•Nearly 75% of the world’s oxygen
produced by algae •One of the major food source of
marine ecosystems •Eukaryotic, photosynthetic
(autotrophs)
CLASSIFICATION OF ALGAE
•SEVEN PHYLUM BASED ON–COLOR–TYPE OF CHLOROPHYLL–FOOD-STORAGE SUBSTANCE–CELL WALL COMPOSITION
Chlorophyta: Green Algae
•“Green algae”
• •Mostly found in fresh water
• •Contain chlorophylls a and b
• •Store energy as starch (carbohydrate)
• •Cell walls made of cellulose
Genus: Volvox
•Consists of many Chlamydomonas-like
•cells bound in
•a colony
•Each cell has two flagella
Phaeophyta: Brown Algae
•“Brown algae”
• •Primarily marine algae
• •No unicellular or colonial forms
• •Contain chlorophyll c and brown pigment
•fucoxanthin
• •Range in size from microscopic to kelps
•over 50 meters long
Genus: Fucus
• •Also called “rockweed”
• •Typically attaches to rocks in intertidal
•zone
• •Outer surface covered by gelatinous sheath
• •Tips of branches (called conceptacles)
•may be swollen and contain reproductive
•structures – oogonia (female, produce
•eggs) and antheridia (male, produce
•sperm(
Rhodophyta: Red Algae
•“ •Red algae”• •Contain chlorophyll d and red pigments•)phycobilins(• •Mainly multicellular• •Typically in warm marine water• •Can be attached, free-floating,
filamentous,•or parenchymatous (fleshy)
Chrysophyta
•“Diatoms”
• •Unicellular
• •Contain chlorophylls a and c, as well as
•xanthophyll pigments (golden-brown)
• •Have hard cell wall made of silicon dioxide
Euglenophyta
• •Unicellular
• •Motile (two flagella)
• •Contain chlorophylls a and b
• •Mainly freshwater algae
• •Main cell wall component: protein (flexible)
• •Asexual reproduction
Genus Euglena
Unicellular