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Lecture 2 Review

1.Virus particles are non-living outside of other cells. Contain RNA or DNA and a protein coat. They hijack the host cells cell machinery to make more of themselves. The new virus particles leave the host cell and infect other cells.

2.Archaebacteria inhabit extreme environments and may not need oxygen in order to live. Examples are halophiles, thermophiles, and methanogens.

3.Members of Eubacteria are more familiar to us -- they're the ones that generally make us sick.

4.Archaebacteria and Eubacteria are prokaryotes: no membrane-bound organelles; major differences in cell structure compared to eukaryotes; some are photosynthetic or chemosynthetic; are important in the environment and in industry; are the dominant form of life on earth and have been around for at least 3.5 billion years.

5.Kingdom Protista is a miscellaneous assemblage of organisms -- definitely not a natural group.

6.Protista includes the unicellular and multicellular algae, protozoa, water molds, and slime molds.

7.Unicellular algae discussed in this lecture include Euglenophytes, Diatoms, and Dinoflagellates. Euglenophytes and Dinoflagellates can be photosynthetic or heterotrophic; most diatoms are photosynthetic; diatoms have silica skeletons.

8.Diatoms and dinoflagellates have economic importance (diatomaceous earth for filtering and abrasive agents for the former, red tides for the latter).

9.Slime molds (Myxomycophyta) include two basic types -- ones with multinucleate masses and ones that have individual cells that function as a unit during reproduction. Feed on decaying organic matter, fungi, bacteria and other microorganisms. Bright colors and interesting mode of reproduction.

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Last updated April 4, 1997.