Paramecium caudatum
Encyclopedia
Paramecium caudatum are unicellular organisms belonging to the genus
of Paramecium
of the phylum
Ciliophora. They they can reach 0.25mm in length and are covered with minute hair-like projections called cilia. The cilia are used in locomotion and feeding. They are often called slipper animalcules because of their slipper-like shape.
P. caudatum feed on bacteria
by driving them into the biosphereic presser valve with cilia. Their natural habitat is fresh water. They take in water from the hypotonic environment via osmosis
and use bladder-like contractile vacuoles to accumulate excess water from radial canals and periodically expel it through the plasma membrane by contractions of the surrounding cytoplasm
. The contractile vacuoles also serve to maintain osmotic pressure. When moving through the water, they follow a spiral path while rotating on the long axis.
Paramecium have two nuclei
(a large macronucleus and a single compact micronucleus). They cannot survive without the macronucleus and cannot reproduce without the micro-nucleus. Reproduction is either accomplished by binary fission (asexual), conjugation (sexual
), or (rarely) by endomixis, a process involving total nuclear reorganization of individual organisms. During binary fission a fully grown organism divides into two daughter cells. Conjugation consists of the temporary union of 2 organisms and the exchange of micro-nuclear elements. Without the rejuvenating effects of conjugation a paramecium ages and dies. Only opposite mating types, or genetically compatible organisms, can unite in conjugation.
Paramecium caudatum can communicate with neighbors using a non-molecular method, probably photons. The cell populations were separated either with glass allowing photon transmission from 340 nm to longer waves, or quartz being transmittable from 150 nm, i.e. from UVlight to longer waves. Energy uptake, cell division rate and growth correlation were influenced. Like paramecium bursaria, when caudatum is added to synthetic fertilizer, they die.
Genus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...
of Paramecium
Paramecium
Paramecium is a group of unicellular ciliate protozoa, which are commonly studied as a representative of the ciliate group, and range from about 0.05 to 0.35 mm in length. Simple cilia cover the body, which allow the cell to move with a synchronous motion at speeds of approximately 12 body...
of the phylum
Phylum
In biology, a phylum The term was coined by Georges Cuvier from Greek φῦλον phylon, "race, stock," related to φυλή phyle, "tribe, clan." is a taxonomic rank below kingdom and above class. "Phylum" is equivalent to the botanical term division....
Ciliophora. They they can reach 0.25mm in length and are covered with minute hair-like projections called cilia. The cilia are used in locomotion and feeding. They are often called slipper animalcules because of their slipper-like shape.
P. caudatum feed on bacteria
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...
by driving them into the biosphereic presser valve with cilia. Their natural habitat is fresh water. They take in water from the hypotonic environment via osmosis
Osmosis
Osmosis is the movement of solvent molecules through a selectively permeable membrane into a region of higher solute concentration, aiming to equalize the solute concentrations on the two sides...
and use bladder-like contractile vacuoles to accumulate excess water from radial canals and periodically expel it through the plasma membrane by contractions of the surrounding cytoplasm
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...
. The contractile vacuoles also serve to maintain osmotic pressure. When moving through the water, they follow a spiral path while rotating on the long axis.
Paramecium have two nuclei
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...
(a large macronucleus and a single compact micronucleus). They cannot survive without the macronucleus and cannot reproduce without the micro-nucleus. Reproduction is either accomplished by binary fission (asexual), conjugation (sexual
Sexual reproduction
Sexual reproduction is the creation of a new organism by combining the genetic material of two organisms. There are two main processes during sexual reproduction; they are: meiosis, involving the halving of the number of chromosomes; and fertilization, involving the fusion of two gametes and the...
), or (rarely) by endomixis, a process involving total nuclear reorganization of individual organisms. During binary fission a fully grown organism divides into two daughter cells. Conjugation consists of the temporary union of 2 organisms and the exchange of micro-nuclear elements. Without the rejuvenating effects of conjugation a paramecium ages and dies. Only opposite mating types, or genetically compatible organisms, can unite in conjugation.
Paramecium caudatum can communicate with neighbors using a non-molecular method, probably photons. The cell populations were separated either with glass allowing photon transmission from 340 nm to longer waves, or quartz being transmittable from 150 nm, i.e. from UVlight to longer waves. Energy uptake, cell division rate and growth correlation were influenced. Like paramecium bursaria, when caudatum is added to synthetic fertilizer, they die.