1. Sexual Life cycles Plant structure and Phylogeny The Angiosperms

2. Outline Brief review 9. ALTERNATION OF GENERATIONS 8. PLANT EVOLUTION 7. ANGIOSPERM LIFE HIST.

3. Define sex cell.

4. All life is organized into 3 domains 2 Domains of prokaryotes, 1 of all eukaryotes Bacteria & Archaea- prokaryotic Eukaryota- Includes all 4 eukaryotic kingdoms: protista, animalia, plantae, fungi

5. Most of the many Eukaryotic species reproduce sexually

6. Despite an inherent twofold cost, higher species reproduce sexually Sexually reproducing species must have 2 offspring to “break even” 2 offspring from an asexually reproducing species doubles the population

7. Animal species alternate between diploid (mitotic) and haploid (meiotic) In animals, only the diploid stage is multicellular

8. Sexual life cycle of Animals gametic or diplontic - meiosis forms gametes, no spores - mainly like a sporophyte (2n) - produce gametes (1n) via meiosis - fertilization results in zygote (2n) - sporophyte grows via mitosis

9. Schematic gametic life cycle Sporophyte 

10. Many fungi work the opposite way zygotic or haplontic - zygote undergoes meiosis - mainly like a gametophyte (1n) - produce gametes (1n) via mitosis - fertiliz. results in zygote (2n) - produce spores (1n) via meiosis - gametophyte grows via mitosis

11. Most plants have two multicellular life cycle stages- gametophyte and sporophyte plants - sporic or diplohaplontic - alternate sporo- & gametophyte - meiosis forms spores - sporophytes (2n) dominate - produce spores (1n) via meiosis - gametophyte (1n) develops inside cone/flower via mitosis - prod. gametes (1n) via mitosis - fertiliz. results in zygote (2n) - sporophyte grows via mitosis

12. 8. PLANT EVOLUTION

13. Plant phylogeny

14. The Phylum Bryophyta includes liverworts and mosses Simplest terrestrial plants- avascular evolve multicell. & terrestrial - adapt to gravity, so small/low - no roots, rhizoids only anchor -sperm needs H2O to fertilize ova

15. In mosses, the sporophyte and gametophyte are similar in size

16. Ferns are vascular plants ferns (Phylum Pterophyta) evolve vasculature (vessels), allows fronds to grow large - true roots absorb H2O, minerals - no seeds, sperm still needs H2O

17. The gametophyte is smaller in the fern life cycle

18. The gametophyte nurtures the young sporophyte

19. Conifers are the prototypical gymnosperm gymnosperms (Phy. Coniferophyta) - evergreen needles reduce evap. ova in larger female cones sperm in pollen grains from male cones, dispersed by wind no fruit, naked seeds protect + provide nutrients to embryo

20. Gymnosperms include cycads & ginkoes

21. Gymnosperms have no flowers or fruits Mostly wind- pollinated The most massive indiviual living things- Giant sequoia

22. The tallest and most massive- here in CA

23. Male & Female Gametophytes are greatly reduced in gymnosperms

24. Angiosperms are flowering plants angiosperms (Phylum Anthophyta) - deciduous leaves drop off in winter, surv. low temp/H2O flowers attract animal pollinators with color-smell-nectar, more efficient for fertilization endosperm in seeds stores nutrients, esp. in grains/nuts fruit attracts animals to disperse & fertilize seeds, reduces comp.

25. Basic (monoecious) Flower structure

26. The male angiosperm gametophyte is even smaller inside anthers - meiosis prod. microspore (1n) - becomes the pollen grain = male gametophyte (1n) - with 2 sperm cells + tube cell

27. The female gametophyte houses the seed inside carpels - meiosis prod. megaspore (1n) becomes the ovary = female gametophyte (1n) = ovum + central cell (n+n)

28. Pollination pollination - pollen grain to stigma - tube cell grows pollen tube to reach ovary double fertilization - 1st sperm cell (1n) + ovum (1n) = zygote (2n sporophyte)

29. The seed is a capsule containing a plant embryo - 2nd sperm cell + central cell (n+n) = endosperm (3n, food in seed) seed - seed coat around endosperm - zygote grows into embryo via mitosis - ovary around seed becomes fruit

30. The plant embryo is already formed embryo - epicotyl becomes shoot - hypocotyl becomes root - cotyledons becomes leaves

31. Plant phylogeny

32. 6. MONOCOTS VS. DICOTS angiosperms - flowering plants - divided into 2 major groups monocots - corn, grasses - 1 cotyledon (embryonic leaf) - narrow leaves with parallel veins - flower parts in 3’s, fibrous roots - vascular bundles scattered, primary growth only dicots - most other angiosperms - 2 cotyledons absorb endosperm - broad leaves with network veins - flower parts in 4 or 5’s, taproot - vasc. bundles arranged in ring, secondary growth possible

33. Monocots vs. Dicots