Photosynthetic Protists (Plant-like)

Unicellular Motile Contain chlorophyll (for photosynthesis) Most contain flagella Commonly called Algae

Water absorbs light’s energy too Chlorophyll: Green pigments found in chloroplasts that help absorb energy from light Accessory Pigments: light- absorbing compounds found in photosynthetic organisms Give algae its colour Water absorbs light’s energy too

Over time, algae has adapted to different environments, and has evolved different forms of chlorophyll

Types of Plant-Like Protists: Euglenophyta Pyrrophyta Algae Euglena Pyrrophyta Dinoflagellates Algae Chlorophyta, Phaeophyta, Chrysophyta, Rhodophyta

Euglenophyta have chloroplasts Some grow in the absence of light They are known to lose their chloroplasts and become heterotrophic Euglena can change shape using euglenoid movement

Red eye spot helps euglena find the brightest areas 2 flagella Possess a tough, intricate membrane = Pellicle Reproduce by Binary Fission Very similar to zooflagellates

Dinoflagellates (Pyrrophyta) Luminescent (give off light) Photosynthetic and heterotrophic Reproduce by Binary Fission Dinoflagellates sometimes bloom in concentrations of more than a million cells per mL They can produce toxins (red tide)

Algal Blooms: An enormous mass of algae Algal blooms can be very harmful Deplete water of nutrients and kill cells Decomposition of dead algae can rob water of oxygen

Algae Contain chlorophyll, but they may also contain other pigments that mask the chlorophyll colour Anchoring devices = holdfasts Flexible stems = Stipes Maximize their exposure to light = blades Store gases for buoyancy = bladder

Grouped according to colour and biochemical differences Green, golden brown, brown, and red

A .Green Algae (Chlorophyta) Cell walls made of cellulose Live in fresh and marine water Believed to be closely related to the first plants Green, orange, red, rust colours

Examples of Green Algae Chlamydomonas (unicellular) Produce zoospores Two small contractile vacuoles help maintain water balance

Volvox (Colonial) When the colony moves, cells on 1 side pull with their flagella

Spirogyra (Filamentous – long thread- like colonies) Surfaces of ponds and streams

Ulva (multicellular) Sea Lettuce

Green Algae can undergo alternation of generations Switch back and forth between haploid and diploid

B. Brown Algae (Phaeophyta) Small and Large (Seaweeds and kelps) Contain the pigment fucoxanthin Grow in cool, shallow coastal waters Largest known alga = giant kelp Provide food and habitat for marine organisms Source of algin (gives ice cream, sherbet, cream cheese a stable smooth consistency)

Have gold chloroplasts Cell walls contain pectin (carbohydrate) C. Golden Brown Algae (Chrysophyta) Have gold chloroplasts Cell walls contain pectin (carbohydrate) Store food in the form of oil

Diatoms (Bacillariophyta) Shaped like a petri dish Cell wall has an outer layer of silica (ingredient in glass) Produce a major portion of earth’s oxygen Most abundant

D. Red Algae (Rhodophyta) Can live in deep water Accessory pigment phycobilin absorbs blue wavelengths of light (allows red algae to live in deep oceans) Material in cell walls is a source of agar used commercially to make capsules for vitamins and drugs, dental impressions, cosmetics, anti-drying agent for baked goods (jelly) Coralline algae play an important role in coral reef formation