Figure 1: A paramecium. The contractile vacuole can be seen as the multiple 'armed' structure on the right-hand side of the ciliate.

A contractile vacuole is a type of vacuole involved in osmoregulation. It pumps excess water out of a cell and is found prominently in freshwater protists. Image File history File links Download high-resolution version (1024x684, 643 KB) A freshwater paramecium under phase contrast illumination. ... Image File history File links Download high-resolution version (1024x684, 643 KB) A freshwater paramecium under phase contrast illumination. ... Schematic of typical animal cell, showing subcellular components. ... Osmoregulation is the active regulation of the osmotic pressure of bodily fluids to maintain the homeostasis of the bodys water content; that is it keeps the bodys fluids from becoming too dilute or too concentrated. ... Drawing of the structure of cork as it appeared under the microscope to Robert Hooke from Micrographia which is the origin of the word cell. Cells in culture, stained for keratin (red) and DNA (green). ... Typical phyla Rhodophyta (red algae) Chromista Heterokontophyta (heterokonts) Haptophyta Cryptophyta (cryptomonads) Alveolates Pyrrhophyta (dinoflagellates) Apicomplexa Ciliophora (ciliates) Excavates Euglenozoa Percolozoa Metamonada Rhizaria Radiolaria Foraminifera Cercozoa Amoebozoa Choanozoa Many others; classification varies The Kingdom Protista or Protoctista is one of the commonly recognized biological kingdoms, including all the eukaryotes except for...

In a Paramecium, a common freshwater protist, the vacuole is surrounded by several canals, which absorb water by osmosis from the cytoplasm. After the canals fill with water, the water is pumped into the vacuole. When the vacuole is full, it expels the water through a pore in the cytoplasm which can be opened and closed. This pore has, in some forms of paramecium, disappeared entirely when not in use, leading to the idea of a "second cell" or an anti semi formal cell in certain types of tuxedo wearing it a very large breed of paramecium even though they are the dumbest of all them. Species Paramecium tetraurelia Paramecium is a genus of unicellular ciliate protozoa, formerly known as slipper animalcules from their slipper shape. ... Impact of a drop of water. ... Osmosis is the net movement of water molecules across a semipermeable membrane from a region of low solute potential to an area of high solute potential (or equivalently, from a region of high solvent potential to a region of low solvent potential). ... Organelles. ... A pore, in general, is some form of opening, usually very small. ...

Other protists, such as Amoeba, have contractile vacuoles that move to the surface of the cell when full and undergo exocytosis. Amoeba, amœba, or ameba is a genus of protozoa that moves by means of temporary projections called pseudopods, and is well-known as a representative unicellular organism. ... This page is currently under construction. ...