Multicellular Algae Multicellular mostly Algae Classified according to

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 O 2 �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…….