BIOL 336 Lecture 12: February 23rd 2017
23 Feb 2017
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Document Summary
Review of midterm exam: euglenoids and cryptomonads have no presence of nucleomorph. Supergroup stramenopiles: brown seaweeds, golden-brown diatoms, and many other algae from tiny flagellates to giant kelps, defined in terms of flagellar ultrastructure and molecular data, also known as heterokonts. 2 flagella in vegetative or reproductive cells: ~20% of c fixation of earth, ~40% of the ocean"s primary. Dominate plankton of cold, nutrient rich waters (marine production upwelling regions areas) and recently circulated lake waters. Some produce toxins; others are harmful to fish. Massive sedimentary (diatomaceous earth) accumulation (and oil) Date back to ~150 million years, the early cretaceous: 2. Protoplast enclosed in a frustule (or theca) 2 valves of silica (sio2) with organic coating. Centric: discoid or cylindrical cells, radial symmetry, many discoid plastids. Pennate: bilateral symmetric, two large plate like plastids, raphid penates: raphe system for gliding motility, araphid penates: no raphe system. 2 overlapping components: epitheca: epivalve + epicingulum, hypotheca: hypovalve + hypocingulum, cingulum = girdle.
