Phaeophyta (Brown Algae)

Question 1

Habitat

Answer 1

Marine waters
On rocks in cool waters

Question 2

Examples

Answer 2

Kelps
Rockweeds
Sargassum
Fucus

Question 3

Body Structure

Answer 3

Thallus - entire body

Holdfast - rootlike structure at base; provides anchorage

Stipe - Stalk or stem-like structure

Blade (lamina)- frond; leaf like structure

Air bladder (pneumatocyst)- has O2; provides buoyancy for light harvesting.

Question 4

Pigment

Answer 4

Chlorphyll

Fucoxanthin (yellow-brown carotenoid)

Question 5

Storage product

Answer 5

Laminarin

Question 6

Cell Wall Component

Answer 6

Alginates

Question 7

Do they produce Motile zoospores and anthrozoids?

Answer 7

Yes they do

flagella inserted laterally
Anisokont (unequal in size)

Question 8

Importance of Kelp Forests

Answer 8

• Shelter for marine life (Garbaldi, scallops, seals, sea otters, abalones, sharks)

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Question 9

Economic importance of Brown Algae

Answer 9

• Fertilizer
• Cattle feed
• Food (sea noodles)
• Dietary supplement
• Teeth Mold

Question 10

Cell Wall Structure

Answer 10

Composed of 2 layers
- Cellulose (structural skeleton)
- Alginic acid & Fucoidin (Amorphous component)

Question 11

Fucus is also known as what?

Answer 11

Bladderwack

Question 12

Diplontic Life Cycle: Fucus

Answer 12

–>Tips of mature Fucus develop receptacles, which have numerous tiny conceptacles.

–> Sperms and eggs are produced in these conceptacles.

–> Immature oogonia and antheridia undergo meiosis and produce mature sperm cells and egg cells.

–> Pheromone is released into the water by egg and sperm is attracted to it.

–> fertilization occurs and a 2n zygote is produced.

Question 13

Is the Sargassum plant body diploid?

Answer 13

Yes