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Chapter 22: Plant Diversity. Comparison of Water and Land as Habitats for Plants. Adaptations of Land Plants to Terrestrial Environments. Differences Between Bryophyta and Tracheophyta. A. Metaphyta : Plant Kingdom. 1. Bryophyta (Phylum)
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A. Metaphyta: Plant Kingdom 1. Bryophyta (Phylum) • Simpler plants; lack vascular system (transport tubes such as xylem & phloem) • Depend on H2O to a greater extent than vascular plants Ex: mosses & liverworts
2. Tracheophyta (Phylum) • Higher plants • 3 main groups possess water vascular system, so LESS DEPENDENT ON H2O mosses (evolutionary advantage) 1. P. Pterophyta(ferns)sperm require water for fertilization 2. Gymnosperms/ conifers (cone-bearing) most ancient seed plants - POLLEN TUBE carries sperm- adaptation for terrestrial life 3. Angiosperms/ flowering plants POLLEN TUBE carries sperm - Adaptation for terrestrial life/ *life cycle
B. Processes Essential to Sexual Reproduction 1. Meiotic Cell Division reduces species chromosome number by ½haploid gametes 2. Fertilization restores species chromosome number (egg & sperm nuclei fuse- forms zygote) • Haploid (n) – cell has one member of each pair of chromosomes • Diploid (2n) – cell has both members of each chromosome pair
C. Reproduction in Mosses & Ferns • Alternation of Generations life cycle in which a spore producing plant (sporophyte) alternates with a gamete producing plant (gametophyte) a. Sexual reproduction by a gametophyte alternates with… b. Asexual reproduction by a sporophyte • Mosses common moss plant is the gametophyte • Ferns common fern plant is the sporophyte NOTE: * Review life cycles handout * Life cycles dependent upon water for fertilization * Habitat restricted/limited by water
Plant Life Cycle • Have 2 alternating phases known as “Alternation of Generations” 1. diploid phase (2N) sporophyte/ spore-producing plant 2. haploid phase (N) gametophyte/ gamete-producing plant)
Fern Life Cycle Prothallus- gametophyte
D. Alternation of Generations (Plant Reproduction) 1. What are the generations?
Cont. Alternation of Generations • Which plants have ONLY ONE kind of gametophyte and which plants have TWO KINDS of gametophytes Can you tell why??? • FERNSONE gametophyte --- Has both antheridia AND archegonia • MOSS TWO gametophytes --- Antheridia and archegonium on separate leaf-like stalks • FLOWERS TWO gametophytes --- Microscopic pollen and ovule
Cont. Alternation of Generations 3. What alternates? • Processes Mitosis/ meiosis/ fertilization • Nutrition Dependent (hetertrophic)/ independent (autotrophic) • Chromosome # Diploid/ haploid • Size Dominant (large/ conspicuous)/ not dominant (smaller/ inconspicuous) • Duration Most of life cycle/ short time period • Sex Asexual (spores)/ sexual (gametes)
4. In plant reproduction, what stage is between the diploid parent plant and the diploid young offspring plant? • Haploid gametophyte stage 5.In plant reproduction, what cell division process is used to make the gametes? • Mitosis- gametophytes are haploid
SUMMARY OF MAJOR PLANT CHARACTERISTICS (METAPHYTA)(Autotrophic, multicellular, cell wall of cellulose