Chlorophyta--Volvox.ppt

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Chlorophyta--Volvox

Transcript of Chlorophyta--Volvox.ppt

  • Chlorophyta--Volvox

  • VolvoxVolvox is a spherical, freshwater colony of Chlorophyta that is composed of flagellate cells.

    The colonies are very large andcan be seen with the naked eyein most circumstances.

  • Volvox-- overviewEach mature Volvox colony is composed of numerous flagellate cells similar to Chlamydomonas, on the order of 10003000 in total, and embedded in the surface of a hollow sphere or coenobium made of a gelatinous glycoprotein.

  • More VolvoxThe colony is enabled to swim towards light as a result of the eyespots on the cells. Generally located at the anterior of the cell, these eyespots allow for coordinated movement of the colony (connected together by thin strands of cytoplasm).

  • Reproduction The colony can be either asexual or sexual with the asexual colonies having both somatic cells and reproducing cells called gonidia. Gonidia cells are located near the posterior and produce new colonies through rapid reproduction. If sexual reproduction takes place, two types of gametes are produced. Male colonies will release sperm while female colonies will grow into oogametes.

  • Biotic Community MemberVolvox is a freshwater algae and is found in ponds and ditches, even in shallow puddles. It is a vital food source for small animals and serves as a good indicator of the health of a pond or lake, as algae can only exist in oxygen-rich environments.