chapter 7 multicellular plants
Post on 18-Dec-2014
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Chapter 7
Multicellular Primary Producers
• Remember how much seaweed was in your household products…..– What were some of the product that contained
algae that you found in your home in Lab 2??
Seaweeds
• Most found attached to a substrate• Inhibit 2% of seafloor• Life in the inner continental shelf depend upon
seaweeds for food• Abiotic Factors most influential are– Light *****– Temp***** (most diverse in tropical waters)– Tidal exposure– Salinity– Availability of nutrients
Seaweed Structure
• Thallus-body• Lack vascular tissue -Do not have roots, stems,
or leaves• Holdfast -The structure that attaches the
seaweed to the substrate • Stipe-stem-like structure
Phylum Chlorophyta (green algae)
• Ecologically important – food source – Contribute to coral reef
formation– Some are invasive
• Caulerpa taxifolia – https://www.youtube.c
om/watch?v=aT4LY2KcOrs
Green algae structure/characteristics
• Most unicellular• Most are freshwater( we saw some out at
pond) • Contain chlorophylls a and b for
photosynthesis• Marine species have coenocytic thallus-
containing more than 1 nucleus– Occurs by cell growing nucleus divides but cell
never divides
Reproduction (draw pic in your reproductive box)
• Sexual • Gametes released from gametophyte 2 flagella• spores released from sporophyte-4 flagella
Representative species
• Halimeda• Mermans shaving brush
Phylum Rhodophyta (Red algae)
• Primarily marine• Most diverse among seaweeds• Not always red in color- can appear yellow to
black
Structure• Multicellular and less than 1 meter long• Wide variety of shapes and organization
among species• Chlorophylls a and d, pigments:
phycoerythrins and phycocyanins
Reproduction
• Can vary from simple to complex…but 2 unique features………..
1. Lack flagella on spores and gametes
2. 3 multicellular stages (2n)
1. Carpospore-unique to red algae-
2. Tetrasporophyte3. Cystocarp
Ecological Roles/ Representative Species
• Seasonal food source for urchins, mollusks, fish, and crustaceans
• Some grow on other plants or animals• Help form base of coral reef• Used in cosmetics for creamy foundations• Representative Species:– Porphyra- used as food in oriental dishes– Agar- used as a thickening agent in foods such as ice
cream, pudding, and salad dressings
Phaeophyta (brown algae)
• Mostly marine• Higher diversity than green
but less diverse than red• Size: from microscopic to
kelps (100 meters)• Chlorophylls a and c and
pigment fucoxanthin• Mostly in high latitudes• Large flat leaf-like blades with
bladders help buoy plant toward light
• Representative species Sargassum, Fucus
Reproduction
• Gametophyte is eliminated from life cycle (difference from Chlorophyta and
Rhodophyta)• Egg develops
root-like structures (rhizoids) after fertilization
Ecological role
• Habitats for a variety of marine life• Harvested for thickening agents used in
dentistry, cosmetic, and food industries• Previously iodine was extracted and put into
table salt (iodized salt) to prevent a goiter
Phylum Anthophyta
• Seagrasses, salt marsh plants, mangroves• Ecological Roles- Primary producers, habitats,
stabilizing sediments
Sea grasses (marine flowering plants)
• Related to lilies• Reproduce by pollination of seed; Male and
female flowers on separate plants contain pollen
• 12 genra– Genra native to Florida• Syringodium -manateegrass• Halophila-paddlegrass• Thalassia- turtlegrass• Ruppia- • Halodule- shoalgrass
Salt Marsh Plants• Adapted to high levels of salinity and tidal action• Found in estuaries – level of succession based on salinity and tidal tolerance• Species native to Jacksonville (will be responsible for these on the test!!!)
– Spartina Alternaflora– Batis Maritima– Spartina patens– Juncus– Salicornia virginica
Mangroves
• Found in south of St. Augustine to Key West• 3 genra local to Florida– Rhizophora mangle –red mangle-----prop roots– Avicennia germinans – black mangle---
pneumatophores– Laguncularia racemosa- white mangle
• Distinctive by their root system and pods
Mangrove reproduction
• Flowers pollinated by wind or bees• Embryo grows on the plant in a propagule
(similar to seed)• Propagule eventually falls from parent and is
carried by current until it settles and takes root
Black Mangrove
Red Mangrove
Red, White, and Black mangrove leaves
White Mangrove
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