Macroalgae Flashcards
divisions of seaweed
- green
- brown
- red
Three features
- multi-cellular
- secured to the bottom
- complex life histories
Ecology of seaweeds
- shallow waters
- provide shelter/habitat
- contribute to primary production
How do plants and Macroalgae differ
lack vascular tissue, leaves stems and roots
Stipe
stem: flexible
Blade
photosynthetic, no veins, no stomata
Pneumatocyst
gas filled bladder, floats
Holdfast
attaches to rocky areas
Morphology of seaweed
stipe, blade, pneumatocyst, holdfast
Green Algae characteristics
- green pigments
- starch food reserves
- cellulose cell wall
- unicellular, some multi
- structure: simple filament -> flat sheets
What is Ulva
Sea lettuce: green algae
Red Algae characteristics
- division Rhodophyte
- red color: phycobilin
- starch used as food storage
- cell wall made of agar, carrageenan, cellulose
What are Red Algae’s cell walls made of?
Agar, carrageenan, cellulose
Brown Algae characteristics
- brown color
- Laminarin and oil used as food reserves
- cell wall made of cellulose and alginates
- structurally complex
- commonly found on rocks
What division is brown algae?
Phaeophyta
Kelps size
up to 100m tall
50 cm/day growth
Life History #1?
most common, greens & browns
- > alternate between two stages
1. sporophyte: 2n
2. gametophyte: 1n
Life History #2?
3 steps
- sporophyte: 2n
- gametophyte: 1n
- carposporophyte: 2n
Life History #3?
no alternation of generations like animals
- diploid: 2n
- haploid: 1n
Life History #4?
no alternation of generations
- diploid: 2n (zygot)
- haploid: 1n (spore)
Initiation of sexual reproduction
caused by nutrients, temp, day length
ecological importance of macroalgae
habitat formation, intertidal and subtidal importance
economic importance
wild and cultured
industrial products
food
biofuel
Uses for Carageenans?
dairy products
Uses for Algin?
ice cream, cheese, baking, rubber
Uses for Agar?
jellies, low calorie foods
