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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.
The tree of life. Two domains of life are Bacteria (top branches) and Archaea (bottom branches, including eukaryotes). The two-domain system is a biological classification by which all organisms in the tree of life are classified into two domains, Bacteria and Archaea.
A protist (/ ˈ p r oʊ t ɪ s t /) is any eukaryotic organism (one with cells containing a nucleus) that is not an animal, plant, or fungus.The protists do not form a natural group, or clade, since they exclude certain eukaryotes with whom they share a common ancestor; [a] but, like algae or invertebrates, the grouping is used for convenience.
They are mostly free-living microbes characterized by large cells covered in rows of cilia and containing two kinds of nuclei, micronucleus and macronucleus (e.g., Paramecium, a model organism). [61] Free-living ciliates are usually the top heterotrophs and predators in microbial food webs, feeding on bacteria and smaller eukaryotes, present in ...
The origin of the eukaryotic cell, or eukaryogenesis, is a milestone in the evolution of life, since eukaryotes include all complex cells and almost all multicellular organisms. The last eukaryotic common ancestor (LECA) is the hypothetical origin of all living eukaryotes, [ 71 ] and was most likely a biological population , not a single ...
The three-domain system adds a level of classification (the domains) "above" the kingdoms present in the previously used five- or six-kingdom systems.This classification system recognizes the fundamental divide between the two prokaryotic groups, insofar as Archaea appear to be more closely related to eukaryotes than they are to other prokaryotes – bacteria-like organisms with no cell nucleus.
Eukaryotes are the more developed life forms known as plants, animals, fungi and protists. The term protist came into use historically as a term of convenience for eukaryotes that cannot be strictly classified as plants, animals or fungi. They are not a part of modern cladistics, because they are paraphyletic (lacking a common ancestor).
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]