Plant-Like Protists (Algae) Autotrophs – photosynthetic, have chloroplasts, all have chlorophyll a Classified by pigment types / color group, food storage, cell wall composition (7 phyla) Produce most O 2 on earth No roots, stems, leaves – make gametes in single- celled gametangia Most aquatic, have flagella at some stage of life cycle Store starch in pyrenoids Unicellular (eg. Phytoplankton), multicellular (eg. seaweeds) or colonial

Plant-Like Protists Phylum Chlorophyta – Green Algae Like plants, have chlorophyll a and b, carotenoids, food stored as starch, cellulose in cell walls  common ancestor or plants evolved from green algae Most aquatic, some terrestrial (moist soil, tree trunks – Protococcus) some symbiotic with invertebrates (corals) or fungi (lichens) Some motile, some sessile

Symbiosis w/ Fungi: Lichens Crustose & Foliose

Symbiosis with Cnidarians Some anemones, corals, and jellyfish have symbiotic algae (zooxanthelae)

Unicellular

Colonial

Multicellular / Filamentous

What type of life cycle is this? What is the only step that uses meiosis?

Plant-Like Protists Phylum Phaeophyta – Brown Algae Multicellular Chlorophyll a and b, plus fucoxanthin brown accessory pigment Most marine, include seaweeds and kelp Sargassum – floating seaweed Mycrocystis pyrifera – giant kelp sessile Giant kelp Kelp

Plant-Like Protists Phylum Rhodophyta – Red Algae Chlorophyll a and phycobilins – red accessory pigments that absorb light deep in water  can live in deeper water than other algae Most are marine seaweeds, sessile

Plant-Like Protists Phylum Bacillariophyta - Diatoms Unicellular Cell walls = shells of silicon dioxide  two halves that fit like a pill box  found in beach sand, used in toothpaste, etc. Centric – round or triangular, mostly marine Pennate – rectangular, mostly freshwater Abundant in phytoplankton

Plant-Like Protists Phylum Dinoflagellata - Dinoflagellates Usually unicellular, have two flagella perpendicular to each other Cell walls made of cellulose plates that resemble armour – ex.: Cerratium Most yellow to brown – carotenoids plus chlorophyll a and c A few colorless heterotrophs Some bioluminesce – genus Noctiluca Some produce toxins & red pigment  “red tides”

Ceratium Dinoflagellate “armour” Red tide

Bioluminescence

Plant-Like Protists Phylum Chrysophyta – Golden Algae Unicellular, chlorophyll a and b, yellow due to carotenoids Two flagella on opposite ends of cell Most live in freshwater Form highly resistant cysts  survive in frozen or dry lakes Store energy as oils  formation of petroleum  new biofuels?

Plant-Like Protists Phylum Euglenophyta - Euglenoids Unicellular, plant-like and animal-like: No cell walls, have protein pellicle Chloroplasts (if raised in presence of light) Eyespot sensitive to light Contractile vacuole Chlorophylls a and b, carotenoids Most live in freshwater, some in moist soil and animal digestive tracts