BIOL 1202 Chapter : Chapter 29 Plant Diversity 1
Document Summary
Chapter 29 plant diversity 1: how plants colonized land. Comparisons of nuclear and chloroplast genes point to close relationship between green algae and land plants. Durable polymer sporopollenin (tough outer covering of spores and pollen) found in land plants: prevents spores from drying out. Great opportunity for adaptation: sunlight unfiltered by water and plankton, abundance of co2, nutrient rich soil, few herbivores and pathogens. Four key traits in nearly all land plants: alternation of generations and multicellular, dependent embryos. ** meiosis- 2n ---> n, n: apical meristems, walled spores in sporangia, multicellular gametangia. In the diagram, which box represents reduction division from a diploid state to a haploid state: box a*** ---> meiosis, box b ---> mitosis, box c ---> fertilization, box a and b. Concept 29. 2: non vascular land plants (bryophytes) have life cycles dominated by gametophytes. Bryophytes are represented today by three phyla of small herbaceous (non woody) plants: liverworts, hornworts, mosses.
