WebIn microbiology planktology terms the difference between epitheca and hypotheca is that epitheca is the upper half of the theca of a thecate protist such as a diatom or … WebThe outer larger valve is called epitheca. The smaller inner valve is called hypotheca. The cell is covered by mucilaginous layer. The surface of valve has minute pores or pits. It …

Epitheca Glossary - Diatoms of North America

Webhypotheca inner part of frustule epitheca outer part of frustule How do diatoms reproduce? Asexually Division of two cells Separation of frustule Pushes Epitheca and hypotheca away from each other One part becomes bigger than the other Must go through sexual reproduction when diatom becomes too small Marine diatoms WebThe epitheca is composed of a relatively flat upper part (valve face) with downturned edges (valve mantle), called the epivalve, and one or more hooplike girdle bands called the epicingulum. Similarly, the hypotheca is composed of a hypovalve and a hypocingulum. The epicingulum and hypocingulum are collectively known as the girdle. crp maple county ems roblox

Epitheca - definition of epitheca by The Free Dictionary

The larger theca is usually thought of as "upper," and is thus termed the epitheca. The smaller theca is usually thought of as "lower," and is thus called the hypotheca. [1] As the diatom divides, each daughter retains one theca of the original frustule and produces one new theca. See more A frustule is the hard and porous cell wall or external layer of diatoms. The frustule is composed almost purely of silica, made from silicic acid, and is coated with a layer of organic substance, which was referred to in the early … See more A frustule is usually composed of two identically shaped but slightly differently sized thecae. The theca which is a bit smaller has an edge which fits slightly inside the … See more Diatoms have varied life strategies including floating in the water column (phytoplankton), colonising submerged surfaces and living within the surface of deposited sediments. Some cells are essentially cylindrical (centric) while others have an elongated … See more • Frustule on Britannica • diatom frustule on astrographics.com • Geometry and Pattern in Nature 1: Exploring the shapes of diatom frustules with Johan Gielis' Superformula, by Christina Brodie, UK See more Some genera of diatoms develop ridges on the internal surface of the frustules which extend into the inner cavity. The ridges are … See more When diatoms die and their organic material decomposes, the frustules sink to the bottom of the aquatic environment. This remnant … See more As the diatom prepares to separate it undergoes several processes in order to start the production of either a new hypotheca or new epitheca. Once each cell is completely … See more WebA hypotheca is the smaller half of a frustule. The hypotheca is overlapped by the epitheca. In Greek hypotheca means inner sheath. See also frustule, epitheca, valve, and cingulum. Citations Round, F.E., Crawford, R.M. and Mann, D.G. (1990) The Diatoms. Biology and Morphology of the Genera. Cambridge University Press, Cambridge, 747 pp. A B C D E F build it warehouse cape town