Bead theory
Encyclopedia
The bead theory is a disproved hypothesis
that gene
s are arranged on the chromosome
like bead
s 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.
Hypothesis
A hypothesis is a proposed explanation for a phenomenon. The term derives from the Greek, ὑποτιθέναι – hypotithenai meaning "to put under" or "to suppose". For a hypothesis to be put forward as a scientific hypothesis, the scientific method requires that one can test it...
that gene
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...
s are arranged on the chromosome
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...
like bead
Bead
A bead is a small, decorative object that is usually pierced for threading or stringing. Beads range in size from under to over in diameter. A pair of beads made from Nassarius sea snail shells, approximately 100,000 years old, are thought to be the earliest known examples of jewellery. Beadwork...
s on a necklace
Necklace
A necklace is an article of jewellery which is worn around the neck. Necklaces are frequently formed from a metal jewellery chain. Others are woven or manufactured from cloth using string or twine....
. According to this theory, the existence of a gene as a unit of inheritance is recognized through its mutant alleles. Seymour Benzer
Seymour Benzer
Seymour Benzer was an American physicist, molecular biologist and behavioral geneticist. His career began during the molecular biology revolution of the 1950s, and he eventually rose to prominence in the fields of molecular and behavioral genetics. He led a productive genetics research lab both at...
showed in the 1950s that the bead theory was not correct.