Chapter 6: Multicellular Primary Producers (Seaweeds & Plants)

Using three specific examples explain the advantages that complexity and multicellularity give to macrophytes?

1) cell specialization 2) Ability to participate in both asexual and sexual reproduction 3) Allow the organism to be larger

Alternation of Generation

2 thalli

angiosperm

A flowering plant that produces seeds within a fruit Typically terrestrial Exception: Sea Grasses, Mangroves

Marine Angiosperm Adaptations

Ability to excrete excess salt out of their pores to prevent dehydration

Primary Producer

An autotroph, usually a photosynthetic organism. Collectively, autotrophs make up the trophic level of an ecosystem that ultimately supports all other levels.

Haploid

An organism or cell having only one complete set of chromosomes.

Mangrove

Angiosperm nursery for many species protect shorelines from erosion and hurricanes

Seagrasses

Angiosperm shallow ocean beds saline anaerobic environments

Cordgrasses

Angiosperm, Halophytes live in extremely saline environments excrete salt through pores

How are aquatic plants different from terrestrial plants?

Aquatic plants and algae photosynthesize from all parts of their being, not just their leaves. Aquatic plants do not have roots and do not require soil to grow. Aquatic plants can also be unicellular. Aquatic plants do not have a xylem or veins in their leaves to distribute water like terrestrial plants.

Advantages of Asexual reproduction

Easy/ Quick Does not require a partner

Advantages of Sexual Reproduction

Genetic variation within a population

Green Algae

Macrophytes: Chlorophyta unicellular or multicellular or colonial Habitat: Mostly freshwater Tropical-Temperate Complexity:Least Complex Distribution: North American Coasts Benthic, Autotrophic Photosynthetic Pigments: Chlorophyll Examples: Ulva (Sea Lettuce)

Brown Algae

Macrophytes: Phaeophyta multicellular Habitat: Mostly Marine- temperate and polar rocky coasts Complexity:Largest and Most Complex Distribution: Atlantic Coasts of N. America and Europe Planktonic, Heterotrophic Photosynthetic Pigments: chl a, chl c, and carotenoids like fucoxanthin Examples: Macrocysytis (Giant Kelp)

Red Algae

Macrophytes: Rhodophyta multicellular Habitat: Marine- Alaska- So.Cal and N. Atlantic Complexity: Less Complex than Brown, more complex than Green Distribution: Atlantic Coasts of N. America and Europe Planktonic, Heterotrophic Photosynthetic Pigments: chl a, chl d, carotenoids, and the pigments phycobilins, phycoerythrin, and phycocyanin. Examples: Porphyra (nori) Byproduct: Carageenan, Agar

Sporophyte Generation

Meiosis produces the spores Unfavorable environments Motile- zoospores

No Alternation of Generations

One multicellular life form Diploid life form produces haploid gametes (through meiosis) which will fuse to become a diploid life form (fertilization)

Macro Algae

Red (rhodophyta) brown (phaeophyta) green (chlorophyta)

Holdfast

Root-like structure used to anchor an organism to a substrate

Thallus

The body of a plant-like organism that is not divided into leaves, roots, or stems

How do alternation of generation and no alternation of generation life cycles differ?

This alternation of generations is a life cycle that includes both diploid and haploid multicellular stages The no alternation of generation life cycle does not have both multicellular stages

Pneumatocyst

air bladders that keep marine plant in the photic zone

Budding

also known as spore production, this type of asexual reproduction involves a bud or spore being produced and then dispersed that eventually grows into a new individual (Volvox)

Macrophytes

an aquatic plant that grows in or near water and is either emergent, submergent, or floating. In lakes and rivers they provide cover for fish and substrate for aquatic invertebrates, produce oxygen, and act as food for some fish and wildlife

Diploid

an organism or cell having two sets of chromosomes or twice the haploid number

Carageenan

emulsifier: cream cheese red algae

Fragmentation

fragment of thallus grows into new individual (Sargassum)

Gametophyte

haploid life form that forms the gametes

Sexual Reproduction

reproduction involving the formation and fusion of gametes. Involves alternation of generations in seaweeds

Asexual Reproduction

reproduction that takes place without the formation of gametes (eggs and sperm)

Algin

stabilizer and emulsifier in ice cream, cheese, jam, and thickener for shampoo and shaving cream brown algae

Stipe

stem-like portion of aquatic plants/alga

Blade

the typically flat, green part of a leaf

Unicellular photoautotrophs vs Multicellular algaes

unicelluar photoautotrphs= phytoplankton buoyant Multicellular algae= seaweed allows for cell specialization Kingdom protista

Agar

used in cosmetics and pharmaceuticals red algae