Gen Bio2: Archaeplastidal Algae

Glaucophytes

microscopic freshwater algae; double membrane; pigments chlorophyll a and phycobilins; thin peptidoglycan layer

Red Algae (Rhodophyta)

marine, some unicellular but most filamentous to complex, ancient group, non-motile, cellulose microfibrils cell wall

Bangiomorpha pubescens

an extinct red alga from 1.1 bya; oldest known multicellular eukaryote; evidence of sexual reproduction

Unicellular red algae

Cyanidium, Porphyridium

Uniseriate filaments

each branch a single file of cells; Batrachospermum turfosum

Ceramium filaments

central filament buds off short branches that cover it with coricating cells

Multiseriate (pluriseriate) filaments

arising from a single filament, divided up by longitudinal divisions; Polysiphonia

Coralline red algae

secrete CaCO3 skeleton (CO2 sink); important reef builders; creates crustose that stabilizes reef material

Agar

extract of gelatinous red algal cell wall polysaccharides; used as a culture medium in microbiology

Carrageenan

sulfonated polysaccharide in red algal cell walls; thickener and texturizer in ice cream, whipped cream, toothpaste, and cosmetics

Green Algae

Chlorophytes and Charophytes (includes land plants); marine, freshwater, terrestrial/subaerial; unicellular, filamentous, colonial, multicellular, diverse body forms; chl a, chl b, carotenoids

Starch

green algae glucose storage product

Pyrenoid

CO2 concentration center for rubisco within chloroplast stroma

Trentepohlia

Chlorophyta green algae; subaerial/terrestrial; filamentous; on bark and rock in humid places; protective carotenoid pigments mask chlorophylls; symbiont in many lichen associations

Chlorophyta

motile stages (vegetative, zoospores, gametes) with two anterior smooth flagella, single cup shape plasitid fills most of the cell, pyrenoids

Chlamydomonas nivalis

Chlorophyta green algae that colonizes snow, have red carotenoid pigment (astaxanthin)

Volvox

Chlorophyta green algae that is a hollow sphere of flagellate cells, some specialized for sexual and asexual production, differences in flagellar length, detached cells cannot survive independently, true multicellular

Caulerpa

medium-large seaweeds, invasive, three distinct vegetative organs yet is a single cell; assimilator, stolon, and rhizoid

Coenocytes

mitosis occurs without cytokinesis; many nuclei in common cytoplasm; siphonaceous algae (bodies are multinucleate tubes)

Pediastrum and Scenedesmis and Hydrodictyon

Colonial forms with specific shape and cell number, new colonies form inside individual cells by fusion of zoospores

Chara

Charophytes green algae "stonewort" filamentous axes with whorls of lateral branches at nodes; coleochaete (flat disc of radiating cells)

Desmids

Charophyte green algae; 2 mirror-image semi-cells; nucleus in the isthmus between

Zygnematales

closest living relatives of land plants