Lecture #10- Algae and Spore Formers P 132-141, A closer look 9.2

1. Algae: Grass of the Sea
   1. Characteristics
      1. mostly photosynthetic
      2. no cuticle
      3. single cells to very large seaweeds
      4. No vascular system, roots, stems, leaves
      5. Reproduce both sexually and asexually
   2. Red Algae-oldest eukaryotes
   3. Diatoms-Golden Brown Algae-largest group-Silica in cell wall
   4. Dinoflagellates
   5. Brown Algae-Kelp
   6. Green algae-second largest group-gave rise to higher plants
   7. Life cycle
   8. Significance to humans
      1. base of the food chain-primary producers
      2. can be harmful
      3. commercial value-Algin and Carrageenan, iodine, food
2. Plants Move on to the Land
   1. Challenges to living on the land
      1. Get water-ultimately roots
      2. Keep water-cuticle, protect gametes
      3. Get energy-grow tall so develop support and transport tissues
      4. Photosynthesis-water trade off; stomates
      5. Multicellular
   2. Alternation of generations
3. The First Land Plants
   1. Bryophytes-Mosses
      1. Cuticle, multicellular gamegangia, stomata
      2. No vascular tissue
      3. Live in very moist environments
      4. Life Cycle-Gametophyte dominant-produces gametes
      5. Sporophyte grows on gametophyte-produces spores
      6. Significance of Mosses-food for animals Fuel, soil additive
   2. Ferns- First vascular plants-
      1. Fossils 390 million years ago, dominant plants
      2. Advancements-vascular tissue, dominant sporophyte
      3. Life cycle- sporangia underside of fronds(leaves)
      4. Independent gametophyte-prothallus
      5. Significance-Present day coal, oil, ornamental plants, peat.