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Paramecium (/ ˌ p ær ə ˈ m iː s (i) ə m / PARR-ə-MEE-s(ee-)əm, /-s i ə m /-see-əm, plural "paramecia" only when used as a vernacular name) [2] is a genus of eukaryotic, unicellular ciliates, widespread in freshwater, brackish, and marine environments. Paramecia are often abundant in stagnant basins and ponds.
Osmoregulation is the active regulation of the osmotic pressure of an organism's body fluids, detected by osmoreceptors, to maintain the homeostasis of the organism's water content; that is, it maintains the fluid balance and the concentration of electrolytes (salts in solution which in this case is represented by body fluid) to keep the body fluids from becoming too diluted or concentrated.
The contractile vacuole is predominant in species that do not have a cell wall, but there are exceptions (notably Chlamydomonas) which do possess a cell wall. Through evolution , the contractile vacuole has typically been lost in multicellular organisms, but it still exists in the unicellular stage of several multicellular fungi , as well as in ...
Most ciliates also have one or more prominent contractile vacuoles, which collect water and expel it from the cell to maintain osmotic pressure, or in some function to maintain ionic balance. In some genera, such as Paramecium , these have a distinctive star shape, with each point being a collecting tube.
Paramecium aurelia demonstrate a strong "sex reaction" whereby groups of individuals will cluster together, and emerge in conjugant pairs. This pairing can last up to 12 hours, during which the micronucleus of each organism will be exchanged. [3] In Paramecium aurelia, a cryptic species complex was discovered by observation. [4]
In the pump-leak model of cellular ion homeostasis, energy is utilized to actively transport ions against their electrochemical gradient. [9] The maintenance of this steady state gradient, in turn, is used to do electrical and chemical work, when it is dissipated though the passive movement of ions across the membrane. [9]
Metabolism: transformation of energy by converting chemicals and energy into cellular components and decomposing organic matter . Living things require energy to maintain internal organization (homeostasis) and to produce the other phenomena associated with life.
Paramecium caudatum [1] is a species of unicellular protist in the phylum Ciliophora. [2] They can reach 0.33 mm in length and are covered with minute hair-like organelles called cilia. [3] The cilia are used in locomotion and feeding. [2] The species is very common, and widespread in marine, brackish and freshwater environments. [4] [5]