thymine—in a molecule of DNA....

  • Docking protein
  • DOE
    Doe may refer to:* An adult female in some animal species; see List of animal names* Doe people, a people of coastal Tanzania* Doe language, spoken by the Doe people* Doe River, a river in Tennessee, USA...

  • Domain
    Protein domain
    A protein domain is a part of protein sequence and structure that can evolve, function, and exist independently of the rest of the protein chain. Each domain forms a compact three-dimensional structure and often can be independently stable and folded. Many proteins consist of several structural...

  • Dominance variance
  • Dominant
  • Dominant allele
  • Dominant phenotype
  • Dosage compensation
    Dosage compensation
    Dosage compensation, also known as Ohno's Hypothesis, is a hypothetical genetic regulatory mechanism which operates to equalize the phenotypic expression of characteristics determined by genes on the X chromosome so that they are equally expressed in the human XY male and the XX female. In 2006,...

  • Dose
    Dose (biochemistry)
    A dose is a quantity of something that may impact an organism biologically; the greater the quantity, the larger the dose. In nutrition, the term is usually applied to how much of a specific nutrient is in a person's diet or in a particular food, meal, or dietary supplement...

  • Dot blotting
  • Double crossover(Bad Link)
  • Double digest
  • Double helix
  • Double infection
  • Double reduction
  • Doublesex
    Doublesex is a gene that is involved in the sex determination system of the fruit fly Drosophila melanogaster.-Sex determination:...

  • Down syndrome
    Down syndrome
    Down syndrome, or Down's syndrome, trisomy 21, is a chromosomal condition caused by the presence of all or part of an extra 21st chromosome. It is named after John Langdon Down, the British physician who described the syndrome in 1866. The condition was clinically described earlier in the 19th...

  • Downstream
  • Draft sequence
  • Duplicate gene
  • Dwarfism
    Dwarfism is short stature resulting from a medical condition. It is sometimes defined as an adult height of less than 4 feet 10 inches  , although this definition is problematic because short stature in itself is not a disorder....

  • Dyad
  • Dyad symmetry
    Dyad symmetry
    In genetics, dyad symmetry refers to two areas of a DNA strand whose base pair sequences are inverted repeats of each other. They are often described as palindromes....

  • Dystonia
    Dystonia is a neurological movement disorder, in which sustained muscle contractions cause twisting and repetitive movements or abnormal postures. The disorder may be hereditary or caused by other factors such as birth-related or other physical trauma, infection, poisoning or reaction to...


  • E (exit site)
    A ribosome is a component of cells that assembles the twenty specific amino acid molecules to form the particular protein molecule determined by the nucleotide sequence of an RNA molecule....

  • Ecdysone
    Ecdysone is a steroidal prohormone of the major insect molting hormone 20-hydroxyecdysone, which is secreted from the prothoracic glands. Insect molting hormones are generally called ecdysteroids. Ecdysteroids act as moulting hormones of arthropods but also occur in other related phyla where they...

  • Ecological genetics
    Ecological genetics
    Ecological genetics is the study of genetics in natural populations.This contrasts with classical genetics, which works mostly on crosses between laboratory strains, and DNA sequence analysis, which studies genes at the molecular level....

  • Ectopic expression
    Ectopic expression
    Ectopic expression is the expression of a gene in an abnormal place in an organism. This can be caused by a disease, or it can be artificially produced as a way to help determine what the function of that gene is....

  • Ectopic integration
  • Electrophoresis
    Electrophoresis, also called cataphoresis, is the motion of dispersed particles relative to a fluid under the influence of a spatially uniform electric field. This electrokinetic phenomenon was observed for the first time in 1807 by Reuss , who noticed that the application of a constant electric...

  • Electroporation
    Electroporation, or electropermeabilization, is a significant increase in the electrical conductivity and permeability of the cell plasma membrane caused by an externally applied electrical field...

  • ELSI
  • Endogenote
  • Endomitosis
  • Endonuclease
    Endonucleases are enzymes that cleave the phosphodiester bond within a polynucleotide chain, in contrast to exonucleases, which cleave phosphodiester bonds at the end of a polynucleotide chain. Typically, a restriction site will be a palindromic sequence four to six nucleotides long. Most...

  • Endopolyploidy
  • Endosperm
    Endosperm is the tissue produced inside the seeds of most flowering plants around the time of fertilization. It surrounds the embryo and provides nutrition in the form of starch, though it can also contain oils and protein. This makes endosperm an important source of nutrition in human diet...

  • Enforced outbreeding
  • Enhancer
    Enhancer (genetics)
    In genetics, an enhancer is a short region of DNA that can be bound with proteins to enhance transcription levels of genes in a gene cluster...

  • Enhancer trap
    Enhancer trap
    An enhancer trap is a transgenic construction for the identification of enhancers, produced by the fusing of two proteins, genes for which are inserted into the genome. The enhancer trap structure contains a mobile element usually some sort of P element and a reporter gene...

  • Enriched medium
  • Enucleate cell
  • Enzyme
    Enzymes are proteins that catalyze chemical reactions. In enzymatic reactions, the molecules at the beginning of the process, called substrates, are converted into different molecules, called products. Almost all chemical reactions in a biological cell need enzymes in order to occur at rates...

  • Epigenetics
    In biology, and specifically genetics, epigenetics is the study of heritable changes in gene expression or cellular phenotype caused by mechanisms other than changes in the underlying DNA sequence – hence the name epi- -genetics...

  • Episome
  • Epistasis
    In genetics, epistasis is the phenomenon where the effects of one gene are modified by one or several other genes, which are sometimes called modifier genes. The gene whose phenotype is expressed is called epistatic, while the phenotype altered or suppressed is called hypostatic...

  • Equational division
  • Equivalence group
    Equivalence group
    An equivalence group is a biology term used to describe a set of unspecified cells that have the same developmental potential or ability to adopt various fates. Our current understanding suggests that equivalence groups are limited to cells of the same ancestry, also known as sibling cells...

  • Erythrocytes
  • Escherichia coli
    Escherichia coli
    Escherichia coli is a Gram-negative, rod-shaped bacterium that is commonly found in the lower intestine of warm-blooded organisms . Most E. coli strains are harmless, but some serotypes can cause serious food poisoning in humans, and are occasionally responsible for product recalls...

  • Ethics
    Ethics, also known as moral philosophy, is a branch of philosophy that addresses questions about morality—that is, concepts such as good and evil, right and wrong, virtue and vice, justice and crime, etc.Major branches of ethics include:...

  • Ethidium
  • Euchromatin
    Euchromatin is a lightly packed form of chromatin that is rich in gene concentration, and is often under active transcription. Unlike heterochromatin, it is found in both cells with nuclei and cells without nuclei...

  • Eugenics
    Eugenics is the "applied science or the bio-social movement which advocates the use of practices aimed at improving the genetic composition of a population", usually referring to human populations. The origins of the concept of eugenics began with certain interpretations of Mendelian inheritance,...

  • Eukaryote
    A eukaryote is an organism whose cells contain complex structures enclosed within membranes. Eukaryotes may more formally be referred to as the taxon Eukarya or Eukaryota. The defining membrane-bound structure that sets eukaryotic cells apart from prokaryotic cells is the nucleus, or nuclear...

  • Eukaryotic cell
    Eukaryotic Cell
    Eukaryotic Cell is an academic journal published by the American Society for Microbiology. The title is commonly abbreviated EC and the ISSN is 1535-9778 for the print version, and 1535-9786 for the electronic version....

  • Euploid
  • Euploidy
  • European Journal of Human Genetics
    European Journal of Human Genetics
    The European Journal of Human Genetics is the official journal of the European Society of Human Genetics. It focuses on human genetics, and is published monthly by the Nature Publishing Group...

  • Evolution
    Evolution is any change across successive generations in the heritable characteristics of biological populations. Evolutionary processes give rise to diversity at every level of biological organisation, including species, individual organisms and molecules such as DNA and proteins.Life on Earth...

  • Evolutionary rate
  • Excision repair
  • Exconjugant
  • Exogenote
    An exogenote is a DNA donor and usually occurs in mating of prokaryotic organisms.An exogenote is genetic material that is released into the environment by prokaryotic cells, usually upon their lysis...

  • Exogenous DNA
    Exogenous DNA
    Exogenous DNA refers to any deoxyribonucleic acid that originates outside of the organism of concern or study.The introduction of exogenous DNA into a cell is called...

  • Exon
    An exon is a nucleic acid sequence that is represented in the mature form of an RNA molecule either after portions of a precursor RNA have been removed by cis-splicing or when two or more precursor RNA molecules have been ligated by trans-splicing. The mature RNA molecule can be a messenger RNA...

  • Exon shuffling
    Exon shuffling
    Exon shuffling is a theory, introduced by Walter Gilbert in 1977, in which different exons either within a gene or between two nonallelic genes are occasionally mixed. Gilbert suggested that exons might each encode a single protein domain, establishing a kind of modular property...

  • Exonuclease
    Exonucleases are enzymes that work by cleaving nucleotides one at a time from the end of a polynucleotide chain. A hydrolyzing reaction that breaks phosphodiester bonds at either the 3’ or the 5’ end occurs. Its close relative is the endonuclease, which cleaves phosphodiester bonds in the middle ...

  • Experimental design
  • Expressed gene
  • Expression vector
    Expression vector
    An expression vector, otherwise known as an expression construct, is generally a plasmid that is used to introduce a specific gene into a target cell. Once the expression vector is inside the cell, the protein that is encoded by the gene is produced by the cellular-transcription and translation...

  • Expressivity
    Expressivity is a term used in genetics to refer to variations in a phenotype among individuals carrying a particular genotype. The term can be used to characterize qualitatively or quantitatively the extent of phenotypic variation given a particular genotype. The term is analogous to the...


  • F factor
  • F plus cell
  • F- cell
  • F-duction
  • F-pili
  • F1 generation
  • F2 generation
  • Factorial
    In mathematics, the factorial of a non-negative integer n, denoted by n!, is the product of all positive integers less than or equal to n...

  • Familial cancer
  • Familial trait
  • Family selection
  • Fanconi's anemia
  • Fate map
  • Fecundity selection
  • Feedback inhibition
  • Fibroblasts
  • Filial generation
  • Filter enrichment
  • Fimbriae
  • Fingerprint
    A fingerprint in its narrow sense is an impression left by the friction ridges of a human finger. In a wider use of the term, fingerprints are the traces of an impression from the friction ridges of any part of a human hand. A print from the foot can also leave an impression of friction ridges...

  • Fingerprinting
  • FISH (Fluorescent in situ hybridization
    Fluorescent in situ hybridization
    FISH is a cytogenetic technique developed by biomedical researchers in the early 1980s that is used to detect and localize the presence or absence of specific DNA sequences on chromosomes. FISH uses fluorescent probes that bind to only those parts of the chromosome with which they show a high...

  • Fitness (W)
  • Fixed allele
    Fixed allele
    A fixed allele is an allele that is the only variant that exists for that gene in all the population. A fixed allele is homozygous for all members of the population....

  • Fixed breakage point
  • Flow cytometry
    Flow cytometry
    Flow cytometry is a technique for counting and examining microscopic particles, such as cells and chromosomes, by suspending them in a stream of fluid and passing them by an electronic detection apparatus. It allows simultaneous multiparametric analysis of the physical and/or chemical...

  • Flow karyotyping
  • Fluctuation test
  • Fluorescent in situ hybridization
    Fluorescent in situ hybridization
    FISH is a cytogenetic technique developed by biomedical researchers in the early 1980s that is used to detect and localize the presence or absence of specific DNA sequences on chromosomes. FISH uses fluorescent probes that bind to only those parts of the chromosome with which they show a high...

  • FMET
  • Focus map
  • Footprinting
    Footprinting is the technique of gathering information about computer systems and the entities they belong to. This is done by employing various computer security techniques, as:*DNS queries*Network enumeration*Network queries...

  • Forensics
    Forensic science is the application of a broad spectrum of sciences to answer questions of interest to a legal system. This may be in relation to a crime or a civil action...

  • Forward mutation
  • Founder effect
    Founder effect
    In population genetics, the founder effect is the loss of genetic variation that occurs when a new population is established by a very small number of individuals from a larger population. It was first fully outlined by Ernst Mayr in 1942, using existing theoretical work by those such as Sewall...

  • Fragile site
  • Fragile X syndrome
    Fragile X syndrome
    Fragile X syndrome , Martin–Bell syndrome, or Escalante's syndrome , is a genetic syndrome that is the most commonly known single-gene cause of autism and the most common inherited cause of intellectual disability...

  • Frameshift
  • Frameshift mutation
    Frameshift mutation
    A frameshift mutation is a genetic mutation caused by indels of a number of nucleotides that is not evenly divisible by three from a DNA sequence...

  • Fraternal twin
  • Frequency histogram
  • Fruiting body
  • Full gene sequence
  • Functional allele
  • Functional genomics
    Functional genomics
    Functional genomics is a field of molecular biology that attempts to make use of the vast wealth of data produced by genomic projects to describe gene functions and interactions...

  • Fundamental number


  • G-banding
  • Galton Laboratory
    Galton Laboratory
    The Galton Laboratory, was a laboratory for research into human genetics based at University College London in London, United Kingdom. It was originally established in 1904, and became part of UCL's biology department in 1996....

  • Gamete
    A gamete is a cell that fuses with another cell during fertilization in organisms that reproduce sexually...

  • Gametophyte
    A gametophyte is the haploid, multicellular phase of plants and algae that undergo alternation of generations, with each of its cells containing only a single set of chromosomes....

  • Gastrulation
    Gastrulation is a phase early in the embryonic development of most animals, during which the single-layered blastula is reorganized into a trilaminar structure known as the gastrula. These three germ layers are known as the ectoderm, mesoderm, and endoderm.Gastrulation takes place after cleavage...

  • GC-rich area
  • Gel electrophoresis
    Gel electrophoresis
    Gel electrophoresis is a method used in clinical chemistry to separate proteins by charge and or size and in biochemistry and molecular biology to separate a mixed population of DNA and RNA fragments by length, to estimate the size of DNA and RNA fragments or to separate proteins by charge...

  • Gene
    A gene is a molecular unit of heredity of a living organism. It is a name given to some stretches of DNA and RNA that code for a type of protein or for an RNA chain that has a function in the organism. Living beings depend on genes, as they specify all proteins and functional RNA chains...

  • Gene amplification
  • Gene chip technology
  • Gene cloning
  • Gene complex
  • Gene conversion
    Gene conversion
    Gene conversion is an event in DNA genetic recombination, which occurs at high frequencies during meiotic division but which also occurs in somatic cells. It is a process by which DNA sequence information is transferred from one DNA helix to another DNA helix, whose sequence is altered.It is one...

  • Gene dose
  • Gene expression
    Gene expression
    Gene expression is the process by which information from a gene is used in the synthesis of a functional gene product. These products are often proteins, but in non-protein coding genes such as ribosomal RNA , transfer RNA or small nuclear RNA genes, the product is a functional RNA...

  • Gene family
    Gene family
    A gene family is a set of several similar genes, formed by duplication of a single original gene, and generally with similar biochemical functions...

  • Gene flow
    Gene flow
    In population genetics, gene flow is the transfer of alleles of genes from one population to another.Migration into or out of a population may be responsible for a marked change in allele frequencies...

  • Gene frequency
  • Gene fusion
  • Gene interaction
  • Gene library
    Gene library
    A genomic library is a population of host bacteria, each of which carries a DNA molecule that was inserted into a cloning vector, such that the collection of cloned DNA molecules represents the entire genome of the source organism...

  • Gene locus
  • Gene map
    Gene map
    A gene map is the descriptive representation of the structure of a single gene. It includes the DNA sequence of a gene with introns and exons, 3' or 5' transcribed-untranslated regions, termination signal, regulatory elements such as promoters, enhancers and it may include known mutations defining...

  • Gene mapping
    Gene mapping
    Gene mapping, also called genome mapping, is the creation of a genetic map assigning DNA fragments to chromosomes.When a genome is first investigated, this map is nonexistent. The map improves with the scientific progress and is perfect when the genomic DNA sequencing of the species has been...

  • Gene markers
  • Gene mutation
  • Gene orders
    Gene orders
    Gene orders is the permutation of genome arrangement. So far a fair amount of work trying to describe whether gene orders evolve according to a molecular clock or in jumps ....

  • Gene pair
  • Gene pool
    Gene pool
    In population genetics, a gene pool is the complete set of unique alleles in a species or population.- Description :A large gene pool indicates extensive genetic diversity, which is associated with robust populations that can survive bouts of intense selection...

  • Gene prediction
    Gene prediction
    In computational biology gene prediction or gene finding refers to the process of identifying the regions of genomic DNA that encode genes. This includes protein-coding genes as well as RNA genes, but may also include prediction of other functional elements such as regulatory regions...

  • Gene product
    Gene product
    A gene product is the biochemical material, either RNA or protein, resulting from expression of a gene. A measurement of the amount of gene product is sometimes used to infer how active a gene is. Abnormal amounts of gene product can be correlated with disease-causing alleles, such as the...

  • Gene regulatory network
    Gene regulatory network
    A gene regulatory network or genetic regulatory network is a collection of DNA segments in a cell whichinteract with each other indirectly and with other substances in the cell, thereby governing the rates at which genes in the network are transcribed into mRNA.In general, each mRNA molecule goes...

  • Gene testing
  • Gene theft
    Gene theft
    Gene theft or DNA theft is the act of acquiring the genetic material of another human being, often from a public place, without his or her permission. The DNA may be harvested from a wide variety of common objects such as discarded cigarettes, used coffee cups and hairbrushes...

  • Gene therapy
    Gene therapy
    Gene therapy is the insertion, alteration, or removal of genes within an individual's cells and biological tissues to treat disease. It is a technique for correcting defective genes that are responsible for disease development...

  • Gene transfer
  • Genetic algorithm
    Genetic algorithm
    A genetic algorithm is a search heuristic that mimics the process of natural evolution. This heuristic is routinely used to generate useful solutions to optimization and search problems...

  • Genetic architecture
    Genetic architecture
    Genetic architecture refers to the underlying genetic basis of a phenotypic trait. A synonymous term is the 'genotype-phenotype map', the way that genotypes map to the phenotypes....

  • Genetic carrier
    Genetic carrier
    A genetic carrier , is a person or other organism that has inherited a genetic trait or mutation, but who does not display that trait or show symptoms of the disease. They are, however, able to pass the gene onto their offspring, who may then express the gene...

  • Genetic code
    Genetic code
    The genetic code is the set of rules by which information encoded in genetic material is translated into proteins by living cells....

  • Genetic counseling
    Genetic counseling
    Genetic counseling or traveling is the process by which patients or relatives, at risk of an inherited disorder, are advised of the consequences and nature of the disorder, the probability of developing or transmitting it, and the options open to them in management and family planning...

  • Genetic deletion
    Genetic deletion
    In genetics, a deletion is a mutation in which a part of a chromosome or a sequence of DNA is missing. Deletion is the loss of genetic material. Any number of nucleotides can be deleted, from a single base to an entire piece of chromosome...

  • Genetic determinism
    Genetic determinism
    Genetic determinism is the belief that genes determine morphological and behavioral traits and do so with little or no influence from environmental factors....

  • Genetic disorder
    Genetic disorder
    A genetic disorder is an illness caused by abnormalities in genes or chromosomes, especially a condition that is present from before birth. Most genetic disorders are quite rare and affect one person in every several thousands or millions....

  • Genetic dissection
  • Genetic drift
    Genetic drift
    Genetic drift or allelic drift is the change in the frequency of a gene variant in a population due to random sampling.The alleles in the offspring are a sample of those in the parents, and chance has a role in determining whether a given individual survives and reproduces...

  • Genetic engineering
    Genetic engineering
    Genetic engineering, also called genetic modification, is the direct human manipulation of an organism's genome using modern DNA technology. It involves the introduction of foreign DNA or synthetic genes into the organism of interest...

  • Genetic genealogy
    Genetic genealogy
    Genetic genealogy is the application of genetics to traditional genealogy. Genetic genealogy involves the use of genealogical DNA testing to determine the level of genetic relationship between individuals.-History:...

  • Genetic history of Europe
    Genetic history of Europe
    The genetic history of Europe can be inferred from the patterns of genetic diversity across continents and time. The primary data to develop historical scenarios coming from sequences of mitochondrial, Y-chromosome and autosomal DNA from modern populations and if available from ancient DNA...

  • Genetic illness
  • Genetic informatics
  • Genetic linkage map
  • Genetic load
    Genetic load
    In population genetics, genetic load or genetic burden is a measure of the cost of lost alleles due to selection or mutation...

  • Genetic map
  • Genetic marker
    Genetic marker
    A genetic marker is a gene or DNA sequence with a known location on a chromosome that can be used to identify cells, individuals or species. It can be described as a variation that can be observed...

  • Genetic material
  • Genetic mosaic
  • Genetic polymorphism
  • Genetic screen
    Genetic screen
    A genetic screen is a procedure or test to identify and select individuals who possess a phenotype of interest. A genetic screen for new genes is often referred to as forward genetics as opposed to reverse genetics, the term for identifying mutant alleles in genes that are already known...

  • Genetic screening
  • Genetic testing
    Genetic testing
    Genetic testing is among the newest and most sophisticated of techniques used to test for genetic disorders which involves direct examination of the DNA molecule itself. Other genetic tests include biochemical tests for such gene products as enzymes and other proteins and for microscopic...

  • Genetic variance
  • Genetic variation
    Genetic variation
    Genetic variation, variation in alleles of genes, occurs both within and among populations. Genetic variation is important because it provides the “raw material” for natural selection. Genetic variation is brought about by mutation, a change in a chemical structure of a gene. Polyploidy is an...

  • Geneticist
    A geneticist is a biologist who studies genetics, the science of genes, heredity, and variation of organisms. A geneticist can be employed as a researcher or lecturer. Some geneticists perform experiments and analyze data to interpret the inheritance of skills. A geneticist is also a Consultant or...

  • Genetics
    Genetics , a discipline of biology, is the science of genes, heredity, and variation in living organisms....

  • Genetics and Archaeogenetics of South Asia
    Genetics and Archaeogenetics of South Asia
    The study of the genetics and archaeogenetics of the ethnic groups of South Asia aims at uncovering these groups' genetic history. The geographic position of India makes Indian populations important for the study of the early dispersal of all human populations on the Eurasian continent.The Indian...

  • Genetics experiments
  • Genic balance theory
  • Genome
    In modern molecular biology and genetics, the genome is the entirety of an organism's hereditary information. It is encoded either in DNA or, for many types of virus, in RNA. The genome includes both the genes and the non-coding sequences of the DNA/RNA....

  • Genome map
  • Genome project
    Genome project
    Genome projects are scientific endeavours that ultimately aim to determine the complete genome sequence of an organism and to annotate protein-coding genes and other important genome-encoded features...

  • Genome screen
  • Genomic library
  • Genomic sequence
  • Genomics
    Genomics is a discipline in genetics concerning the study of the genomes of organisms. The field includes intensive efforts to determine the entire DNA sequence of organisms and fine-scale genetic mapping efforts. The field also includes studies of intragenomic phenomena such as heterosis,...

  • Genophore
  • Genotype
    The genotype is the genetic makeup of a cell, an organism, or an individual usually with reference to a specific character under consideration...

  • Germ cell
    Germ cell
    A germ cell is any biological cell that gives rise to the gametes of an organism that reproduces sexually. In many animals, the germ cells originate near the gut of an embryo and migrate to the developing gonads. There, they undergo cell division of two types, mitosis and meiosis, followed by...

  • Germ line
  • Germ-line theory
  • Germinal mutation
  • Germline mutation
    Germline mutation
    A germline mutation is any detectable and heritable variation in the lineage of germ cells. Mutations in these cells are transmitted to offspring, while, on the other hand, those in somatic cells are not. A germline mutation gives rise to a constitutional mutation in the offspring, that is, a...

  • Giemsa stain
    Giemsa stain
    Giemsa stain, named after Gustav Giemsa, an early German microbiologist, is used in cytogenetics and for the histopathological diagnosis of malaria and other parasites.-Uses:...

  • Gln
    Glutamine is one of the 20 amino acids encoded by the standard genetic code. It is not recognized as an essential amino acid but may become conditionally essential in certain situations, including intensive athletic training or certain gastrointestinal disorders...

  • Glutamic acid
    Glutamic acid
    Glutamic acid is one of the 20 proteinogenic amino acids, and its codons are GAA and GAG. It is a non-essential amino acid. The carboxylate anions and salts of glutamic acid are known as glutamates...

  • Gly
  • God gene
    God gene
    The God gene hypothesis proposes that a specific gene predisposes humans towards spiritual or mystic experiences. The idea has been postulated by geneticist Dean Hamer, the director of the Gene Structure and Regulation Unit at the U.S...

  • Gradient
    In vector calculus, the gradient of a scalar field is a vector field that points in the direction of the greatest rate of increase of the scalar field, and whose magnitude is the greatest rate of change....

  • Gray crescent
  • gRNA
  • Ground state
    Ground state
    The ground state of a quantum mechanical system is its lowest-energy state; the energy of the ground state is known as the zero-point energy of the system. An excited state is any state with energy greater than the ground state...

  • Group 1 intron
  • Group II intron
    Group II intron
    Group II introns are a large class of self-catalytic ribozymes as well as mobile genetic element found within the genes of all three domains of life. Ribozyme activity can occur under high-salt conditions in vitro. However, assistance from proteins is required for in vivo splicing...

  • Group selection
    Group selection
    In evolutionary biology, group selection refers to the idea that alleles can become fixed or spread in a population because of the benefits they bestow on groups, regardless of the alleles' effect on the fitness of individuals within that group....

  • Guanine
    Guanine is one of the four main nucleobases found in the nucleic acids DNA and RNA, the others being adenine, cytosine, and thymine . In DNA, guanine is paired with cytosine. With the formula C5H5N5O, guanine is a derivative of purine, consisting of a fused pyrimidine-imidazole ring system with...

  • Guanosine
    Guanosine is a purine nucleoside comprising guanine attached to a ribose ring via a β-N9-glycosidic bond. Guanosine can be phosphorylated to become guanosine monophosphate , cyclic guanosine monophosphate , guanosine diphosphate , and guanosine triphosphate...

  • Guide RNA
    Guide RNA
    Guide RNAs are the RNAs that guide the insertion or deletion of uridine residues into mitochondrial mRNAs in kinetoplastid protists in a process known as RNA editing.-Overview of gRNA-directed editing:...

  • Gynandromorph
    A gynandromorph is an organism that contains both male and female characteristics. The term gynandromorph, from Greek "gyne" female and "andro" male, is mainly used in the field of Lepidopterology or entomology...


  • H-Y antigen
  • Haemoglobin (hb)
  • Haemophilia
    Haemophilia is a group of hereditary genetic disorders that impair the body's ability to control blood clotting or coagulation, which is used to stop bleeding when a blood vessel is broken. Haemophilia A is the most common form of the disorder, present in about 1 in 5,000–10,000 male births...

  • Haplodiploidy
  • Haploid
  • Haploidization
  • Haploinsufficiency
    Haploinsufficiency occurs when a diploid organism only has a single functional copy of a gene and the single functional copy of the gene does not produce enough of a gene product to bring about a wild-type condition, leading to an abnormal or diseased state...

  • Haplotype
    A haplotype in genetics is a combination of alleles at adjacent locations on the chromosome that are transmitted together...

  • Hardy-Weinberg Law
  • Harlequin chromosome
  • HAT medium
    HAT medium
    HAT Medium is a selection medium for mammalian cell culture, which relies on the combination of aminopterin, a drug that acts as a powerful folate metabolism inhibitor by inhibiting dihydrofolate reductase, with hypoxanthine and thymidine which are intermediates in DNA synthesis...

  • Hayflick limit
    Hayflick limit
    The Hayflick limit is the number of times a normal cell population will divide before it stops, presumably because the telomeres reach a critical length....

  • Heat-shock protein
  • Helicase
    Helicases are a class of enzymes vital to all living organisms. They are motor proteins that move directionally along a nucleic acid phosphodiester backbone, separating two annealed nucleic acid strands using energy derived from ATP hydrolysis.-Function:Many cellular processes Helicases are a...

  • Hemizygous
  • Hemizygous gene
  • Hemophilia
  • Hereditary cancer
  • Hereditary mutation
  • Heredity
    Heredity is the passing of traits to offspring . This is the process by which an offspring cell or organism acquires or becomes predisposed to the characteristics of its parent cell or organism. Through heredity, variations exhibited by individuals can accumulate and cause some species to evolve...

  • Heritability
    The Heritability of a population is the proportion of observable differences between individuals that is due to genetic differences. Factors including genetics, environment and random chance can all contribute to the variation between individuals in their observable characteristics...

  • Hermaphrodite
    In biology, a hermaphrodite is an organism that has reproductive organs normally associated with both male and female sexes.Many taxonomic groups of animals do not have separate sexes. In these groups, hermaphroditism is a normal condition, enabling a form of sexual reproduction in which both...

  • Heterochromatin
    Heterochromatin is a tightly packed form of DNA, which comes in different varieties. These varieties lie on a continuum between the two extremes of constitutive and facultative heterochromatin...

  • Heteroduplex
    A heteroduplex is a double-stranded molecule of nucleic acid originated through the genetic recombination of single complementary strands derived from different sources, such as from different homologous chromosomes or even from different organisms....

  • Heteroduplex DNA
  • Heteroduplex mapping
  • Heterogametic sex
    Heterogametic sex
    Heterogametic sex refers to the sex of a species in which the sex chromosomes are not the same. For example, in humans, males, with an X and a Y sex chromosome, would be referred to as the heterogametic sex, and females having two X sex chromosomes would be referred to as the homogametic...

  • Heterogamy
  • Heterogeneity
  • Heterokaryon
    A heterokaryon is a cell that contains multiple, genetically different nuclei. This can occur naturally, such as in the mycelium of fungi during sexual reproduction, or artificially as formed by the experimental fusion of two genetically different cells. A medical example is a heterokaryon composed...

  • Heterokaryon test
  • Heteroplasmon
  • Heteroplasmy
    Heteroplasmy is the presence of a mixture of more than one type of an organellar genome within a cell or individual...

  • Heterothallic
    Heterothallic species have sexes that reside in different individuals....

  • Heterothallic fungus
  • Heterotroph
    A heterotroph is an organism that cannot fix carbon and uses organic carbon for growth. This contrasts with autotrophs, such as plants and algae, which can use energy from sunlight or inorganic compounds to produce organic compounds such as carbohydrates, fats, and proteins from inorganic carbon...

  • Heterozygosity
  • Heterozygote
  • Heterozygous
  • Heterozygous DNA
  • Hexaploid
  • Hfr
  • HGP
  • HHMI
  • Himalayan
  • His
    Histidine Histidine, an essential amino acid, has a positively charged imidazole functional group. It is one of the 22 proteinogenic amino acids. Its codons are CAU and CAC. Histidine was first isolated by German physician Albrecht Kossel in 1896. Histidine is an essential amino acid in humans...

  • Histone
    In biology, histones are highly alkaline proteins found in eukaryotic cell nuclei that package and order the DNA into structural units called nucleosomes. They are the chief protein components of chromatin, acting as spools around which DNA winds, and play a role in gene regulation...

  • HnRNA
  • Hogness box
  • Holandric trait
  • Holoenzyme
  • Holoprosencephaly
    Holoprosencephaly is a cephalic disorder in which the prosencephalon fails to develop into two hemispheres. Normally, the forebrain is formed and the face begins to develop in the fifth and sixth weeks of human pregnancy...

  • Homeo-box
  • Homeo-domain
  • Homeobox
    A homeobox is a DNA sequence found within genes that are involved in the regulation of patterns of anatomical development in animals, fungi and plants.- Discovery :...

  • Homeosis
    Homeosis is the transformation of one body part into another, arising from mutation in or misexpression of specific developmentally critical genes. It may be caused by mutations in Hox genes, found in animals, or others such as the MADS-box family in plants...

  • Homogametic sex
  • Homolog
    Homology (biology)
    Homology forms the basis of organization for comparative biology. In 1843, Richard Owen defined homology as "the same organ in different animals under every variety of form and function". Organs as different as a bat's wing, a seal's flipper, a cat's paw and a human hand have a common underlying...

  • Homologue
    Homology (biology)
    Homology forms the basis of organization for comparative biology. In 1843, Richard Owen defined homology as "the same organ in different animals under every variety of form and function". Organs as different as a bat's wing, a seal's flipper, a cat's paw and a human hand have a common underlying...

  • Homology
    Homology (biology)
    Homology forms the basis of organization for comparative biology. In 1843, Richard Owen defined homology as "the same organ in different animals under every variety of form and function". Organs as different as a bat's wing, a seal's flipper, a cat's paw and a human hand have a common underlying...

  • Homoplasmy
    Homoplasmy is the presence of a mutation affecting all of the mitochondrial DNA copies in a mammalian cell or chloroplast DNA in a plant cell. However, when a mutation occurs, it only affects some of the mitochondria, but not all of them known as heteroplasmy...

  • Homothallic
    Homothallic refers to the possession, within a single organism, of the resources to reproduce sexually.It can be contrasted to heterothallic.It is often used to categorize fungi. In yeast, heterothallic cells have mating types a and α...

  • Homothallic fungus
  • Homozygote
  • Homozygous
  • Homozygous gene pair
  • Hormone
    A hormone is a chemical released by a cell or a gland in one part of the body that sends out messages that affect cells in other parts of the organism. Only a small amount of hormone is required to alter cell metabolism. In essence, it is a chemical messenger that transports a signal from one...

  • Host range
  • Hot spot
    Recombination hotspot
    Recombination hotspots are small regions in the genome of sexually reproducing organisms that exhibit highly elevated rates of meiotic recombination. The peak recombination rate within hotspots can be hundreds or thousands of times that of the surrounding region. The PRDM9 protein is suspected to...

  • Housekeeping gene
    Housekeeping gene
    A housekeeping gene is typically a constitutive gene that is required for the maintenance of basic cellular function, and are found in all cells of an organism. Although some housekeeping genes are expressed at relatively constant levels , other housekeeping genes may vary depending on...

  • HUGO
    Human Genome Organisation
    The Human Genome Organisation is an organization involved in the Human Genome Project, a project about mapping the human genome. HUGO was established in 1989 as an international organization, primarily to foster collaboration between genome scientists around the world...

  • Human gene therapy
  • Human genetics
    Human genetics
    Human genetics describes the study of inheritance as it occurs in human beings. Human genetics encompasses a variety of overlapping fields including: classical genetics, cytogenetics, molecular genetics, biochemical genetics, genomics, population genetics, developmental genetics, clinical genetics,...

  • Human genome
    Human genome
    The human genome is the genome of Homo sapiens, which is stored on 23 chromosome pairs plus the small mitochondrial DNA. 22 of the 23 chromosomes are autosomal chromosome pairs, while the remaining pair is sex-determining...

  • Human Genome Project
    Human Genome Project
    The Human Genome Project is an international scientific research project with a primary goal of determining the sequence of chemical base pairs which make up DNA, and of identifying and mapping the approximately 20,000–25,000 genes of the human genome from both a physical and functional...

  • Huntington's disease
    Huntington's disease
    Huntington's disease, chorea, or disorder , is a neurodegenerative genetic disorder that affects muscle coordination and leads to cognitive decline and dementia. It typically becomes noticeable in middle age. HD is the most common genetic cause of abnormal involuntary writhing movements called chorea...

  • Hybrid (biology)
  • Hybrid DNA
  • Hybrid dysgenesis
  • Hybrid plasmid
  • Hybrid zone
    Hybrid zone
    A hybrid zone exists where the ranges of two interbreeding species meet. For a hybrid zone to be stable, the offspring produced by the cross have to be less fit than members of the parent species, although this condition does not need to be met in the very first hybrid generation...

  • Hybridoma
    Hybridoma technology is a technology of forming hybrid cell lines by fusing a specific antibody-producing B cell with a myeloma cell that is selected for its ability to grow in tissue culture and for an absence of antibody chain synthesis...

  • Hydrogen bond
    Hydrogen bond
    A hydrogen bond is the attractive interaction of a hydrogen atom with an electronegative atom, such as nitrogen, oxygen or fluorine, that comes from another molecule or chemical group. The hydrogen must be covalently bonded to another electronegative atom to create the bond...

  • Hydroxyapatite
  • Hypermorph
  • Hyperploid
  • Hypervariable locus
  • Hypervariable region
    Hypervariable region
    A hypervariable region is a location within nuclear DNA or the D-loop of mitochondrial DNA in which base pairs of nucleotides repeat or have substitutions...

  • Hypomorph
  • Hypoploid
  • Hypostatic gene
    Hypostatic gene
    A hypostatic gene is one whose phenotype is masked by the expression of an allele at a separate locus, in an epistasis event.Example: In labrador retrievers, the chocolate coat colour is a result of homozygosity for a gene that is epistatic to the "black vs. yellow" gene...


  • Ichthyosis
    Ichthyosis is a heterogeneous family of at least 28, generalized, mostly genetic skin disorders. All types of ichthyosis have dry, thickened, scaly or flaky skin...

  • Identical twin
  • Identity by descent
    Identity by descent
    Two or more alleles are identical by descent if they are identical copies of the same ancestral allele. This property is often used in genetic linkage to identify alleles which are potential candidates for harboring mutations causing a genetic disease....

  • Identity by type
    Identity by type
    Alleles have identity by type when they have the same phenotypic effect, or if applied to a variation in the composition of DNA such as a Single nucleotide polymorphism when they have the same DNA sequence....

  • Idiogram
  • Idiotypic variation
  • Idling reaction
  • Ile
    Isoleucine is an α-amino acid with the chemical formula HO2CCHCHCH2CH3. It is an essential amino acid, which means that humans cannot synthesize it, so it must be ingested. Its codons are AUU, AUC and AUA....

  • Imago
    In biology, the imago is the last stage of development of an insect, after the last ecdysis of an incomplete metamorphosis, or after emergence from the pupa where the metamorphosis is complete...

  • Immune system
    Immune system
    An immune system is a system of biological structures and processes within an organism that protects against disease by identifying and killing pathogens and tumor cells. It detects a wide variety of agents, from viruses to parasitic worms, and needs to distinguish them from the organism's own...

  • immunity
    Immunity (medical)
    Immunity is a biological term that describes a state of having sufficient biological defenses to avoid infection, disease, or other unwanted biological invasion. Immunity involves both specific and non-specific components. The non-specific components act either as barriers or as eliminators of wide...

  • Immunoglobulin (Ig)
  • Immunoglobulin gene
  • Immunohistochemistry
    Immunohistochemistry or IHC refers to the process of detecting antigens in cells of a tissue section by exploiting the principle of antibodies binding specifically to antigens in biological tissues. IHC takes its name from the roots "immuno," in reference to antibodies used in the procedure, and...

  • Immunotherapy
    Immunotherapy is a medical term defined as the "treatment of disease by inducing, enhancing, or suppressing an immune response". Immunotherapies designed to elicit or amplify an immune response are classified as activation immunotherapies. While immunotherapies that reduce or suppress are...

  • Imprinting
  • Indigenous Amerindian genetics
    Indigenous Amerindian genetics
    Genetic history of indigenous peoples of the Americas primarily focus on Human Y-chromosome DNA haplogroups and Human mitochondrial DNA haplogroups. Autosomal "atDNA" markers are also used, but differ from mtDNA or Y-DNA in that they overlap significantly...

  • In situ
    In situ
    In situ is a Latin phrase which translated literally as 'In position'. It is used in many different contexts.-Aerospace:In the aerospace industry, equipment on board aircraft must be tested in situ, or in place, to confirm everything functions properly as a system. Individually, each piece may...

  • Introduction to genetics
    Introduction to genetics
    Genetics is the study of genes, and tries to explain what they are and how they work. Genes are how living organisms inherit features from their ancestors; for example, children usually look like their parents because they have inherited their parents' genes...

  • In vitro
    In vitro
    In vitro refers to studies in experimental biology that are conducted using components of an organism that have been isolated from their usual biological context in order to permit a more detailed or more convenient analysis than can be done with whole organisms. Colloquially, these experiments...

  • In vitro mutagenesis
  • In vivo
    In vivo
    In vivo is experimentation using a whole, living organism as opposed to a partial or dead organism, or an in vitro controlled environment. Animal testing and clinical trials are two forms of in vivo research...

  • Inbreeding
    Inbreeding is the reproduction from the mating of two genetically related parents. Inbreeding results in increased homozygosity, which can increase the chances of offspring being affected by recessive or deleterious traits. This generally leads to a decreased fitness of a population, which is...

  • Incestuous
  • Inclusive fitness
    Inclusive fitness
    In evolutionary biology and evolutionary psychology, the inclusive fitness of an organism is the sum of its classical fitness and the number of equivalents of its own offspring it can add to the population by supporting others...

  • Incomplete dominance
  • Inducer
    In molecular biology, an inducer is a molecule that starts gene expression.For a gene to be expressed, its DNA sequence must be copied to make a smaller, mobile molecule called messenger RNA , which carries the instructions for making a protein to the site where the protein is manufactured...

  • Inducible operon
  • Induction
    Regulation of gene expression
    Gene modulation redirects here. For information on therapeutic regulation of gene expression, see therapeutic gene modulation.Regulation of gene expression includes the processes that cells and viruses use to regulate the way that the information in genes is turned into gene products...

  • Industrial melanism
  • Infectious transfer
  • Informed consent
    Informed consent
    Informed consent is a phrase often used in law to indicate that the consent a person gives meets certain minimum standards. As a literal matter, in the absence of fraud, it is redundant. An informed consent can be said to have been given based upon a clear appreciation and understanding of the...

  • Inherit
    Heredity is the passing of traits to offspring . This is the process by which an offspring cell or organism acquires or becomes predisposed to the characteristics of its parent cell or organism. Through heredity, variations exhibited by individuals can accumulate and cause some species to evolve...

  • Inherited
    Heredity is the passing of traits to offspring . This is the process by which an offspring cell or organism acquires or becomes predisposed to the characteristics of its parent cell or organism. Through heredity, variations exhibited by individuals can accumulate and cause some species to evolve...

  • Initiation codon
  • Initiation complex
  • Initiator protein
  • Inosine
    Inosine is a nucleoside that is formed when hypoxanthine is attached to a ribose ring via a β-N9-glycosidic bond....

  • Insertion
    Insertion (genetics)
    In genetics, an insertion is the addition of one or more nucleotide base pairs into a DNA sequence. This can often happen in microsatellite regions due to the DNA polymerase slipping...

  • Insertional mutation
  • Inside marker
  • Intercalating agent
  • Interference
  • Interkinesis
    Interkinesis or interphase II is a period of rest that cells enter during meiosis. It is the abbreviated interphase that occurs between meiosis I and II. No DNA replication occurs during this stage of meiosis. Many plants skip telophase I and interkinesis, going immediately into prophase II. Each...

  • Interphase
    Interphase is the phase of the cell cycle in which the cell spends the majority of its time and performs the majority of its purposes including preparation for cell division. In preparation for cell division, it increases its size and makes a copy of its DNA...

  • Interrupted mating
  • Intersex
    Intersex, in humans and other animals, is the presence of intermediate or atypical combinations of physical features that usually distinguish female from male...

  • Interstitial region
  • Intron
    An intron is any nucleotide sequence within a gene that is removed by RNA splicing to generate the final mature RNA product of a gene. The term intron refers to both the DNA sequence within a gene, and the corresponding sequence in RNA transcripts. Sequences that are joined together in the final...

  • Introns
  • Inversion
    Chromosomal inversion
    An inversion is a chromosome rearrangement in which a segment of a chromosome is reversed end to end. An inversion occurs when a single chromosome undergoes breakage and rearrangement within itself. Inversions are of two types: paracentric and pericentric.Paracentric inversions do not include the...

  • Iojap
  • Ionizing radiation
    Ionizing radiation
    Ionizing radiation is radiation composed of particles that individually have sufficient energy to remove an electron from an atom or molecule. This ionization produces free radicals, which are atoms or molecules containing unpaired electrons...

  • IR
    Inverted repeat
    An inverted repeat is a sequence of nucleotides that is the reversed complement of another sequence further downstream.For example, 5'---GACTGC....GCAGTC---3'. When no nucleotides intervene between the sequence and its downstream complement, it is called a palindrome. Inverted repeats define the...

  • IS
    Insertion sequence
    An insertion sequence is a short DNA sequence that acts as a simple transposable element...

  • IS element
  • Isoaccepting tRNA
  • Isochromosome
    An isochromosome is a chromosome that has lost one of its arms and replaced it with an exact copy of the other arm. This is sometimes seen in some females with Turner syndrome or in tumor cells. This may also cause an isochromosome to have two centromeres The chromosome arm is already copied during...

  • Isoenzyme
  • Isoschizomer
    Isoschizomers are pairs of restriction enzymes specific to the same recognition sequence. For example, Sph I and Bbu I are isoschizomers of each other. The first enzyme to recognize and cut a given sequence is known as the prototype, all subsequent enzymes that recognize and cut that sequence...

  • Isotope
    Isotopes are variants of atoms of a particular chemical element, which have differing numbers of neutrons. Atoms of a particular element by definition must contain the same number of protons but may have a distinct number of neutrons which differs from atom to atom, without changing the designation...

  • Isozyme
    Isozymes are enzymes that differ in amino acid sequence but catalyze the same chemical reaction. These enzymes usually display different kinetic parameters Isozymes (also known as isoenzymes) are enzymes that differ in amino acid sequence but catalyze the same chemical reaction. These enzymes...


  • Kappa particle
  • Kartagener's syndrome
  • Karyokinesis
  • Karyotype
    A karyotype is the number and appearance of chromosomes in the nucleus of an eukaryotic cell. The term is also used for the complete set of chromosomes in a species, or an individual organism.p28...

  • Kilobase
  • Kin selection
    Kin selection
    Kin selection refers to apparent strategies in evolution that favor the reproductive success of an organism's relatives, even at a cost to the organism's own survival and reproduction. Charles Darwin was the first to discuss the concept of group/kin selection...

  • Kinetochore
    The kinetochore is the protein structure on chromatids where the spindle fibers attach during cell division to pull sister chromatids apart....

  • Klinefelter syndrome
  • Knockout
    A knockout is a fight-ending, winning criterion in several full-contact combat sports, such as boxing, kickboxing, Muay Thai, mixed martial arts, Karate and others sports involving striking...


  • Lac operon
    Lac operon
    The lac operon is an operon required for the transport and metabolism of lactose in Escherichia coli and some other enteric bacteria. It consists of three adjacent structural genes, lacZ, lacY and lacA. The lac operon is regulated by several factors including the availability of glucose and of...

  • Lagging strand
  • Lambda dgal
  • Lambda phage
    Lambda phage
    Enterobacteria phage λ is a temperate bacteriophage that infects Escherichia coli.Lambda phage is a virus particle consisting of a head, containing double-stranded linear DNA as its genetic material, and a tail that can have tail fibers. The phage particle recognizes and binds to its host, E...

  • Lateral inhibition
    Lateral inhibition
    In neurobiology, lateral inhibition is the capacity of an excited neuron to reduce the activity of its neighbors. Lateral inhibition sharpens the spatial profile of excitation in response to a localized stimulus.-Sensory inhibition:...

  • Lawn
    A lawn is an area of aesthetic and recreational land planted with grasses or other durable plants, which usually are maintained at a low and consistent height. Low ornamental meadows in natural landscaping styles are a contemporary option of a lawn...

  • Leader peptide gene
  • Leader sequence
  • Leader transcript
  • Leading strand
  • Leaky mutant
  • Lesion
    A lesion is any abnormality in the tissue of an organism , usually caused by disease or trauma. Lesion is derived from the Latin word laesio which means injury.- Types :...

  • Lethal gene
  • Leu
    Leucine is a branched-chain α-amino acid with the chemical formula HO2CCHCH2CH2. Leucine is classified as a hydrophobic amino acid due to its aliphatic isobutyl side chain. It is encoded by six codons and is a major component of the subunits in ferritin, astacin and other 'buffer' proteins...

  • Leucine zipper
    Leucine zipper
    A leucine zipper, aka leucine scissors, is a common three-dimensional structural motif in proteins. These motifs are usually found as part of a DNA-binding domain in various transcription factors, and are therefore involved in regulating gene expression...

  • Leukemia
    Leukemia or leukaemia is a type of cancer of the blood or bone marrow characterized by an abnormal increase of immature white blood cells called "blasts". Leukemia is a broad term covering a spectrum of diseases...

  • Li-Fraumeni syndrome
    Li-Fraumeni syndrome
    Li-Fraumeni syndrome is an extremely rare autosomal dominant hereditary disorder. It is named after Frederick Pei Li and Joseph F. Fraumeni, Jr., the American physicians who first recognized and described the syndrome. Li-Fraumeni syndrome greatly increases susceptibility to cancer...

  • Library (genetics)
  • Ligase
    In biochemistry, ligase is an enzyme that can catalyse the joining of two large molecules by forming a new chemical bond, usually with accompanying hydrolysis of a small chemical group dependent to one of the larger molecules...

  • Line
  • Linear tetrad
  • Linkage
    Genetic linkage
    Genetic linkage is the tendency of certain loci or alleles to be inherited together. Genetic loci that are physically close to one another on the same chromosome tend to stay together during meiosis, and are thus genetically linked.-Background:...

  • Linkage analysis
  • Linkage equilibrium
  • Linkage group
  • Linkage map
  • Linking number
    Linking number
    In mathematics, the linking number is a numerical invariant that describes the linking of two closed curves in three-dimensional space. Intuitively, the linking number represents the number of times that each curve winds around the other...

  • Localize
  • Locus
    Locus (genetics)
    In the fields of genetics and genetic computation, a locus is the specific location of a gene or DNA sequence on a chromosome. A variant of the DNA sequence at a given locus is called an allele. The ordered list of loci known for a particular genome is called a genetic map...

  • Lod score
  • Lod score method
  • Lymphocyte
    A lymphocyte is a type of white blood cell in the vertebrate immune system.Under the microscope, lymphocytes can be divided into large lymphocytes and small lymphocytes. Large granular lymphocytes include natural killer cells...

  • Lymphoma
    Lymphoma is a cancer in the lymphatic cells of the immune system. Typically, lymphomas present as a solid tumor of lymphoid cells. Treatment might involve chemotherapy and in some cases radiotherapy and/or bone marrow transplantation, and can be curable depending on the histology, type, and stage...

  • Lyon hypothesis
  • Lys
    Lysine is an α-amino acid with the chemical formula HO2CCH4NH2. It is an essential amino acid, which means that the human body cannot synthesize it. Its codons are AAA and AAG....

  • Lysate
  • Lysis
    Lysis refers to the breaking down of a cell, often by viral, enzymic, or osmotic mechanisms that compromise its integrity. A fluid containing the contents of lysed cells is called a "lysate"....

  • Lysogen
    A lysogen or lysogenic phage is a phage that can exist as a prophage within its host organism. A prophage is the phage DNA in its dormant state, and is either integrated into the host bacteria's chromosome or more rarely exists as a stable plasmid within the host cell...

  • Lysogenic
  • Lysogenic bacterium


  • Macromolecule
    A macromolecule is a very large molecule commonly created by some form of polymerization. In biochemistry, the term is applied to the four conventional biopolymers , as well as non-polymeric molecules with large molecular mass such as macrocycles...

  • Macrorestriction map
  • Malformation
  • Manx
    Manx (cat)
    The Manx cat , formerly often spelled Manks, is a breed of domestic cat originating on the Isle of Man, with a naturally occurring mutation that shortens the tail...

  • Mapping
    Gene mapping
    Gene mapping, also called genome mapping, is the creation of a genetic map assigning DNA fragments to chromosomes.When a genome is first investigated, this map is nonexistent. The map improves with the scientific progress and is perfect when the genomic DNA sequencing of the species has been...

  • Mapping function
  • Mapping population
  • Marfan syndrome
    Marfan syndrome
    Marfan syndrome is a genetic disorder of the connective tissue. People with Marfan's tend to be unusually tall, with long limbs and long, thin fingers....

  • Marker
    Genetic marker
    A genetic marker is a gene or DNA sequence with a known location on a chromosome that can be used to identify cells, individuals or species. It can be described as a variation that can be observed...

  • Marker retention
  • Mass spectrometry
    Mass spectrometry
    Mass spectrometry is an analytical technique that measures the mass-to-charge ratio of charged particles.It is used for determining masses of particles, for determining the elemental composition of a sample or molecule, and for elucidating the chemical structures of molecules, such as peptides and...

  • Mate-killer
  • Maternal effect
    Maternal effect
    A maternal effect is a situation where the phenotype of an organism is determined not only by the environment it experiences and its genotype, but also by the environment and phenotype of its mother...

  • Maternal inheritance
  • Mating type
    Mating type
    Mating types occur in eukaryotes that undergo sexual reproduction via isogamy. Since the gametes of different mating types look alike, they are often referred to by numbers, letters, or simply "+" and "-" instead of "male" and "female." Mating can only take place between different mating...

  • Mean
    In statistics, mean has two related meanings:* the arithmetic mean .* the expected value of a random variable, which is also called the population mean....

  • Medium
    Growth medium
    A growth medium or culture medium is a liquid or gel designed to support the growth of microorganisms or cells, or small plants like the moss Physcomitrella patens.There are different types of media for growing different types of cells....

  • Megabase
  • Meiocyte
    A meiocyte is a cell which is an immediate precursor to a gamete. It is so named because meiosis occurs in the cell. A meiocyte goes through meiosis to form a tetrad. This tetrad consists of 4 genetically different cells that have half the genetic information of the meiocyte from which it came....

  • Meiosis
    Meiosis is a special type of cell division necessary for sexual reproduction. The cells produced by meiosis are gametes or spores. The animals' gametes are called sperm and egg cells....

  • Meiospore
  • Melanoma
    Melanoma is a malignant tumor of melanocytes. Melanocytes are cells that produce the dark pigment, melanin, which is responsible for the color of skin. They predominantly occur in skin, but are also found in other parts of the body, including the bowel and the eye...

  • Melting of DNA
  • Mendel's first law
  • Mendel's second law
  • Mendelian ratio
  • Merozygote
    Merozygote is a state when a cell, usually bacterial, is temporarily diploid as result of DNA transfer processes like conjugation.One example of how merozygotes can be formed is the transfer of genetic material...

  • Messenger RNA
    Messenger RNA
    Messenger RNA is a molecule of RNA encoding a chemical "blueprint" for a protein product. mRNA is transcribed from a DNA template, and carries coding information to the sites of protein synthesis: the ribosomes. Here, the nucleic acid polymer is translated into a polymer of amino acids: a protein...

  • Met
    -In the arts:* Metropolitan Opera in Manhattan, New York* Metropolitan Museum of Art in Manhattan, New York* Various buildings known as the Metropolitan Opera House* The Metropolitan Ensemble Theater in Kansas City, Missouri-In computing and the Internet:...

  • Metabolism
    Metabolism is the set of chemical reactions that happen in the cells of living organisms to sustain life. These processes allow organisms to grow and reproduce, maintain their structures, and respond to their environments. Metabolism is usually divided into two categories...

  • Metafemale
  • Metagon
  • Metamale
  • Metamere
    In chemistry, isomers are compounds with the same molecular formula but different structural formulas. Isomers do not necessarily share similar properties, unless they also have the same functional groups. There are many different classes of isomers, like stereoisomers, enantiomers, geometrical...

  • Metaphase
    Metaphase, from the ancient Greek μετά and φάσις , is a stage of mitosis in the eukaryotic cell cycle in which condensed & highly coiled chromosomes, carrying genetic information, align in the middle of the cell before being separated into each of the two daughter cells...

  • Metaphase plate
  • Metastasis
    Metastasis, or metastatic disease , is the spread of a disease from one organ or part to another non-adjacent organ or part. It was previously thought that only malignant tumor cells and infections have the capacity to metastasize; however, this is being reconsidered due to new research...

  • Methylation
    In the chemical sciences, methylation denotes the addition of a methyl group to a substrate or the substitution of an atom or group by a methyl group. Methylation is a form of alkylation with, to be specific, a methyl group, rather than a larger carbon chain, replacing a hydrogen atom...

  • Metrical variation
  • Microarray
    A microarray is a multiplex lab-on-a-chip. It is a 2D array on a solid substrate that assays large amounts of biological material using high-throughput screening methods.Types of microarrays include:...

  • Microbial genetics
    Microbial genetics
    Microbial genetics is a subject area within microbiology and genetic engineering. It studies the genetics of very small organisms. This involves the study of the genotype of microbial species and also the expression system in the form of phenotypes.It also involves the study of genetic processes...

  • Microinjection
    Microinjection refers to the process of using a glass micropipette to insert substances at a microscopic or borderline macroscopic level into a single living cell. It is a simple mechanical process in which a needle roughly 0.5 to 5 micrometers in diameter penetrates the cell membrane and/or the...

  • Micronuclei
  • Microsatellite
  • Microtubules
  • Midparent value
  • Migration
  • Mimicry
  • Minimal medium
  • Mismatch repair
  • Missense mutation
    Missense mutation
    In genetics, a missense mutation is a point mutation in which a single nucleotide is changed, resulting in a codon that codes for a different amino acid . This can render the resulting protein nonfunctional...

  • Mitochondrial DNA
    Mitochondrial DNA
    Mitochondrial DNA is the DNA located in organelles called mitochondria, structures within eukaryotic cells that convert the chemical energy from food into a form that cells can use, adenosine triphosphate...

  • Mitochondrial Eve
    Mitochondrial Eve
    In the field of human genetics, Mitochondrial Eve refers to the matrilineal "MRCA" . In other words, she was the woman from whom all living humans today descend, on their mother's side, and through the mothers of those mothers and so on, back until all lines converge on one person...

  • Human mitochondrial genetics
    Human mitochondrial genetics
    Human mitochondrial genetics is the study of the genetics of the DNA contained in human mitochondria. Mitochondria are small structures in cells that generate energy for the cell to use, and are hence referred to as the "powerhouses" of the cell....

  • Mitochondrion
    In cell biology, a mitochondrion is a membrane-enclosed organelle found in most eukaryotic cells. These organelles range from 0.5 to 1.0 micrometers in diameter...

  • Mitosis
    Mitosis is the process by which a eukaryotic cell separates the chromosomes in its cell nucleus into two identical sets, in two separate nuclei. It is generally followed immediately by cytokinesis, which divides the nuclei, cytoplasm, organelles and cell membrane into two cells containing roughly...

  • Mitotic apparatus
  • Mitotic crossover
    Mitotic crossover
    Mitotic crossover is a rare type of genetic recombination that may occur in some types of somatic cells during mitosis. Mitotic crossover may occur in organisms that do not have a cycle of sexual reproduction where chromosomal crossover would normally occur during meiosis to generate genetic...

  • Mixed codon family
  • Mode
    Mode (statistics)
    In statistics, the mode is the value that occurs most frequently in a data set or a probability distribution. In some fields, notably education, sample data are often called scores, and the sample mode is known as the modal score....

  • Model organisms
  • Modeling
  • Modifier gene
  • Molecular biology
    Molecular biology
    Molecular biology is the branch of biology that deals with the molecular basis of biological activity. This field overlaps with other areas of biology and chemistry, particularly genetics and biochemistry...

  • Molecular chaperone
  • Molecular farming
    Molecular farming
    Molecular farming is the use of genetically engineered crops to produce compounds with therapeutic value. These crops will become biological factories used to generate drugs and other difficult or expensive products...

  • Molecular genetics
    Molecular genetics
    Molecular genetics is the field of biology and genetics that studies the structure and function of genes at a molecular level. The field studies how the genes are transferred from generation to generation. Molecular genetics employs the methods of genetics and molecular biology...

  • Molecular imprinting
    Molecular imprinting
    In chemistry, molecular imprinting is a technique to create template-shaped cavities in polymer matrices with memory of the template molecules to be used in molecular recognition . This technique is based on the system used by enzymes for substrate recognition, which is called the "lock and key"...

  • Molecular medicine
    Molecular medicine
    Molecular medicine is a broad field, where physical, chemical, biological and medical techniques are used to describe molecular structures and mechanisms, identify fundamental molecular and genetic errors of disease, and to develop molecular interventions to correct them...

  • Molecule
    A molecule is an electrically neutral group of at least two atoms held together by covalent chemical bonds. Molecules are distinguished from ions by their electrical charge...

  • Monocistronic mRNA
  • Monoclonal antibody
  • Monoecious plant
  • Monogenic disorder
  • Monohybrid
  • Monohybrid cross
    Monohybrid cross
    Monohybrid Cross is a method of determining the inheritance pattern of a trait between two single organisms. A monohybrid cross is a cross between parents who are heterozygous at one locus; for example, Bb x Bb . Example: B = brown. b = blue. BB = Dark Brown. Bb = Brown . bb = Blue.Monohybrid...

  • Monoploid
  • Monosomic
  • Monosomy
    Monosomy is a form of aneuploidy with the presence of only one chromosome from a pair. Partial monosomy occurs when only a portion of the chromosome has one copy, while the rest has two copies.-Human monosomy:...

  • Morbid map
    Morbid map
    In genetics, a morbid map is a chart or diagram of diseases and the chromosomal location of genes the diseases are associated with....

  • Morphogenesis
    Morphogenesis , is the biological process that causes an organism to develop its shape...

  • Mosaic (genetics)
    Mosaic (genetics)
    In genetic medicine, a mosaic or mosaicism denotes the presence of two populations of cells with different genotypes in one individual who has developed from a single fertilized egg...

  • Mosaicism
  • Mouse model
  • mRNA
  • mtDNA
  • Mu particle
  • Mu phage
    Mu phage
    Bacteriophage Mu or phage Mu is a temperate bacteriophage, a type of virus that infects bacteria.-Replication:It uses DNA-based transposition to integrate its genome into the genome of the host cell that it is infecting. It can then use transposition to initiate its viral DNA replication...

  • Mullerian mimicry
    Müllerian mimicry
    Müllerian mimicry is a natural phenomenon when two or more harmful species, that may or may not be closely related and share one or more common predators, have come to mimic each other's warning signals...

  • Multifactorial
  • Multihybrid
  • Multimeric structure
  • Multiple allelism
  • Multiplexing
    The multiplexed signal is transmitted over a communication channel, which may be a physical transmission medium. The multiplexing divides the capacity of the low-level communication channel into several higher-level logical channels, one for each message signal or data stream to be transferred...

  • Murine
  • Mutability
  • Mutagen
    In genetics, a mutagen is a physical or chemical agent that changes the genetic material, usually DNA, of an organism and thus increases the frequency of mutations above the natural background level. As many mutations cause cancer, mutagens are therefore also likely to be carcinogens...

  • Mutagenicity
  • Mutant
    In biology and especially genetics, a mutant is an individual, organism, or new genetic character, arising or resulting from an instance of mutation, which is a base-pair sequence change within the DNA of a gene or chromosome of an organism resulting in the creation of a new character or trait not...

  • Mutant allele
  • Mutant screening
  • Mutant site
  • Mutation
    In molecular biology and genetics, mutations are changes in a genomic sequence: the DNA sequence of a cell's genome or the DNA or RNA sequence of a virus. They can be defined as sudden and spontaneous changes in the cell. Mutations are caused by radiation, viruses, transposons and mutagenic...

  • Mutation breeding
    Mutation breeding
    Mutation breeding is the process of exposing seeds to chemicals or radiation in order to generate mutants with desirable traits to be bred with other cultivars. Plants created using mutagenesis are sometimes called mutagenic plants or mutagenic seeds...

  • Mutation event
  • Mutation frequency
    Mutation frequency
    Mutation frequency refers to the number or "frequency" of cells with a specific mutation in a given population during a point in time. The phrase is often used in relation to drug resistance in bacterial or viral cultures....

  • Mutation rate
    Mutation rate
    In genetics, the mutation rate is the chance of a mutation occurring in an organism or gene in each generation...

  • Mutational load
  • Mutator mutation
  • Muton
  • Myeloma
  • Myotonic dystrophy
    Myotonic dystrophy
    Myotonic dystrophy is a chronic, slowly progressing, highly variable inherited multisystemic disease. It is characterized by wasting of the muscles , cataracts, heart conduction defects, endocrine changes, and myotonia. Myotonic dystrophy can occur in patients of any age...


  • N segment
  • N-end rule
    N-end rule
    The N-end rule is a rule related to ubiquitination, discovered by Alexander Varshavsky in 1986. The rule, which states that the nature of the N-terminal amino acids of a protein is an important factor that governs its half-life , is applicable to both eukaryotic and prokaryotic organisms, but with...

  • Narrow heritability
  • Natural selection
    Natural selection
    Natural selection is the nonrandom process by which biologic traits become either more or less common in a population as a function of differential reproduction of their bearers. It is a key mechanism of evolution....

  • Negative control
  • Neo-darwinism
    Neo-Darwinism is the 'modern synthesis' of Darwinian evolution through natural selection with Mendelian genetics, the latter being a set of primary tenets specifying that evolution involves the transmission of characteristics from parent to child through the mechanism of genetic transfer, rather...

  • Neomorph
  • Neoplasm
  • Neurofibromatosis
    Neurofibromatosis is a genetically-inherited disorder in which the nerve tissue grows tumors that may be benign or may cause serious damage by compressing nerves and other tissues...

  • Neurospora
    Neurospora is a genus of Ascomycete fungi. The genus name, meaning "nerve spore" refers to the characteristic striations on the spores that resemble axons....

  • Neutral mutation
    Neutral mutation
    In genetics, a neutral mutation is a mutation that has no effect on fitness. In other words, it is neutral with respect to natural selection.For example, some mutations in a DNA triplet or codon do not change which amino acid is introduced: this is known as a synonymous substitution. Unless the...

  • Neutral petite
  • Newborn screening
    Newborn screening
    Newborn screening is the process by which infants are screened shortly after birth for a list of disorders that are treatable, but difficult or impossible to detect clinically. Screening programs are often run by state or national governing bodies with the goal of screening all infants born in the...

  • NF
    Neurofibromatosis is a genetically-inherited disorder in which the nerve tissue grows tumors that may be benign or may cause serious damage by compressing nerves and other tissues...

  • Nickase
  • Nicking
  • NIH
  • Nitrogen base
  • Nitrogenous base
    Nitrogenous base
    A nitrogenous base is a nitrogen-containing molecule having the chemical properties of a base. It is an organic compound that owes its property as a base to the lone pair of electrons of a nitrogen atom. In biological sciences, nitrogenous bases are typically classified as the derivatives of two...

  • Non-coding DNA
  • Non-coding strand
  • Non-directiveness
  • Non-disjunction
    Nondisjunction is the failure of chromosome pairs to separate properly during meiosis stage 1 or stage 2. This could arise from a failure of homologous chromosomes to separate in meiosis I, or the failure of sister chromatids to separate during meiosis II or mitosis. The result of this error is a...

  • Non-histone protein
    Non-histone protein
    In chromatin, those proteins which remain after the histones have been removed, are classified as non-histone proteins. Scaffold proteins, DNA polymerase, Heterochromatin Protein 1 and Polycomb are common non-histone proteins. This classification group also includes numerous other structural,...

  • Non-linear tetrad
  • Non-Mendelian ratio
  • Non-parental
  • Non-recombinant
  • Nonsense codon
  • Nonsense mutation
    Nonsense mutation
    In genetics, a nonsense mutation is a point mutation in a sequence of DNA that results in a premature stop codon, or a nonsense codon in the transcribed mRNA, and in a truncated, incomplete, and usually nonfunctional protein product. It differs from a missense mutation, which is a point mutation...

  • Nonsense suppressor
    Nonsense suppressor
    A nonsense suppressor is a tRNA mutation that suppresses the protein truncation resulting from a nonsense mutation.The nonsense suppressor is a tRNA gene which has a mutated anticodon....

  • Noonan syndrome
    Noonan syndrome
    Noonan Syndrome is a relatively common autosomal dominant congenital disorder considered to be a type of dwarfism, that affects both males and females equally. It used to be referred to as the male version of Turner's syndrome ; however, the genetic causes of Noonan syndrome and Turner syndrome...

  • Norm of reaction
  • Normal distribution
  • Northern analysis
  • Northern blot
    Northern blot
    The northern blot is a technique used in molecular biology research to study gene expression by detection of RNA in a sample. With northern blotting it is possible to observe cellular control over structure and function by determining the particular gene expression levels during differentiation,...

  • NPD
    Tetrad (genetics)
    The tetrad is the four spores of a yeast or Chlamydomonas, that separate after mating. If the two parents have a mutation in two different genes, the tetrad can segregate as the parental ditype , the non-parental ditype or as the tetratype ....

  • Nu body
  • Nuclear transfer
    Nuclear transfer
    Nuclear Transfer is a form of cloning. The steps involve removing the DNA from an oocyte , and injecting the nucleus which contains the DNA to be cloned. In rare instances, the newly constructed cell will divide normally, replicating the new DNA while remaining in a pluripotent state...

  • Nuclease
    A nuclease is an enzyme capable of cleaving the phosphodiester bonds between the nucleotide subunits of nucleic acids. Older publications may use terms such as "polynucleotidase" or "nucleodepolymerase"....

  • Nucleic acid
    Nucleic acid
    Nucleic acids are biological molecules essential for life, and include DNA and RNA . Together with proteins, nucleic acids make up the most important macromolecules; each is found in abundance in all living things, where they function in encoding, transmitting and expressing genetic information...

  • Nucleoid
    The nucleoid is an irregularly-shaped region within the cell of a prokaryote that contains all or most of the genetic material. In contrast to the nucleus of a eukaryotic cell, it is not surrounded by a nuclear membrane. The genome of prokaryotic organisms generally is a circular, double-stranded...

  • Nucleolar organizer
  • Nucleolus
    The nucleolus is a non-membrane bound structure composed of proteins and nucleic acids found within the nucleus. Ribosomal RNA is transcribed and assembled within the nucleolus...

  • Nucleoprotein
    A nucleoprotein is any protein that is structurally associated with nucleic acid .Many viruses harness this protein, and they are known for being host-specific...

  • Nucleoside
    Nucleosides are glycosylamines consisting of a nucleobase bound to a ribose or deoxyribose sugar via a beta-glycosidic linkage...

  • Nucleosome
    Nucleosomes are the basic unit of DNA packaging in eukaryotes, consisting of a segment of DNA wound around a histone protein core. This structure is often compared to thread wrapped around a spool....

  • Nucleotide
    Nucleotides are molecules that, when joined together, make up the structural units of RNA and DNA. In addition, nucleotides participate in cellular signaling , and are incorporated into important cofactors of enzymatic reactions...

  • Nucleotide pair
  • Nucleotides
  • Nucleus
    Cell nucleus
    In cell biology, the nucleus is a membrane-enclosed organelle found in eukaryotic cells. It contains most of the cell's genetic material, organized as multiple long linear DNA molecules in complex with a large variety of proteins, such as histones, to form chromosomes. The genes within these...

  • Null allele
    Null allele
    A null allele is a mutant copy of a gene that completely lacks that gene's normal function. This can be the result of the complete absence of the gene product at the molecular level, or the expression of a non-functional gene product...

  • Null hypothesis
    Null hypothesis
    The practice of science involves formulating and testing hypotheses, assertions that are capable of being proven false using a test of observed data. The null hypothesis typically corresponds to a general or default position...

  • Nullisomic
    Nullisomic is a genetic condition involving the lack of one of the normal chromosomal pairs for a species . Humans with this condition will not survive....

  • Numerator element
  • Nurse cell
    Nurse cell
    -Human physiology:Nurse cells are specialized macrophages residing in the bone marrow that assist in the development of red blood cells. They absorb the nuclei of immature red blood cells and may provide growth factors to help the red blood cells mature...


  • Ochre codon
  • Octad
  • Okazaki fragment
    Okazaki fragment
    Okazaki fragments are short molecules of single-stranded DNA that are formed on the lagging strand during DNA replication. They are between 1,000 to 2,000 nucleotides long in Escherichia coli and are between 100 to 200 nucleotides long in eukaryotes....

  • Oligo
    An oligonucleotide is a short nucleic acid polymer, typically with fifty or fewer bases. Although they can be formed by bond cleavage of longer segments, they are now more commonly synthesized, in a sequence-specific manner, from individual nucleoside phosphoramidites...

  • Oligogenic
  • Oligonucleotide
    An oligonucleotide is a short nucleic acid polymer, typically with fifty or fewer bases. Although they can be formed by bond cleavage of longer segments, they are now more commonly synthesized, in a sequence-specific manner, from individual nucleoside phosphoramidites...

  • Oncogene
    An oncogene is a gene that has the potential to cause cancer. In tumor cells, they are often mutated or expressed at high levels.An oncogene is a gene found in the chromosomes of tumor cells whose activation is associated with the initial and continuing conversion of normal cells into cancer...

  • Oncogenes
  • Oncovirus
    An oncovirus is a virus that can cause cancer. This term originated from studies of acutely-transforming retroviruses in the 1950–60s, often called oncornaviruses to denote their RNA virus origin. It now refers to any virus with a DNA or RNA genome causing cancer and is synonymous with "tumor...

  • Oocyte
    An oocyte, ovocyte, or rarely ocyte, is a female gametocyte or germ cell involved in reproduction. In other words, it is an immature ovum, or egg cell. An oocyte is produced in the ovary during female gametogenesis. The female germ cells produce a primordial germ cell which undergoes a mitotic...

  • Oogenesis
    Oogenesis, ovogenesis or oögenesis is the creation of an ovum . It is the female form of gametogenesis. The male equivalent is spermatogenesis...

  • Oogonia
  • Opal codon
  • Open reading frame
    Open reading frame
    In molecular genetics, an open reading frame is a DNA sequence that does not contain a stop codon in a given reading frame.Normally, inserts which interrupt the reading frame of a subsequent region after the start codon cause frameshift mutation of the sequence and dislocate the sequences for stop...

  • Operator (biology)
    Operator (biology)
    In genetics, an operator is a segment of DNA to which a transcription factor protein binds. It is classically defined in the lac operon as a segment between the promoter and the genes of the operon. In the case of a repressor, the repressor protein physically obstructs the RNA polymerase from...

  • Operon
    In genetics, an operon is a functioning unit of genomic DNA containing a cluster of genes under the control of a single regulatory signal or promoter. The genes are transcribed together into an mRNA strand and either translated together in the cytoplasm, or undergo trans-splicing to create...

  • Organelle
    In cell biology, an organelle is a specialized subunit within a cell that has a specific function, and is usually separately enclosed within its own lipid bilayer....

  • Organogenesis
    In animal development, organogenesis is the process by which the ectoderm, endoderm, and mesoderm develop into the internal organs of the organism. Internal organs initiate development in humans within the 3rd to 8th weeks in utero...

  • Outbreeding
  • Outside markers
  • Overdominance
    Overdominance is a condition in genetics where the phenotype of the heterozygote lies outside of the phenotypical range of both homozygote parents. Overdominance can also be described as heterozygote advantage, wherein heterozygous individuals have a higher fitness than homozygous individuals.An...

  • Overlapping clones
  • Ovum
    An ovum is a haploid female reproductive cell or gamete. Both animals and embryophytes have ova. The term ovule is used for the young ovum of an animal, as well as the plant structure that carries the female gametophyte and egg cell and develops into a seed after fertilization...


  • P (peptidyl) site
  • P element
  • P1
    P1 nuclease
    P1 nuclease is a nuclease that works on single-stranded DNA as well as RNA. P1 nuclease cleaves at every position yielding nucleoside 5' monophosphates. It is useful at removing single stranded strands hanging off the end of double stranded DNA and at completely cleaving melted DNA for simple DNA...

  • P53
    p53 , is a tumor suppressor protein that in humans is encoded by the TP53 gene. p53 is crucial in multicellular organisms, where it regulates the cell cycle and, thus, functions as a tumor suppressor that is involved in preventing cancer...

  • Palindrome
    A palindrome is a word, phrase, number, or other sequence of units that can be read the same way in either direction, with general allowances for adjustments to punctuation and word dividers....

  • Panmictic
  • Paralogous genes
  • Paramecin
  • Parameter
    Parameter from Ancient Greek παρά also “para” meaning “beside, subsidiary” and μέτρον also “metron” meaning “measure”, can be interpreted in mathematics, logic, linguistics, environmental science and other disciplines....

  • Parental
  • Parental ditype
  • Parental imprinting
  • Parkinson's disease
    Parkinson's disease
    Parkinson's disease is a degenerative disorder of the central nervous system...

  • Parthenogenesis
    Parthenogenesis is a form of asexual reproduction found in females, where growth and development of embryos occur without fertilization by a male...

  • Partial digest
  • Partial diploid
  • Partial dominance
  • Pascal's triangle
    Pascal's triangle
    In mathematics, Pascal's triangle is a triangular array of the binomial coefficients in a triangle. It is named after the French mathematician, Blaise Pascal...

  • Patent
    A patent is a form of intellectual property. It consists of a set of exclusive rights granted by a sovereign state to an inventor or their assignee for a limited period of time in exchange for the public disclosure of an invention....

  • Path diagram
  • Pathogen
    A pathogen gignomai "I give birth to") or infectious agent — colloquially, a germ — is a microbe or microorganism such as a virus, bacterium, prion, or fungus that causes disease in its animal or plant host...

  • Pattern formation
    Pattern formation
    The science of pattern formation deals with the visible, orderly outcomes of self-organisation and the common principles behind similar patterns....

  • PCR
    Polymerase chain reaction
    The polymerase chain reaction is a scientific technique in molecular biology to amplify a single or a few copies of a piece of DNA across several orders of magnitude, generating thousands to millions of copies of a particular DNA sequence....

  • PD
    Programmed Death 1, or PD-1, is a Type I membrane protein of 268 amino acids. PD-1 is a member of the extended CD28/CTLA-4 family of T cell regulators. The protein's structure includes an extracellular IgV domain followed by a transmembrane region and an intracellular tail...

  • Pedigree
    Pedigree chart
    A pedigree chart is a diagram that shows the occurrence and appearance or phenotypes of a particular gene or organism and its ancestors from one generation to the next, most commonly humans, show dogs, and race horses....

  • Penetrance
    Penetrance in genetics is the proportion of individuals carrying a particular variant of a gene that also express an associated trait . In medical genetics, the penetrance of a disease-causing mutation is the proportion of individuals with the mutation who exhibit clinical symptoms...

  • Peptide
    Peptides are short polymers of amino acid monomers linked by peptide bonds. They are distinguished from proteins on the basis of size, typically containing less than 50 monomer units. The shortest peptides are dipeptides, consisting of two amino acids joined by a single peptide bond...

  • Peptide bond
    Peptide bond
    This article is about the peptide link found within biological molecules, such as proteins. A similar article for synthetic molecules is being created...

  • Peptidyl transferase
    Peptidyl transferase
    The Peptidyl transferase is an aminoacyltransferase as well as the primary enzymatic function of the ribosome, which forms peptide links between adjacent amino acids using tRNAs during the translation process of protein biosynthesis....

  • Permissive condition
  • PEST hypothesis
  • Petite mutation
    Petite mutation
    petite is a mutant first discovered in the yeast Saccharomyces cerevisiae. Due to defect in the respiratory chain, 'petite' yeast are unable to grow on media containing only non-fermentable carbon sources , and form small anaerobic colonies when grown in the presence of fermentable carbon sources...

  • Phage
  • Pharmacogenomics
    Pharmacogenomics is the branch of pharmacology which deals with the influence of genetic variation on drug response in patients by correlating gene expression or single-nucleotide polymorphisms with a drug's efficacy or toxicity...

  • Pharming (genetics)
    Pharming (genetics)
    Pharming is a portmanteau of farming and "pharmaceutical" and refers to the use of genetic engineering to insert genes that code for useful pharmaceuticals into host animals or plants that would otherwise not express those genes. As a consequence, the host animals or plants then make the...

  • Phe
    PHE may refer to:* Population Health and Environment , an approach to development that integrates health or family planning with conservation efforts* Paramount Home Entertainment* BitTorrent protocol encryption...

  • Phenocopy
    A phenocopy is an individual whose phenotype , under a particular environmental condition, is identical to the one of another individual whose phenotype is determined by the genotype. In other words the phenocopy environmental condition mimics the phenotype produced by a gene.The term was coined by...

  • Phenotype
    A phenotype is an organism's observable characteristics or traits: such as its morphology, development, biochemical or physiological properties, behavior, and products of behavior...

  • Phenotypic variance
  • Phenylketonuria
    Phenylketonuria is an autosomal recessive metabolic genetic disorder characterized by a mutation in the gene for the hepatic enzyme phenylalanine hydroxylase , rendering it nonfunctional. This enzyme is necessary to metabolize the amino acid phenylalanine to the amino acid tyrosine...

  • Pheromone
    A pheromone is a secreted or excreted chemical factor that triggers a social response in members of the same species. Pheromones are chemicals capable of acting outside the body of the secreting individual to impact the behavior of the receiving individual...

  • Phosphodiester bond
    Phosphodiester bond
    A phosphodiester bond is a group of strong covalent bonds between a phosphate group and two 5-carbon ring carbohydrates over two ester bonds. Phosphodiester bonds are central to all known life, as they make up the backbone of each helical strand of DNA...

  • Photoreactivation
  • Phyletic evolution
  • Phyletic gradualism
    Phyletic gradualism
    Phyletic gradualism is a model of evolution which theorizes that most speciation is slow, uniform and gradual. When evolution occurs in this mode, it is usually by the steady transformation of a whole species into a new one...

  • Phylogenetic tree
    Phylogenetic tree
    A phylogenetic tree or evolutionary tree is a branching diagram or "tree" showing the inferred evolutionary relationships among various biological species or other entities based upon similarities and differences in their physical and/or genetic characteristics...

  • Phylogenetics
    In biology, phylogenetics is the study of evolutionary relatedness among groups of organisms , which is discovered through molecular sequencing data and morphological data matrices...

  • Physical map
  • Piebald
    A piebald or pied animal is one that has a spotting pattern of large unpigmented, usually white, areas of hair, feathers, or scales and normally pigmented patches, generally black. The colour of the animal's skin underneath its coat is also pigmented under the dark patches and unpigmented under...

  • Pilus
    right|thumb|350px|Schematic drawing of bacterial conjugation. 1- Donor cell produces pilus. 2- Pilus attaches to recipient cell, brings the two cells together. 3- The mobile plasmid is nicked and a single strand of DNA is then transferred to the recipient cell...

  • PKU
    Phenylketonuria is an autosomal recessive metabolic genetic disorder characterized by a mutation in the gene for the hepatic enzyme phenylalanine hydroxylase , rendering it nonfunctional. This enzyme is necessary to metabolize the amino acid phenylalanine to the amino acid tyrosine...

  • Plant breeding
    Plant breeding
    Plant breeding is the art and science of changing the genetics of plants in order to produce desired characteristics. Plant breeding can be accomplished through many different techniques ranging from simply selecting plants with desirable characteristics for propagation, to more complex molecular...

  • Plasmid
    In microbiology and genetics, a plasmid is a DNA molecule that is separate from, and can replicate independently of, the chromosomal DNA. They are double-stranded and, in many cases, circular...

  • Plastid
    Plastids are major organelles found in the cells of plants and algae. Plastids are the site of manufacture and storage of important chemical compounds used by the cell...

  • Pleiotropic mutation
  • Pleiotropy
    Pleiotropy occurs when one gene influences multiple phenotypic traits. Consequently, a mutation in a pleiotropic gene may have an effect on some or all traits simultaneously...

  • Pluripotency
  • Point mutation
    Point mutation
    A point mutation, or single base substitution, is a type of mutation that causes the replacement of a single base nucleotide with another nucleotide of the genetic material, DNA or RNA. Often the term point mutation also includes insertions or deletions of a single base pair...

  • Poisson distribution
    Poisson distribution
    In probability theory and statistics, the Poisson distribution is a discrete probability distribution that expresses the probability of a given number of events occurring in a fixed interval of time and/or space if these events occur with a known average rate and independently of the time since...

  • Poky mutation
  • Polar body
    Polar body
    A polar body is a cell structure found inside an ovum. Both animal and plant ova possess it. It is also known as a polar cell.Asymmetrical cell division leads to the production of polar bodies during oogenesis. To conserve nutrients, the majority of cytoplasm is segregated into the secondary...

  • Polar granules
  • Polar mutation
    Polar mutation
    A polar mutation affects expression of downstream genes or operons. It can also affect the expression of the gene in which it occurs, if it occurs in a transcribed region. These mutations tend to occur early within the sequence of genes and can be nonsense, frameshift or insertion mutations...

  • Polar overdominance
    Polar overdominance
    Polar overdominance is a unique form of inheritance whereby a mutant Callipyge allele must be inherited from the father to cause muscle hypertrophy .-See also:*Imprinting...

  • Polarity
    Chemical polarity
    In chemistry, polarity refers to a separation of electric charge leading to a molecule or its chemical groups having an electric dipole or multipole moment. Polar molecules interact through dipole–dipole intermolecular forces and hydrogen bonds. Molecular polarity is dependent on the difference in...

  • Polarity gene
  • Pollen grain
  • Poly(A) tail
  • Polyacrylamide
    Polyacrylamide is a polymer formed from acrylamide subunits. It can be synthesized as a simple linear-chain structure or cross-linked, typically using N,N-methylenebisacrylamide. Polyacrylamide is not toxic...

  • Polycistronic
  • Polycistronic mRNA
  • Polydactyly
    Polydactyly or polydactylism , also known as hyperdactyly, is a congenital physical anomaly in humans, dogs, and cats having supernumerary fingers or toes....

  • Polygene
    A polygene, multiple factor, multiple gene inheritance, or quantitative gene is a group of non-allelic genes that together influence a phenotypic trait. The loci or identities of the non-allelic genes are often unknown to biologist...

  • Polygenic disorder
  • Polymerase
    A polymerase is an enzyme whose central function is associated with polymers of nucleic acids such as RNA and DNA.The primary function of a polymerase is the polymerization of new DNA or RNA against an existing DNA or RNA template in the processes of replication and transcription...

  • Polymerize
  • Polymorphism
    Polymorphism (biology)
    Polymorphism in biology occurs when two or more clearly different phenotypes exist in the same population of a species — in other words, the occurrence of more than one form or morph...

  • Polypeptide
  • Polyploid
  • Polyribosome
  • Polysaccharide
    Polysaccharides are long carbohydrate molecules, of repeated monomer units joined together by glycosidic bonds. They range in structure from linear to highly branched. Polysaccharides are often quite heterogeneous, containing slight modifications of the repeating unit. Depending on the structure,...

  • Polysome
    Polyribosomes also known as ergosomes are a cluster of ribosomes, bound to a mRNA molecule, first discovered and characterized by Jonathan Warner, Paul Knopf, and Alex Rich in 1963. Many ribosomes read one mRNA simultaneously, progressing along the mRNA to synthesize the same protein...

  • Polytene chromosome
    Polytene chromosome
    To increase cell volume, some specialized cells undergo repeated rounds of DNA replication without cell division , forming a giant polytene chromosome...

  • Population
    A population is all the organisms that both belong to the same group or species and live in the same geographical area. The area that is used to define a sexual population is such that inter-breeding is possible between any pair within the area and more probable than cross-breeding with individuals...

  • Population genetics
    Population genetics
    Population genetics is the study of allele frequency distribution and change under the influence of the four main evolutionary processes: natural selection, genetic drift, mutation and gene flow. It also takes into account the factors of recombination, population subdivision and population...

  • Position effect
    Position effect
    Position effect is the effect on the expression of a gene when its location in a chromosome is changed, often by translocation. This has been well described in Drosophila with respect to eye color and is known as position effect variegation ....

  • Positional cloning
  • Positive control
    Scientific control
    Scientific control allows for comparisons of concepts. It is a part of the scientific method. Scientific control is often used in discussion of natural experiments. For instance, during drug testing, scientists will try to control two groups to keep them as identical and normal as possible, then...

  • Pre-mRNA
  • Precancerous polyp
  • Predisposition
    Genetic predisposition
    A genetic predisposition is a genetic affectation which influences the phenotype of an individual organism within a species or population but by definition that phenotype can also be modified by the environmental conditions. In the rest of the population, conditions cannot have that effect...

  • Preemptor stem
  • Prenatal diagnosis
    Prenatal diagnosis
    Prenatal diagnosis or prenatal screening is testing for diseases or conditions in a fetus or embryo before it is born. The aim is to detect birth defects such as neural tube defects, Down syndrome, chromosome abnormalities, genetic diseases and other conditions, such as spina bifida, cleft palate,...

  • Pribnow box
    Pribnow box
    The Pribnow box is the sequence TATAAT of six nucleotides that is an essential part of a promoter site on DNA for transcription to occur in bacteria...

  • Primary oocyte
  • Primary spermatocyte
  • Primary structure
    Primary structure
    The primary structure of peptides and proteins refers to the linear sequence of its amino acid structural units. The term "primary structure" was first coined by Linderstrøm-Lang in 1951...

  • Primary transcript
    Primary transcript
    A primary transcript is an RNA molecule that has not yet undergone any modification after its synthesis. For example, a precursor messenger RNA is a primary transcript that becomes a messenger RNA after processing, and a primary microRNA precursor becomes a microRNA after processing....

  • Primase
    DNA primase is an enzyme involved in the replication of DNA.Primase catalyzes the synthesis of a short RNA segment called a primer complementary to a ssDNA template...

  • Primer
    Primer (molecular biology)
    A primer is a strand of nucleic acid that serves as a starting point for DNA synthesis. They are required for DNA replication because the enzymes that catalyze this process, DNA polymerases, can only add new nucleotides to an existing strand of DNA...

  • Primosome
    In molecular biology, a primosome is a protein complex responsible for creating RNA primers on single stranded DNA during DNA replication.The primosome consists of seven proteins: DnaG primase, DnaB helicase, DnaC helicase assistant, DnaT, PriA, Pri B, and PriC...

  • Prion
    A prion is an infectious agent composed of protein in a misfolded form. This is in contrast to all other known infectious agents which must contain nucleic acids . The word prion, coined in 1982 by Stanley B. Prusiner, is a portmanteau derived from the words protein and infection...

  • Privacy
    Privacy is the ability of an individual or group to seclude themselves or information about themselves and thereby reveal themselves selectively...

  • Pro
    Proline is an α-amino acid, one of the twenty DNA-encoded amino acids. Its codons are CCU, CCC, CCA, and CCG. It is not an essential amino acid, which means that the human body can synthesize it. It is unique among the 20 protein-forming amino acids in that the α-amino group is secondary...

  • Probability
    Probability is ordinarily used to describe an attitude of mind towards some proposition of whose truth we arenot certain. The proposition of interest is usually of the form "Will a specific event occur?" The attitude of mind is of the form "How certain are we that the event will occur?" The...

  • Probability theory
    Probability theory
    Probability theory is the branch of mathematics concerned with analysis of random phenomena. The central objects of probability theory are random variables, stochastic processes, and events: mathematical abstractions of non-deterministic events or measured quantities that may either be single...

  • Proband
    Proband, or propositus, is a term used most often in medical genetics and other medical fields to denote a particular subject being studied or reported on. On pedigrees, the proband is noted with an arrow and the box or circle shaded accordingly...

  • Probe
    Hybridization probe
    In molecular biology, a hybridization probe is a fragment of DNA or RNA of variable length , which is used in DNA or RNA samples to detect the presence of nucleotide sequences that are complementary to the sequence in the probe...

  • Processivity
    In molecular biology, processivity is a measure of the average number of nucleotides added by a DNA polymerase enzyme per association/disassociation with the template. DNA polymerases associated with DNA replication tend to be highly processive, while those associated with DNA repair tend to have...

  • Product of meiosis
  • Product rule
    Product rule
    In calculus, the product rule is a formula used to find the derivatives of products of two or more functions. It may be stated thus:'=f'\cdot g+f\cdot g' \,\! or in the Leibniz notation thus:...

  • Proflavin
  • Progeny testing
    Progeny testing
    Progeny Testing is a test of the value for selective breeding of an individual's genotype by looking at the progeny produced by different matings.- Progeny Testing :...

  • Prognosis
    Prognosis is a medical term to describe the likely outcome of an illness.When applied to large statistical populations, prognostic estimates can be very accurate: for example the statement "45% of patients with severe septic shock will die within 28 days" can be made with some confidence, because...

  • Prokaryote
    The prokaryotes are a group of organisms that lack a cell nucleus , or any other membrane-bound organelles. The organisms that have a cell nucleus are called eukaryotes. Most prokaryotes are unicellular, but a few such as myxobacteria have multicellular stages in their life cycles...

  • Prokaryotic cell
  • Promoter
  • Pronucleus
    A pronucleus is the nucleus of a sperm or an egg cell during the process of fertilization, after the sperm enters the ovum, but before they fuse. Sperm and egg cells are haploid, meaning they carry half the number of chromosomes...

  • Proofread
  • Proofreader genes
  • Prophage
    A prophage is a phage genome inserted and integrated into the circular bacterial DNA chromosome. A prophage, also known as a temperate phage, is any virus in the lysogenic cycle; it is integrated into the host chromosome or exists as an extrachromosomal plasmid. Technically, a virus may be called...

  • Prophase
    Prophase, from the ancient Greek πρό and φάσις , is a stage of mitosis in which the chromatin condenses into a highly ordered structure called a chromosome in which the chromatin becomes visible. This process, called chromatin condensation, is mediated by the condensin complex...

  • Prophylactic surgery
  • Proplastid
  • Propositus
  • Prostate cancer
    Prostate cancer
    Prostate cancer is a form of cancer that develops in the prostate, a gland in the male reproductive system. Most prostate cancers are slow growing; however, there are cases of aggressive prostate cancers. The cancer cells may metastasize from the prostate to other parts of the body, particularly...

  • Protease
    A protease is any enzyme that conducts proteolysis, that is, begins protein catabolism by hydrolysis of the peptide bonds that link amino acids together in the polypeptide chain forming the protein....

  • Protein
    Proteins are biochemical compounds consisting of one or more polypeptides typically folded into a globular or fibrous form, facilitating a biological function. A polypeptide is a single linear polymer chain of amino acids bonded together by peptide bonds between the carboxyl and amino groups of...

  • Protein product
  • Proteome
    The proteome is the entire set of proteins expressed by a genome, cell, tissue or organism. More specifically, it is the set of expressed proteins in a given type of cells or an organism at a given time under defined conditions. The term is a portmanteau of proteins and genome.The term has been...

  • Proteomics
    Proteomics is the large-scale study of proteins, particularly their structures and functions. Proteins are vital parts of living organisms, as they are the main components of the physiological metabolic pathways of cells. The term "proteomics" was first coined in 1997 to make an analogy with...

  • Proteus syndrome
    Proteus syndrome
    Proteus syndrome, also known as Wiedemann's syndrome , is a congenital disorder that causes skin overgrowth and atypical bone development, often accompanied by tumors over half the body....

  • Proto-oncogene
  • Protoplast
    Protoplast, from the ancient Greek πρῶτον + verb πλάθω or πλάττω , initially referred to the first organized body of a species.Protoplast has several biological definitions:...

  • Prototroph
  • Provirus
    A provirus is a virus genome that is integrated into the DNA of a host cell.This state can be a stage of virus replication, or a state that persists over longer periods of time as either inactive viral infections or an endogenous retrovirus. In inactive viral infections the virus will not replicate...

  • Pseudoallele
  • Pseudoautosomal region
    Pseudoautosomal region
    The pseudoautosomal regions, PAR1 and PAR2 are homologous sequences of nucleotides on the X and Y chromosomes.The pseudoautosomal regions get their name because any genes located within them are inherited just like any autosomal genes...

  • Pseudodominance
    Pseudodominance is the situation in which the inheritance of an autosomal recessive trait mimics an autosomal dominant pattern.The pattern of inheritance in which the recessive allele could give its expression in absence of its dominant allele is known as pseudodominance...

  • Pseudogene
    Pseudogenes are dysfunctional relatives of known genes that have lost their protein-coding ability or are otherwise no longer expressed in the cell...

  • Public policy
    Public policy
    Public policy as government action is generally the principled guide to action taken by the administrative or executive branches of the state with regard to a class of issues in a manner consistent with law and institutional customs. In general, the foundation is the pertinent national and...

  • Puff
    Puff may refer to:In foods with high air content:*Puffed grain*Puff pastry*Cocoa Puffs*Cream puff, profiteroleIn low-density objects:*Powder puff, face-powder applicator*Puffs, a brand of facial tissueIn animals:...

  • Punnett square
    Punnett square
    The Punnett square is a diagram that is used to predict an outcome of a particular cross or breeding experiment. It is named after Reginald C. Punnett, who devised the approach, and is used by biologists to determine the probability of an offspring's having a particular genotype...

  • Purine
    A purine is a heterocyclic aromatic organic compound, consisting of a pyrimidine ring fused to an imidazole ring. Purines, including substituted purines and their tautomers, are the most widely distributed kind of nitrogen-containing heterocycle in nature....

  • Purines
  • Pyrimidine
    Pyrimidine is a heterocyclic aromatic organic compound similar to benzene and pyridine, containing two nitrogen atoms at positions 1 and 3 of the six-member ring...


  • R factor
  • R plasmid
  • Radiation hybrid
  • RAM mutation
  • Random genetic drift
  • Random mating
  • Rare-cutter enzyme
    Rare-cutter enzyme
    A rare-cutter enzyme is a restriction enzyme with a recognition sequence which occurs only rarely in a genome. An example is NotI, which cuts after the first GC of a 5'-GCGGCCGC-3' sequence; restriction enzymes with seven and eight base pair recognition sequences are often also called rare-cutter...

  • Reading frame
    Reading frame
    In biology, a reading frame is a way of breaking a sequence of nucleotides in DNA or RNA into three letter codons which can be translated in amino acids. There are 3 possible reading frames in an mRNA strand: each reading frame corresponding to starting at a different alignment...

  • Readthrough
  • Reannealing
    Reannealing is the process by which two single strands of DNA combine to form double-stranded DNA. The term is most commonly used in its application in DNA amplification, the process by which DNA is copied in the lab....

  • Rec system
  • Receptor element
  • Recessive allele
  • Recessive gene
  • Recessive phenotype
  • Reciprocal altruism
    Reciprocal altruism
    In evolutionary biology, reciprocal altruism is a behaviour whereby an organism acts in a manner that temporarily reduces its fitness while increasing another organism's fitness, with the expectation that the other organism will act in a similar manner at a later time...

  • Reciprocal cross
    Reciprocal cross
    In genetics, a reciprocal cross is a breeding experiment designed to test the role of parental sex on a given inheritance pattern. All parent organisms must be true breeding to properly carry out such an experiment. In one cross, a male expressing the trait of interest will be crossed with a...

  • Recombinant
  • Recombinant clone
  • Recombinant DNA
    Recombinant DNA
    Recombinant DNA molecules are DNA sequences that result from the use of laboratory methods to bring together genetic material from multiple sources, creating sequences that would not otherwise be found in biological organisms...

  • Recon
    Genetic recombination
    Genetic recombination is a process by which a molecule of nucleic acid is broken and then joined to a different one. Recombination can occur between similar molecules of DNA, as in homologous recombination, or dissimilar molecules, as in non-homologous end joining. Recombination is a common method...

  • Reduction division
  • Redundant DNA
  • Regression
    Regression (medicine)
    Regression in medicine is a characteristic of diseases to show lighter symptoms without completely disappearing. At a later point, symptoms may return. These symptoms are then called recidive....

  • Regulator element
  • Regulator gene
    Regulator gene
    A regulator gene, regulator, or regulatory gene is a gene involved in controlling the expression of one or more other genes. A regulator gene may encode a protein, or it may work at the level of RNA, as in the case of genes encoding microRNAs....

  • Relaxed mutant
  • Renal cell cancer
    Renal cell carcinoma
    Renal cell carcinoma is a kidney cancer that originates in the lining of the proximal convoluted tubule, the very small tubes in the kidney that filter the blood and remove waste products. RCC is the most common type of kidney cancer in adults, responsible for approximately 80% of cases...

  • Renal cell carcinoma
    Renal cell carcinoma
    Renal cell carcinoma is a kidney cancer that originates in the lining of the proximal convoluted tubule, the very small tubes in the kidney that filter the blood and remove waste products. RCC is the most common type of kidney cancer in adults, responsible for approximately 80% of cases...

  • Renner complex
  • Repeat sequences
  • Repetitive DNA
  • Replica plating
    Replica plating
    In molecular biology and microbiology, replica plating is a technique in which one or more secondary Petri plates containing different solid selective growth media are inoculated with the same colonies of microorganisms from a primary plate , reproducing the original spatial...

  • Replication fork
    Replication fork
    The replication fork is a structure that forms within the nucleus during DNA replication. It is created by helicases, which break the hydrogen bonds holding the two DNA strands together. The resulting structure has two branching "prongs", each one made up of a single strand of DNA...

  • Replicon
    Replicon (genetics)
    A replicon is a DNA molecule or RNA molecule, or a region of DNA or RNA, that replicates from a single origin of replication.For most prokaryotic chromosomes, the replicon is the entire chromosome. One notable exception found comes from archaea, where two Sulfolobus species have been shown to...

  • Replisome
    The replisome is a complex molecular machine that carries out replication of DNA. It is made up of a number of subcomponents that each provide a specific function during the process of replication.-Major components:...

  • Reporter gene
    Reporter gene
    In molecular biology, a reporter gene is a gene that researchers attach to a regulatory sequence of another gene of interest in cell culture, animals or plants. Certain genes are chosen as reporters because the characteristics they confer on organisms expressing them are easily identified and...

  • Repressible operon
  • Repression
  • Repressor
    In molecular genetics, a repressor is a DNA-binding protein that regulates the expression of one or more genes by binding to the operator and blocking the attachment of RNA polymerase to the promoter, thus preventing transcription of the genes. This blocking of expression is called...

  • Reproductive cells
  • Reproductive success
    Reproductive success
    Reproductive success is defined as the passing of genes onto the next generation in a way that they too can pass those genes on. In practice, this is often a tally of the number of offspring produced by an individual. A more correct definition, which incorporates inclusive fitness, is the...

  • Repulsion
    Repulsion is a 1965 British psychological thriller film directed by Roman Polanski, based on a scenario by Gérard Brach and Roman Polanski. It was Polanski's first English language film, and was shot in Britain, as such being his second film made outside his native Poland. The cast includes...

  • Resolving power
    Resolving power
    Resolving power may refer to:* Angular resolution* Spectral resolution* Resolution...

  • Restriction digest
    Restriction digest
    A restriction digest is a procedure used in molecular biology to prepare DNA for analysis or other processing. It is sometimes termed DNA fragmentation...

  • Restriction enzyme
    Restriction enzyme
    A Restriction Enzyme is an enzyme that cuts double-stranded DNA at specific recognition nucleotide sequences known as restriction sites. Such enzymes, found in bacteria and archaea, are thought to have evolved to provide a defense mechanism against invading viruses...

  • Restriction enzymes
  • Restriction map
  • Retinitis pigmentosa
    Retinitis pigmentosa
    Retinitis pigmentosa is a group of genetic eye conditions that leads to incurable blindness. In the progression of symptoms for RP, night blindness generally precedes tunnel vision by years or even decades. Many people with RP do not become legally blind until their 40s or 50s and retain some...

  • Retinoblastoma
    Retinoblastoma is a rapidly developing cancer that develops in the cells of retina, the light-detecting tissue of the eye. In the developed world, Rb has one of the best cure rates of all childhood cancers , with more than nine out of every ten sufferers surviving into...

  • Retroviral infection
  • Retrovirus
    A retrovirus is an RNA virus that is duplicated in a host cell using the reverse transcriptase enzyme to produce DNA from its RNA genome. The DNA is then incorporated into the host's genome by an integrase enzyme. The virus thereafter replicates as part of the host cell's DNA...

  • Reverse genetics
    Reverse genetics
    Reverse genetics is an approach to discovering the function of a gene by analyzing the phenotypic effects of specific gene sequences obtained by DNA sequencing. This investigative process proceeds in the opposite direction of so-called forward genetic screens of classical genetics...

  • Reversion
  • RF
    Genetic linkage
    Genetic linkage is the tendency of certain loci or alleles to be inherited together. Genetic loci that are physically close to one another on the same chromosome tend to stay together during meiosis, and are thus genetically linked.-Background:...

  • RFLP
  • RFLP mapping
  • Rho
    Rho factor
    A ρ factor is a prokaryotic protein involved in the termination of transcription.Rho factor is an essential transcription protein in prokaryotes. In Escherichia coli, it is a ~275 kD hexamer of identical subunits. Each subunit has an RNA-binding domain and an ATP-hydrolysis domain...

  • Ribonucleic acid
  • Ribonucleotide
    A ribonucleotide or ribotide is a nucleotide in which a purine or pyrimidine base is linked to a ribose molecule and exactly one phosphate group. In living organisms the most common bases for ribonucleotides are adenine , guanine , cytosine , or uracil ....

  • Ribose
    Ribose is an organic compound with the formula C5H10O5; specifically, a monosaccharide with linear form H––4–H, which has all the hydroxyl groups on the same side in the Fischer projection....

  • Ribosomal protein
    Ribosomal protein
    A ribosomal protein is any of the proteins that, in conjunction with rRNA, make up the ribosomal subunits involved in the cellular process of translation. A large part of the knowledge about these organic molecules has come from the study of E. coli ribosomes. Most ribosomic proteins have been...

  • Ribosomal RNA
    Ribosomal RNA
    Ribosomal ribonucleic acid is the RNA component of the ribosome, the enzyme that is the site of protein synthesis in all living cells. Ribosomal RNA provides a mechanism for decoding mRNA into amino acids and interacts with tRNAs during translation by providing peptidyl transferase activity...

  • Ribosome
    A ribosome is a component of cells that assembles the twenty specific amino acid molecules to form the particular protein molecule determined by the nucleotide sequence of an RNA molecule....

  • Ribosomes
  • Ribozyme
    A ribozyme is an RNA molecule with a well defined tertiary structure that enables it to catalyze a chemical reaction. Ribozyme means ribonucleic acid enzyme. It may also be called an RNA enzyme or catalytic RNA. Many natural ribozymes catalyze either the hydrolysis of one of their own...

  • Risk communication
  • RNA
    Ribonucleic acid , or RNA, is one of the three major macromolecules that are essential for all known forms of life....

  • RNA editing
    RNA editing
    The term RNA editing describes those molecular processes in which the information content in an RNA molecule is altered through a chemical change in the base makeup. To date, such changes have been observed in tRNA, rRNA, mRNA and microRNA molecules of eukaryotes but not prokaryotes...

  • RNA phage
  • RNA polymerase
    RNA polymerase
    RNA polymerase is an enzyme that produces RNA. In cells, RNAP is needed for constructing RNA chains from DNA genes as templates, a process called transcription. RNA polymerase enzymes are essential to life and are found in all organisms and many viruses...

  • RNA replicase
  • Robertsonian fusion
  • rRNA
  • Rule of segregation


  • S (Svedberg unit)
  • S-9 mix
  • Sanger sequence
  • Sanger sequencing
  • Sarcoma
    A sarcoma is a cancer that arises from transformed cells in one of a number of tissues that develop from embryonic mesoderm. Thus, sarcomas include tumors of bone, cartilage, fat, muscle, vascular, and hematopoietic tissues...

  • Satellite
    In the context of spaceflight, a satellite is an object which has been placed into orbit by human endeavour. Such objects are sometimes called artificial satellites to distinguish them from natural satellites such as the Moon....

  • Satellite chromosome
    Satellite chromosome
    The part of chromosome beyond the nuclear organiser is very short and appears like sphere .The Satellite Chromosome is the chromosome which has a bulge on the telomeric end and SAT stands for Sine Acid thymonucleinicosince the chromosome on staining show relative deficiency of DNA in the nuclear...

  • Satellite DNA
    Satellite DNA
    Satellite DNA consists of very large arrays of tandemly repeating, non-coding DNA. Satellite DNA is the main component of functional centromeres, and form the main structural constituent of heterochromatin....

  • Scaffold
  • Scanning hypothesis
  • Scientific method
    Scientific method
    Scientific method refers to a body of techniques for investigating phenomena, acquiring new knowledge, or correcting and integrating previous knowledge. To be termed scientific, a method of inquiry must be based on gathering empirical and measurable evidence subject to specific principles of...

  • Screening
  • Screening technique
  • Second-site mutation
  • Secondary oocyte
  • Secondary structure
    Secondary structure
    In biochemistry and structural biology, secondary structure is the general three-dimensional form of local segments of biopolymers such as proteins and nucleic acids...

  • Sector
    - Places :* Sector, Devon, a location in the county of Devon in south-western England* Sector, West Virginia, an unincorporated community in Hampshire County, West Virginia, United States of America- In computing :...

  • Sedimentation
    Sedimentation is the tendency for particles in suspension to settle out of the fluid in which they are entrained, and come to rest against a barrier. This is due to their motion through the fluid in response to the forces acting on them: these forces can be due to gravity, centrifugal acceleration...

  • Segmentation (biology)
    Segmentation (biology)
    Segmentation in biology refers to either a type of gastrointestinal motility or the division of some animal and plant body plans into a series of repetitive segments. This article will focus on the segmentation of animal body plans, specifically using the examples of the phyla Arthropoda,...

  • Segregation
  • Segregational load
  • Segregational petite
  • Selection
    In the context of evolution, certain traits or alleles of genes segregating within a population may be subject to selection. Under selection, individuals with advantageous or "adaptive" traits tend to be more successful than their peers reproductively—meaning they contribute more offspring to the...

  • Selection progress
  • Selective medium
  • Selective neutrality
  • Selective system
  • Self
    The self is an individual person as the object of his or her own reflective consciousness. The self has been studied extensively by philosophers and psychologists and is central to many world religions.-Philosophy:...

  • Self-assembly
    Self-assembly is a term used to describe processes in which a disordered system of pre-existing components forms an organized structure or pattern as a consequence of specific, local interactions among the components themselves, without external direction...

  • Self-fertilization
  • Selfed
  • Selfish DNA
    Selfish DNA
    Selfish DNA refers to those sequences of DNA which, in their purest form, have two distinct properties: the DNA sequence spreads by forming additional copies of itself within the genome; and it makes no specific contribution to the reproductive success of its host organism.This idea was sketched...

  • Sense strand
    Sense strand
    In genetics, a sense strand or coding strand is the segment of double stranded DNA running from 5' - 3' that is complementary to the antisense strand or template strand...

  • Sequence
    In mathematics, a sequence is an ordered list of objects . Like a set, it contains members , and the number of terms is called the length of the sequence. Unlike a set, order matters, and exactly the same elements can appear multiple times at different positions in the sequence...

  • Sequence assembly
    Sequence assembly
    In bioinformatics, sequence assembly refers to aligning and merging fragments of a much longer DNA sequence in order to reconstruct the original sequence. This is needed as DNA sequencing technology cannot read whole genomes in one go, but rather reads small pieces of between 20 and 1000 bases,...

  • Sequence tagged site
  • Sequencing
    In genetics and biochemistry, sequencing means to determine the primary structure of an unbranched biopolymer...

  • Sex chromosome
  • Sex chromosomes
  • Sex determination
    Sex-determination system
    A sex-determination system is a biological system that determines the development of sexual characteristics in an organism. Most sexual organisms have two sexes. In many cases, sex determination is genetic: males and females have different alleles or even different genes that specify their sexual...

  • Sex linkage
    Sex linkage
    Sex linkage is the phenotypic expression of an allele related to the chromosomal sex of the individual. This mode of inheritance is in contrast to the inheritance of traits on autosomal chromosomes, where both sexes have the same probability of inheritance...

  • Sex linked
  • Sex reversal
  • Sex switch
  • Sex-controlled trait
  • Sex-influenced trait
  • Sex-lethal
  • Sex-limited trait
  • Sex-linked
  • Sex-ratio phenotype
  • Sexduction
  • Sexual selection
    Sexual selection
    Sexual selection, a concept introduced by Charles Darwin in his 1859 book On the Origin of Species, is a significant element of his theory of natural selection...

  • Sexual spore
  • Shotgun method
  • Shotgun sequencing
    Shotgun sequencing
    In genetics, shotgun sequencing, also known as shotgun cloning, is a method used for sequencing long DNA strands. It is named by analogy with the rapidly-expanding, quasi-random firing pattern of a shotgun....

  • Shotgun technique
  • Shuttle vector
    Shuttle vector
    A shuttle vector is a vector constructed so that it can propagate in two different host species . Therefore, DNA inserted into a shuttle vector can be tested or manipulated in two different cell types. The main advantage of these vectors is they can be manipulated in E. coli then used in a...

  • Siblings(sibs)
  • Sickle-cell disease
    Sickle-cell disease
    Sickle-cell disease , or sickle-cell anaemia or drepanocytosis, is an autosomal recessive genetic blood disorder with overdominance, characterized by red blood cells that assume an abnormal, rigid, sickle shape. Sickling decreases the cells' flexibility and results in a risk of various...

     (Sickle cell anemia)
  • Sigma factor
    Sigma factor
    A sigma factor is a bacterial transcription initiation factor that enables specific binding of RNA polymerase to gene promoters. Different sigma factors are activated in response to different environmental conditions...

  • Signal hypothesis
  • Signal peptide
    Signal peptide
    A signal peptide is a short peptide chain that directs the transport of a protein.Signal peptides may also be called targeting signals, signal sequences, transit peptides, or localization signals....

  • Signal sequence
  • Silent gene
  • Silent mutation
    Silent mutation
    Silent mutations are DNA mutations that do not result in a change to the amino acid sequence of a protein. They may occur in a non-coding region , or they may occur within an exon in a manner that does not alter the final amino acid sequence...

  • SINE
    Maurice Sinet , known as Siné, is a French cartoonist.As a young man he studied drawing and graphic arts, while earning a living as a cabaret singer. After his military service he started publishing his drawings and also worked as a photo-retoucher for porn magazines. His first published drawing...

  • Single-gene disorder
  • Sister chromatids
    Sister chromatids
    Sister chromatids are two identical copies of a chromatid connected by a centromere. Compare sister chromatids to homologous chromosomes, which are the two different copies of the same chromosome that diploid organisms inherit, one from each parent...

  • Skew
  • Smooth endoplasmic reticulum
  • SNP
    Single nucleotide polymorphism
    A single-nucleotide polymorphism is a DNA sequence variation occurring when a single nucleotide — A, T, C or G — in the genome differs between members of a biological species or paired chromosomes in an individual...

  • SnRNP
    snRNPs , or small nuclear ribonucleoproteins, are RNA-protein complexes that combine with unmodified pre-mRNA and various other proteins to form a spliceosome, a large RNA-protein molecular complex upon which splicing of pre-mRNA occurs...

  • Sociobiology
    Sociobiology is a field of scientific study which is based on the assumption that social behavior has resulted from evolution and attempts to explain and examine social behavior within that context. Often considered a branch of biology and sociology, it also draws from ethology, anthropology,...

  • Solenoid structure
  • Somatic cell
    Somatic cell
    A somatic cell is any biological cell forming the body of an organism; that is, in a multicellular organism, any cell other than a gamete, germ cell, gametocyte or undifferentiated stem cell...

  • Somatic cell hybrid
  • Somatic cells
  • Somatic doubling
  • Somatic mutation
  • Somatic mutations
  • Somatostatin
    Somatostatin is a peptide hormone that regulates the endocrine system and affects neurotransmission and cell proliferation via interaction with G-protein-coupled somatostatin receptors and inhibition of the release of numerous secondary hormones.Somatostatin...

  • SOS box
    SOS box
    SOS box is the region in the promoter of various genes to which the LexA repressor binds to repress the transcription in the absence of DNA damage.-Examples:See Nucleic acid nomenclature for an explanation of non-GATC nucleotide letters...

  • SOS repair
  • SOS response
    SOS response
    The SOS response is a global response to DNA damage in which the cell cycle is arrested and DNA repair and mutagenesis are induced. The SOS uses the RecA protein . The RecA protein, stimulated by single-stranded DNA, is involved in the inactivation of the LexA repressor thereby inducing the response...

  • Southern blot
    Southern blot
    A Southern blot is a method routinely used in molecular biology for detection of a specific DNA sequence in DNA samples. Southern blotting combines transfer of electrophoresis-separated DNA fragments to a filter membrane and subsequent fragment detection by probe hybridization. The method is named...

  • Southern blotting
  • Spacer DNA
    Spacer DNA
    Spacer DNA are regions of non-transcribed DNA between tandemly repeated genes, such as ribosomal RNA genes in eukaryotes.Its function most likely involves ensuring the high rates of transcription associated with these genes....

  • Speciation
    Speciation is the evolutionary process by which new biological species arise. The biologist Orator F. Cook seems to have been the first to coin the term 'speciation' for the splitting of lineages or 'cladogenesis,' as opposed to 'anagenesis' or 'phyletic evolution' occurring within lineages...

  • Species
    In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...

  • Specific-locus test
  • Spectral karyotype
  • Sperm
    The term sperm is derived from the Greek word sperma and refers to the male reproductive cells. In the types of sexual reproduction known as anisogamy and oogamy, there is a marked difference in the size of the gametes with the smaller one being termed the "male" or sperm cell...

  • Spermatid
    The spermatid is the haploid male gametid that results from division of secondary spermatocytes. As a result of meiosis, each spermatid contains only half of the genetic material present in the original primary spermatocyte....

  • Spermatocyte
    A spermatocyte is a male gametocyte, derived from a spermatogonium, which is in the developmental stage of spermatogenesis during which meiosis occurs. It is located in the seminiferous tubules of the testis.-Spermatogenesis:...

  • Spermatogenesis
    Spermatogenesis is the process by which male primary germ cells undergo division, and produce a number of cells termed spermatogonia, from which the primary spermatocytes are derived. Each primary spermatocyte divides into two secondary spermatocytes, and each secondary spermatocyte into two...

  • Spermatogonium
    A spermatogonium is an intermediary male gametogonium in the production of spermatozoa.There are three subtypes:...

  • Spermatozoon
    A spermatozoon is a motile sperm cell, or moving form of the haploid cell that is the male gamete. A spermatozoon joins an ovum to form a zygote...

  • Spermiogenesis
    Spermiogenesis is the final stage of spermatogenesis, which sees the maturation of spermatids into mature, motile spermatozoa. The spermatid is more or less circular cell containing a nucleus Golgi apparatus, centriole and mitochondria...

  • Spina bifida
    Spina bifida
    Spina bifida is a developmental congenital disorder caused by the incomplete closing of the embryonic neural tube. Some vertebrae overlying the spinal cord are not fully formed and remain unfused and open. If the opening is large enough, this allows a portion of the spinal cord to protrude through...

  • Spindle
  • Spiral cleavage
  • Spirillum
    Spirillum in microbiology refers to a bacterium with a cell body that twists like a spiral. It is the third distinct bacterial cell shape type besides coccus and bacillus cells.-Taxonomic:...

  • Splice site
  • Spliceosome
    A spliceosome is a complex of snRNA and protein subunits that removes introns from a transcribed pre-mRNA segment. This process is generally referred to as splicing.-Composition:...

  • Splicing
  • Spontaneous mutation
  • Sporadic cancer
  • Spore
    In biology, a spore is a reproductive structure that is adapted for dispersal and surviving for extended periods of time in unfavorable conditions. Spores form part of the life cycles of many bacteria, plants, algae, fungi and some protozoa. According to scientist Dr...

  • Sporophyte
    All land plants, and some algae, have life cycles in which a haploid gametophyte generation alternates with a diploid sporophyte, the generation of a plant or algae that has a double set of chromosomes. A multicellular sporophyte generation or phase is present in the life cycle of all land plants...

  • Stacking
    Stacking may refer to:* Stacking * Stacking , a 2011 game from Double Fine involving matryoshka dolls* A gang signal made with the hands* Sport stacking, played using plastic cups* A film directed and produced by Martin Rosen...

  • Staggered cuts
  • Standard deviation
    Standard deviation
    Standard deviation is a widely used measure of variability or diversity used in statistics and probability theory. It shows how much variation or "dispersion" there is from the average...

  • Statistic
    A statistic is a single measure of some attribute of a sample . It is calculated by applying a function to the values of the items comprising the sample which are known together as a set of data.More formally, statistical theory defines a statistic as a function of a sample where the function...

  • Statistics
    Statistics is the study of the collection, organization, analysis, and interpretation of data. It deals with all aspects of this, including the planning of data collection in terms of the design of surveys and experiments....

  • Stem cell
    Stem cell
    This article is about the cell type. For the medical therapy, see Stem Cell TreatmentsStem cells are biological cells found in all multicellular organisms, that can divide and differentiate into diverse specialized cell types and can self-renew to produce more stem cells...

  • Stem-loop structure
  • Steroid receptor
  • Stochastic
    Stochastic refers to systems whose behaviour is intrinsically non-deterministic. A stochastic process is one whose behavior is non-deterministic, in that a system's subsequent state is determined both by the process's predictable actions and by a random element. However, according to M. Kac and E...

  • Strain
    Strain (biology)
    In biology, a strain is a low-level taxonomic rank used in three related ways.-Microbiology and virology:A strain is a genetic variant or subtype of a micro-organism . For example, a "flu strain" is a certain biological form of the influenza or "flu" virus...

  • Stringent factor
  • Stringent response
    Stringent response
    The stringent response is a stress response that occurs in bacteria and plant chloroplasts in reaction to amino-acid starvation , fatty acid limitation , iron limitation , heat shock and other stress conditions. The stringent response is signaled by the alarmone ppGpp, and modulating...

  • Structural gene
    Structural gene
    A structural gene is a gene that codes for any RNA or protein product other than a regulatory factor . It may code for a structural protein, an enzyme, or an RNA molecule not involved in regulation...

  • Structural genomics
    Structural genomics
    Structural genomics seeks to describe the 3-dimensional structure of every protein encoded by a given genome. This genome-based approach allows for a high-throughput method of structure determination by a combination of experimental and modeling approaches...

  • Substantial equivalence
    Substantial equivalence
    Substantial equivalence is a concept, developed by OECD in 1991, that maintains that a novel food should be considered the same as and as safe as a conventional food if it demonstrates the same characteristics and composition as the conventional food. Substantial equivalence is important from a...

  • Substitution
    Point mutation
    A point mutation, or single base substitution, is a type of mutation that causes the replacement of a single base nucleotide with another nucleotide of the genetic material, DNA or RNA. Often the term point mutation also includes insertions or deletions of a single base pair...

  • Subvital gene
  • Suicide gene
    Suicide gene
    A suicide gene, in genetics, will cause a cell to kill itself through apoptosis. Activation of these genes can be due to many processes, but the main cellular "switch" to induce apoptosis is the p53 protein....

  • Sum rule
    Sum rule
    Sum rule may refer to:*Sum rule in differentiation*Sum rule in integration*Rule of sum, a counting principle in combinatorics*Sum rule in quantum mechanics...

  • Supercoil
  • Supercoiling
  • Supergene
    A supergene is a group of neighbouring genes on a chromosome which are inherited together because of close genetic linkage and are functionally related in an evolutionary sense, although they are rarely co-regulated genetically....

  • Superinfection
    In virology, superinfection is the process by which a cell, that has previously been infected by one virus, gets coinfected with a different strain of the virus, or another virus at a later point in time. Viral superinfections of serious conditions can lead to resistant strains of the virus, which...

  • Supersuppressor
  • Suppressive petite
  • Suppressor gene
  • Suppressor mutation
    Suppressor mutation
    A suppressor mutation is a mutation that counteracts the phenotypic effects of another mutation.There are several classes# mutation within the same gene#* e.g...

  • Svedberg unit
  • Swivelase
  • Sympatric speciation
    Sympatric speciation
    Sympatric speciation is the process through which new species evolve from a single ancestral species while inhabiting the same geographic region. In evolutionary biology and biogeography, sympatric and sympatry are terms referring to organisms whose ranges overlap or are even identical, so that...

  • Synapsis
    Synapsis is the pairing of two homologous chromosomes that occurs during meiosis. It allows matching-up of homologous pairs prior to their segregation, and possible chromosomal crossover between them. Synapsis takes place during prophase I. When homologous chromosomes synapse, their ends are...

  • Synaptonemal complex
    Synaptonemal complex
    The synaptonemal complex is a protein structure that forms between homologous chromosomes during meiosis and that is thought to mediate chromosome pairing, synapsis, and recombination . It is now evident that the synaptonemal complex is not required for genetic recombination...

  • Syncytial blastoderm
  • Syncytium
    In biology, a syncytium is a large cell-like structure; filled with cytoplasm and containing many nuclei. Most cells in eukaryotic organisms have a single nucleus; syncytia are specialized forms used by various organisms.The term may also refer to cells that are connected by specialized membrane...

  • Syndrome
    In medicine and psychology, a syndrome is the association of several clinically recognizable features, signs , symptoms , phenomena or characteristics that often occur together, so that the presence of one or more features alerts the physician to the possible presence of the others...

  • Synexpression
    Synexpression is a type of non-random eukaryotic gene organization. Genes in a synexpression group may not be physically linked, but they are involved in the same process and they are coordinately expressed. It is expected that genes that function in the same process be regulated coordinately...

  • Syngeneic
  • Synteny
    In classical genetics, synteny describes the physical co-localization of genetic loci on the same chromosome within an individual or species. The concept is related to genetic linkage: Linkage between two loci is established by the observation of lower-than-expected recombination frequencies...

  • Synteny test
  • Synthetic medium


  • T-cell receptor
  • T-DNA
  • TACTAAC box
  • Tandem duplication
  • Target theory
  • Targeted mutagenesis
  • TATA box
    TATA box
    The TATA box is a DNA sequence found in the promoter region of genes in archaea and eukaryotes; approximately 24% of human genes contain a TATA box within the core promoter....

  • Tautomeric shift
  • Tay-Sachs disease
    Tay-Sachs disease
    Tay–Sachs disease is an autosomal recessive genetic disorder...

  • Technology transfer
    Technology transfer
    Technology Transfer, also called Transfer of Technology and Technology Commercialisation, is the process of skill transferring, knowledge, technologies, methods of manufacturing, samples of manufacturing and facilities among governments or universities and other institutions to ensure that...

  • Telomerase
    Telomerase is an enzyme that adds DNA sequence repeats to the 3' end of DNA strands in the telomere regions, which are found at the ends of eukaryotic chromosomes. This region of repeated nucleotide called telomeres contains non-coding DNA material and prevents constant loss of important DNA from...

  • Telomere
    A telomere is a region of repetitive DNA sequences at the end of a chromosome, which protects the end of the chromosome from deterioration or from fusion with neighboring chromosomes. Its name is derived from the Greek nouns telos "end" and merοs "part"...

  • Telophase
    Telophase from the ancient Greek "τελος" and "φασις" , is a stage in both meiosis and mitosis in a eukaryotic cell. During telophase, the effects of prophase and prometaphase events are reversed. Two daughter nuclei form in the cell. The nuclear envelopes of the daughter cells are formed from the...

  • Temperate phage
  • Template strand
  • Teratogen
  • Teratogenic
  • Teratogens
  • Terminal redundancy
  • Terminator sequence
  • Tertiary structure
    Tertiary structure
    In biochemistry and molecular biology, the tertiary structure of a protein or any other macromolecule is its three-dimensional structure, as defined by the atomic coordinates.-Relationship to primary structure:...

  • Test cross
    Test cross
    In genetics, a test cross, first introduced by Gregor Mendel, is used to determine if an individual exhibiting a dominant trait is homozygous or heterozygous for that trait...

  • Tester
  • Tetrad
  • Tetrad analysis
  • Tetraparental mouse
  • Tetraploid
  • Tetratype (T)
  • Theta structure
    Theta structure
    A Theta structure is an intermediate structure formed during the replication of a circular DNA molecule , two replication forks can proceed independently around the DNA ring and when viewed from above it resembles the Greek letter "theta"...

  • Thr
    Threonine is an α-amino acid with the chemical formula HO2CCHCHCH3. Its codons are ACU, ACA, ACC, and ACG. This essential amino acid is classified as polar...

  • Three-point cross
    Three-point cross
    In genetics, a three-point cross is used to determine the loci of three genes in an organism's genome.An individual heterozygous for three mutations is crossed with a homozygous recessive individual, and the phenotypes of the progeny are scored...

  • Thymidine
    Thymidine is a chemical compound, more precisely a pyrimidine deoxynucleoside. Deoxythymidine is the DNA nucleoside T, which pairs with deoxyadenosine in double-stranded DNA...

  • Thymine
    Thymine is one of the four nucleobases in the nucleic acid of DNA that are represented by the letters G–C–A–T. The others are adenine, guanine, and cytosine. Thymine is also known as 5-methyluracil, a pyrimidine nucleobase. As the name suggests, thymine may be derived by methylation of uracil at...

  • Thymine dimer
  • Ti plasmid
    Ti plasmid
    Ti plasmid is a circular plasmid that often, but not always, is a part of the genetic equipment that Agrobacterium tumefaciens and Agrobacterium rhizogenes use to transduce its genetic material to plants. Ti stands for tumor inducing. The Ti plasmid is lost when Agrobacterium is grown above 28°C....

  • Topoisomer
    Topoisomers or topological isomers are molecules with the same chemical formula and stereochemical bond connectivities but different topologies. Examples of molecules for which there exist topoisomers include DNA, which can form knots, and catenanes...

  • Topoisomerase
    Topoisomerases are enzymes that regulate the overwinding or underwinding of DNA. The winding problem of DNA arises due to the intertwined nature of its double helical structure. For example, during DNA replication, DNA becomes overwound ahead of a replication fork...

  • Totipotency
  • Totipotent
  • Toxicogenomics
    Toxicogenomics is a field of science that deals with the collection, interpretation, and storage of information about gene and protein activity within particular cell or tissue of an organism in response to toxic substances. Toxicogenomics combines toxicology with genomics or other high throughput...

  • Trait (biological)
  • Trans
  • Trans conformation
  • Trans-acting
    In the field of molecular biology, trans-acting , in general, means "acting from a different molecule"...

  • Transcription
    Transcription (genetics)
    Transcription is the process of creating a complementary RNA copy of a sequence of DNA. Both RNA and DNA are nucleic acids, which use base pairs of nucleotides as a complementary language that can be converted back and forth from DNA to RNA by the action of the correct enzymes...

  • Transcription factor
    Transcription factor
    In molecular biology and genetics, a transcription factor is a protein that binds to specific DNA sequences, thereby controlling the flow of genetic information from DNA to mRNA...

  • Transcriptome
    The transcriptome is the set of all RNA molecules, including mRNA, rRNA, tRNA, and other non-coding RNA produced in one or a population of cells.-Scope:...

  • Transducing particle
  • Transduction
    Transduction (genetics)
    Transduction is the process by which DNA is transferred from one bacterium to another by a virus. It also refers to the process whereby foreign DNA is introduced into another cell via a viral vector. Transduction does not require cell-to-cell contact , and it is DNAase resistant...

  • Transfection
    Transfection is the process of deliberately introducing nucleic acids into cells. The term is used notably for non-viral methods in eukaryotic cells...

  • Transfer RNA
    Transfer RNA
    Transfer RNA is an adaptor molecule composed of RNA, typically 73 to 93 nucleotides in length, that is used in biology to bridge the three-letter genetic code in messenger RNA with the twenty-letter code of amino acids in proteins. The role of tRNA as an adaptor is best understood by...

  • Transferase
    In biochemistry, a transferase is an enzyme that catalyzes the transfer of a functional group from one molecule to another . For example, an enzyme that catalyzed this reaction would be a transferase:In this example, A would be the donor, and B would be the acceptor...

  • Transform
    Transformation (genetics)
    In molecular biology transformation is the genetic alteration of a cell resulting from the direct uptake, incorporation and expression of exogenous genetic material from its surroundings and taken up through the cell membrane. Transformation occurs naturally in some species of bacteria, but it can...

  • Transformation
    Transformation (genetics)
    In molecular biology transformation is the genetic alteration of a cell resulting from the direct uptake, incorporation and expression of exogenous genetic material from its surroundings and taken up through the cell membrane. Transformation occurs naturally in some species of bacteria, but it can...

  • Transformer
  • Transgenic
  • Transgenic organism
  • Transgressive phenotype
  • Transient diploid
  • Transition
    Transition (genetics)
    In genetics, a transition is a point mutation that changes a purine nucleotide to another purine or a pyrimidine nucleotide to another pyrimidine . Approximately two out of three single nucleotide polymorphisms are transitions....

  • Transition mutation
  • Translation
    Translation is the communication of the meaning of a source-language text by means of an equivalent target-language text. Whereas interpreting undoubtedly antedates writing, translation began only after the appearance of written literature; there exist partial translations of the Sumerian Epic of...

  • Translocase (EF-G)
  • Translocation
    Chromosomal translocation
    In genetics, a chromosome translocation is a chromosome abnormality caused by rearrangement of parts between nonhomologous chromosomes. A gene fusion may be created when the translocation joins two otherwise separated genes, the occurrence of which is common in cancer. It is detected on...

  • Transposable element
  • Transposition
  • Transposon
    Transposable elements are sequences of DNA that can move or transpose themselves to new positions within the genome of a single cell. The mechanism of transposition can be either "copy and paste" or "cut and paste". Transposition can create phenotypically significant mutations and alter the cell's...

  • Transversion
    In molecular biology, transversion refers to the substitution of a purine for a pyrimidine or vice versa. It can only be reverted by a spontaneous reversion. Because this type of mutation changes the chemical structure dramatically, the consequences of this change tend to be more drastic than those...

  • Trihybrid
  • Triplet
    Multiple birth
    A multiple birth occurs when more than one fetus is carried to term in a single pregnancy. Different names for multiple births are used, depending on the number of offspring. Common multiples are two and three, known as twins and triplets...

  • Triplet code
  • Triploid
  • Trisomic
  • Trisomy
    A trisomy is a type of polysomy in which there are three copies, instead of the normal two, of a particular chromosome. A trisomy is a type of aneuploidy .-Description and causes:...

  • Tritium
    Tritium is a radioactive isotope of hydrogen. The nucleus of tritium contains one proton and two neutrons, whereas the nucleus of protium contains one proton and no neutrons...

  • tRNA
  • Trp
    Tryptophan is one of the 20 standard amino acids, as well as an essential amino acid in the human diet. It is encoded in the standard genetic code as the codon UGG...

  • True heritability
  • True speciation
  • Truncation selection
    Truncation selection
    Truncation selection is a selection method used in genetic algorithms to select potential candidate solutions for recombination.In truncation selection the candidate solutions are ordered by fitness, and some proportion, p, , of the fittest individuals are selected and reproduced 1/p times...

  • Tumour
  • Tumour virus
  • Turner syndrome
    Turner syndrome
    Turner syndrome or Ullrich-Turner syndrome encompasses several conditions in human females, of which monosomy X is most common. It is a chromosomal abnormality in which all or part of one of the sex chromosomes is absent...

  • Twin spot
  • Twin study
    Twin study
    Twin studies help disentangle the relative importance of environmental and genetic influences on individual traits and behaviors. Twin research is considered a key tool in behavioral genetics and related fields...

  • Two-point cross
  • Type I and type II errors
    Type I and type II errors
    In statistical test theory the notion of statistical error is an integral part of hypothesis testing. The test requires an unambiguous statement of a null hypothesis, which usually corresponds to a default "state of nature", for example "this person is healthy", "this accused is not guilty" or...

  • Typological thinking
  • Tyr


  • Underdominance
    In genetics, underdominance is the opposite of overdominance. It is the selection against the mean of a population distribution, causing disruptive selection and divergent genotypes. Underdominance can also be described as homozygote advantage, wherein homozygous individuals have a higher fitness...

  • Unequal crossover
  • Uninemic chromosome
  • Uniparental disomy
    Uniparental disomy
    Uniparental disomy occurs when a person receives two copies of a chromosome, or part of a chromosome, from one parent and no copies from the other parent.. UPD could involve isodisomy or heterodisomy ....

  • Unique DNA
  • Unmixed codon family
  • Unstable mutation
  • Unusual bases
  • Uracil
    Uracil is one of the four nucleobases in the nucleic acid of RNA that are represented by the letters A, G, C and U. The others are adenine, cytosine, and guanine. In RNA, uracil binds to adenine via two hydrogen bonds. In DNA, the uracil nucleobase is replaced by thymine.Uracil is a common and...

  • URF
    Urf العرف is an Arabic Islamic term referring to the custom, or 'knowledge', of a given society. To be recognized in an Islamic society, Urf must be compatible with Sharia law...

  • Uridine
    Uridine is a molecule that is formed when uracil is attached to a ribose ring via a β-N1-glycosidic bond.If uracil is attached to a deoxyribose ring, it is known as a deoxyuridine....


  • V-J joining
  • Val
    Valine is an α-amino acid with the chemical formula HO2CCHCH2. L-Valine is one of 20 proteinogenic amino acids. Its codons are GUU, GUC, GUA, and GUG. This essential amino acid is classified as nonpolar...

  • Variable region
  • Variance
    In probability theory and statistics, the variance is a measure of how far a set of numbers is spread out. It is one of several descriptors of a probability distribution, describing how far the numbers lie from the mean . In particular, the variance is one of the moments of a distribution...

  • Variant
    Variant is a free cultural magazine based in Glasgow, Scotland, and founded in 1984. Available in both print and internet editions, it is distributed mainly though arts and cultural institutions through Britain and Ireland. Although nominally an arts and cultural bulletin, the magazine also deals...

  • Variate
  • Variation
  • Variegation
    Variegation is the appearance of differently coloured zones in the leaves, and sometimes the stems, of plants. This may be due to a number of causes...

  • Vector
    Vector (molecular biology)
    In molecular biology, a vector is a DNA molecule used as a vehicle to transfer foreign genetic material into another cell. The four major types of vectors are plasmids, viruses, cosmids, and artificial chromosomes...

  • Viability
  • Virion
  • Viroid
    Viroids are plant pathogens that consist of a short stretch of highly complementary, circular, single-stranded RNA without the protein coat that is typical for viruses. The smallest discovered is a 220 nucleobase scRNA associated with the rice yellow mottle sobemovirus...

  • Virulent phage
  • Virus
    A virus is a small infectious agent that can replicate only inside the living cells of organisms. Viruses infect all types of organisms, from animals and plants to bacteria and archaea...

  • VNTR


  • Wahlund effect
    Wahlund effect
    In population genetics, the Wahlund effect refers to reduction of heterozygosity in a population caused by subpopulation structure. Namely, if two or more subpopulations have different allele frequencies then the overall heterozygosity is reduced, even if the subpopulations themselves are in a...

  • Weismann barrier
    Weismann barrier
    The Weismann barrier is the principle that hereditary information moves only from genes to body cells, and never in reverse. In more precise terminology hereditary information moves only from germline cells to somatic cells .This does not refer to the central dogma of molecular biology which...

  • Western blot
    Western blot
    The western blot is a widely used analytical technique used to detect specific proteins in the given sample of tissue homogenate or extract. It uses gel electrophoresis to separate native proteins by 3-D structure or denatured proteins by the length of the polypeptide...

  • Wild type
    Wild type
    Wild type refers to the phenotype of the typical form of a species as it occurs in nature. Originally, the wild type was conceptualized as a product of the standard, "normal" allele at a locus, in contrast to that produced by a non-standard, "mutant" allele...

  • Wilms' tumor
    Wilms' tumor
    Wilms' tumor or nephroblastoma is cancer of the kidneys that typically occurs in children, rarely in adults.Its common name is an eponym, referring to Dr. Max Wilms, the German surgeon who first described this kind of tumor....

  • Wobble
    Wobble base pair
    In molecular biology, a wobble base pair is a non-Watson-Crick base pairing between two nucleotides in RNA molecules. The four main wobble base pairs are guanine-uracil, inosine-uracil, inosine-adenine, and inosine-cytosine . The thermodynamic stability of a wobble base pair is comparable to that...

  • Wolfram syndrome
    Wolfram syndrome
    Wolfram syndrome, also called DIDMOAD , is a rare genetic disorder, causing diabetes mellitus, optic atrophy, and deafness as well as various other possible disorders.It was first described in four siblings in 1938 by Dr. Don J...


  • X chromosome
    X chromosome
    The X chromosome is one of the two sex-determining chromosomes in many animal species, including mammals and is common in both males and females. It is a part of the XY sex-determination system and X0 sex-determination system...

  • X hyperactivation
    X hyperactivation
    X hyperactivation refers to the process in Drosophila by which the structural genes of the male X chromosome are transcribed at the same rate as the two X chromosomes of the female combined....

  • X linkage
  • X linked
  • X-and-Y linkage
  • X-inactivation
    X-inactivation is a process by which one of the two copies of the X chromosome present in female mammals is inactivated. The inactive X chromosome is silenced by packaging into transcriptionally inactive heterochromatin...

  • X:A ratio
    X:A ratio
    The X:A ratio is the ratio between the X chromosome and the number of sets of autosomes in an organism.This ratio is used primarily for determining sex of drosophila flies. Generally, a 1:1 ratio results in a female and a 1:2 ratio results in a male. When calculating the ratio, Y chromosomes are...

  • Xenograft
  • XYY
  • XYY syndrome
    XYY syndrome
    XYY syndrome is an aneuploidy of the sex chromosomes in which a human male receives an extra Y-chromosome, giving a total of 47 chromosomes instead of the more usual 46. This produces a 47,XYY karyotype...


  • Y chromosome
    Y chromosome
    The Y chromosome is one of the two sex-determining chromosomes in most mammals, including humans. In mammals, it contains the gene SRY, which triggers testis development if present. The human Y chromosome is composed of about 60 million base pairs...

  • Y linkage
    Y linkage
    In mammals, Y-linkage refers to when a phenotypic trait is determined by an allele on the Y chromosome. It is also known as holandric inheritance....

  • Y linked
  • Y-chromosomal Aaron
    Y-chromosomal Aaron
    Y-chromosomal Aaron is the name given to the hypothesised most recent common ancestor of many of the patrilineal Jewish priestly caste known as Kohanim . In the Torah, this ancestor is identified as Aaron, the brother of Moses...

  • Y-chromosomal Adam
    Y-chromosomal Adam
    In human genetics, Y-chromosomal Adam is the theoretical most recent common ancestor from whom all living people are descended patrilineally . Many studies report that Y-chromosomal Adam lived as early as around 142,000 years ago and possibly as recently as 60,000 years ago...

  • YAC
    Yeast artificial chromosome
    A yeast artificial chromosome is a vector used to clone DNA fragments larger than 100 kb and up to 3000 kb. YACs are useful for the physical mapping of complex genomes and for the cloning of large genes...

  • Y-chromosome haplogroups by populations
    Y-chromosome haplogroups by populations
    The following articles are lists of human Y-chromosome DNA haplogroups found in populations and various ethnic groups by regions or continents around the world based on relevant studies, and the samples have been taken from individuals identified by linguistic designation.General*Y-DNA haplogroups...

See also

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