Algae

•Nearly 75% of the world’s oxygen

produced by algae •One of the major food source of

marine ecosystems •Eukaryotic, photosynthetic

(autotrophs)

STRUCTURE

•Four types of algae–Unicellular

–Colonial

–Filamentous

–multicellular

THE TYPE OF ALGAE

UnicellularColonial

Filamentousmulticellular

CLASSIFICATION OF ALGAE

•SEVEN PHYLUM BASED ON–COLOR–TYPE OF CHLOROPHYLL–FOOD-STORAGE SUBSTANCE–CELL WALL COMPOSITION

Algal Taxonomy

•In today’s lab, we will look at algal groups:

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: Chlamydomonas

•Motile, unicellular algae

Genus: Spirogyra

•Filamentous

http://www.sharnoffphotos.com/nature/algae_cyanobacteria/alg_img/spirogyra_cellswtmk.jpg

Genus: Volvox

•Consists of many Chlamydomonas-like

•cells bound in

•a colony

•Each cell has two flagella

http://images.google.com.sa/imgres?imgurl=http://www.arab-box.com/photos/00062/kcactxj67cll.jpg&imgrefurl=http://www.etsabya.com/forum.php%3Faction%3Dview%26id%3D491&usg=__11j50TcintSw3FHI1EV0GbnFbko=&h=437&w=605&sz=81&hl=ar&start=9&um=1&itbs=1&tbnid=MpFQ7IiMtaVeVM:&tbnh=98&tbnw=135&prev=/images%3Fq%3DVolvox%26um%3D1%26hl%3Dar%26safe%3Dactive%26sa%3DG%26rlz%3D1R2RNTN_enSA355%26ndsp%3D18%26tbs%3Disch:1

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

•Diatoms can be:

• •Pennate (bilateral

•symmetry(

•Or

• •Centrate (round,

•radial symmetry(

Euglenophyta

• •Unicellular

• •Motile (two flagella)

• •Contain chlorophylls a and b

• •Mainly freshwater algae

• •Main cell wall component: protein (flexible)

• •Asexual reproduction

Genus Euglena

Unicellular