Questions Do all seaweeds contain chlorophyll? Yes, though sometimes other pigments hide its green color. A diver is swimming under the ocean and finds a submerged, plant-like organism growing on the sea floor. It appears to have leaves and a stem, and it is held down by what appear to be roots. Is this organism definitely a true plant? No, it could be but it could be an alga.

Reproduction in Seaweeds New Terms to know Vegetative Reproduction = Asexual Reproduction Diploid = 2n (chromosomes come in pairs) Haploid = n (1/2 the number of chromosomes)

Alteration of Generation 1. Starts with diploid thallus. 2. Meiosis produces haploid spores. 3. Haploid spores becomes haploid thallus. 4. Haploid thallus forms gametes. 5. Fertilization of gametes produces diploid zygote. 6. Zygote grows into diploid thallus. Sporophyte generation to gametophyte generation   Alternates from asexual stage to sexual stage n 2n

Suppose a seaweed reproduces using the alteration of generations life cycle, with both generations having the same appearance. If you were looking at a population of these seaweeds, would the thalli most likely be all haploid, all diploid, or both? Both! Spores n Gametes 2n

Kingdom Fungi No Chlorophyll - no photosynthesis! Decomposers Some exist with algae SYMBIOTIC RELATIONSHIP Symbiosis- a close relationship between 2 species where at least one benefits The result of a fungus and an algae is a lichen Algae provide the food and fungus provides the support!

Lichen

Kingdom Plantae 3 groups to consider Sea grasses- completely marine Salt water marshes Mangroves True plants with true leaves, stems and roots

The Sea Grasses 45 species Have flowers, seeds, and pollen for reproduction Provide shelter and food for animals Roots absorb nutrients from soil and hold it in place Horizontal stems produce vertical leaves

Common seagrasses Eel grass Turtle grass

Saltwater marsh plants Terrestrial plants that tolerate salt water Only roots are submerged -only at high tide Cord grasses can remove excess salts

The mangroves Salt tolerant plants Tropics and subtropics- No Frost Can form dense forests Several kinds Red mangroves has prop roots to support it. Known as “Island Makers”- roots trap and hold sediment.