Search results
Results from the WOW.Com Content Network
Protists are distributed across all major groups of eukaryotes, including those that contain multicellular algae, green plants, animals, and fungi. If photosynthetic and fungal protists are distinguished from protozoa, they appear as shown in the phylogenetic tree of eukaryotic groups.
[1] [b] In the 21st century, the classification shifted toward a two-kingdom system of protists: Chromista (containing the chromalveolate, rhizarian and hacrobian groups) and Protozoa (containing excavates and all protists more closely related to animals and fungi). [2] The following groups contain protists.
Some protozoa are unikonts while others are bikonts. The Bacteria (= prokaryotes) are subdivided into Eubacteria and Archaebacteria. According to Cavalier-Smith, Eubacteria is the oldest group of terrestrial organisms still living. He classifies the groups which he believes are younger (archaebacteria and eukaryotes) as Neomura.
A few groups of amoebae have retained their flagella, making them amoeboflagellates. [26] Algae. They are the photosynthetic protists, and can be found in most of the main clades, completely intermingled with heterotrophic protists which are traditionally called protozoa. [27]
The hierarchy of biological classification's eight major taxonomic ranks. A domain contains one or more kingdoms. Intermediate minor rankings are not shown. In biology, a kingdom is the second highest taxonomic rank, just below domain. Kingdoms are divided into smaller groups called phyla (singular phylum).
"Marine protists are a polyphyletic group of organisms playing major roles in the ecology and biogeochemistry of the oceans, including performing much of Earth's photosynthesis and driving the carbon, nitrogen, and silicon cycles. In addition, marine protists occupy key positions in the tree of life, including as the closest relatives of ...
Alveolata include around nine major and minor groups. They are diverse in form, and are known to be related by various ultrastructural and genetic similarities: [13] Ciliates – very common protozoa with many short cilia arranged in rows, and two nuclei; Acavomonidia [13] Colponemidia [13]
It gets its name from the combination of "Sarcodina" (which is an older term used for amoeboids) [4] and "Mastigophora" (which is an older term for flagellates). The characteristics of phylum sarcomastigophora are : (1) Nucleus is of one type except in the stages of certain foraminifera. (2) Locomotory organ either pseudopodia or flagella or both.