WebThe diatoms are a phylum of unicellular photosynthetic algae and are a group significant for their unique structure and ecology. Taxonomy and phylogeny. The diatoms represent a distinct group but the placement of the diatom group is problematic both in terms of level (phylum or class) and in terms of phylogeny (i.e. who are they grouped with). Diatoms belong to a large group of protists, many of which contain plastids rich in chlorophylls a and c. The group has been variously referred to as heterokonts, chrysophytes, chromists or stramenopiles. Many are autotrophs such as golden algae and kelp; and heterotrophs such as water moulds, opalinids, and … See more A diatom (Neo-Latin diatoma) is any member of a large group comprising several genera of algae, specifically microalgae, found in the oceans, waterways and soils of the world. Living diatoms make up a … See more Diatoms are generally 2 to 200 micrometers in size, with a few larger species. Their yellowish-brown chloroplasts, the site of photosynthesis, are typical of heterokonts, having four cell membranes and containing pigments such as the carotenoid See more Most centric and araphid pennate diatoms are nonmotile, and their relatively dense cell walls cause them to readily sink. Planktonic forms in open water usually rely on See more Distribution Diatoms are a widespread group and can be found in the oceans, in fresh water, in soils, and on damp surfaces. They are one of the dominant … See more Diatoms are protists that form massive annual spring and fall blooms in aquatic environments and are estimated to be responsible for … See more Diatom cells are contained within a unique silica cell wall known as a frustule made up of two valves called thecae, that typically overlap one … See more Reproduction and cell size Reproduction among these organisms is asexual by binary fission, during which the diatom divides into … See more
Radiolaria - University College London
WebRadiolaria. Radiolaria are holoplanktonic protozoa and form part of the zooplankton, they are non-motile (except when flagella-bearing reproductive swarmers are produced) but … WebSolution: Diatoms belong to class bacillariophyceae of algae. These are called diatoms due to presence of an accessory brown pigment called diatomin. These are unicellular and non-motile and the motile stage is found in sperms. Their cell walls are silicifred (called frustule), so after the death of the diatom cells the frustules accumulate at ... green valley international school
Biological Classification class 11 MCQ - YB Study
WebA 0.1 − m 3 0.1-\mathrm{m}^{3} 0.1 − m 3 rigid tank initially contains refrigerant-134a at 1.2 MPa and 100 percent quality. The tank is connected by a valve to a supply line that … WebClass: Bacillariophyceae. 1. This class is represented by approximately 200 genera and 600 species. 2. Members are commonly known as diatoms and are commonly found in fresh water, water, in air or on soil. 3. Thallus is unicellular, uninucleate diploid and show radial or bilateral symmetry. 4. WebApr 24, 2015 · Apr 25, 2015. Diatomites belong to the class of plant kingdom algae , diatoms are white, soft and porous in nature, when a diatom dies it leaves behind shells … greenvalley international inc