 7 major phyla of algae  4 are unicellular  3 are multicellular  Many have accessory pigments that allow harvesting of sunlight that chlorphyll a and b do not harvest  Make up most phytoplankton  4 unicellular algae: › Euglenophytes › Chrysophytes › Diatoms › dinoflagellates

 Phylum Euglenophyta  Have two flagella but no cell wall  Separated from zooflagellates due to the presence of a cell wall  Most prevalent of these is euglena › Eyespot – highly specialized structure that allows organism to sense sunlight and move towards it › Also contain “pellicle” that allow them to move through mud when no water is present

 Phylum Chrysophyta (means golden plants)  Yellow-green and golden-brown algae  Chloroplasts contain bright yellow pigments  Contain pectin in their cell walls instead of cellulose (like plants)  Store food in the form of oil instead of starch  Reproduce asexually and sexually

 Phylum Bacillariophyta  Among most abundant and beautiful organisms on earth!  Produce thin cells walls rich in silicon

 Phylum Pyrrophyta  Half are photosynthetic and other half are heterotrophs  Most have two flagella  Reproduce asexually by binary fission  Most are luminescent  Also called “fire plants”