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Colponemid
Colponemids are free-living alveolates, unicellular flagellates related to dinoflagellates, apicomplexans and ciliates. They are predators of other small eukaryotes, found in freshwater, marine and soil environments. They do not form a solid clade, but a sparse group of deep-branching alveolate lineages. Biology Colponemids are flagellated unicellular protists, 8 to 30 μm long, with rounded cell bodies that bear two heterodynamic flagella for rapid swimming. They are only present as swimming cells during their biological life cycle, life cycle. sexual reproduction, Reproduction or resting microbial cyst, cysts are unknown. Cell structure As other alveolates, all colponemids exhibit cortical alveoli and tubular crista, mitochondrial cristae. They present a three-membrane alveolar pellicle without fibrils, theca or micropores. Within the cell is a vesicular cell nucleus, nucleus with a central nucleolus, as well as a very large digestive vacuole (or food vacuole) located at ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alveolate
The alveolates (meaning "pitted like a honeycomb") are a group of protists, considered a major unranked clade or superphylum within Eukaryota. They are currently grouped with the Stramenopiles and Rhizaria among the protists with tubulocristate mitochondria into the SAR supergroup. Characteristics The most notable shared characteristic is the presence of cortical (near the surface) alveoli (sacs). These are flattened vesicles (sacs) arranged as a layer just under the membrane and supporting it, typically contributing to a flexible pellicle (thin skin). In armored dinoflagellates they may contain stiff plates. Alveolates have mitochondria with tubular cristae ( invaginations), and cells often have pore-like intrusions through the cell surface. The group contains free-living and parasitic organisms, predatory flagellates, and photosynthetic organisms. Almost all sequenced mitochondrial genomes of ciliates and apicomplexa are linear. The mitochondria almost all carry mtDN ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
