Multicellular Algae

Multicellular (mostly) Algae Classified according to their photosynthetic pigments 3 Groups: 1)red algae 2)brown algae 3)green algae

Red Algae Belong to phylum Rhodophyta Contain chlorophyll a and phycobilins Can live in deep water Efficient at absorbing light

Brown Algae Belong to phylum phaeophyta Contain chlorophyll a & c as well as fucoxanthin Example: kelp, Sargassum, Macrocystis

Green Algae Belong to phylum Chlorophyta contain chlorophyll a and b, cellulose cell walls, store food as starch. Very similar to land plants Unicellular, colonial, and multicellular

Unicellular green algae Chlamydomonas

Colonial green algae Spirogyra grows in filaments Volvox grows in hollow spheres

Multicellular Green algae Ulva “sea lettuce”

Reproduction in Algae Life cycles of many algae include both a diploid and a haploid generation. They also include a sexual and an asexual generation. This life cycle is known as alternation of generations. Plants follow this type of life cycle.

Ecology of Algae Major food source for life in the oceans Produce much of Earth’s O2 Some is eaten by humans (nori in sushi) or used to make food products like ICE CREAM!!! Used to make many products such as plastics, paints, deodorants, etc…….