Plants reproduce through two alternating multicellular generations - the haploid gametophyte generation and the diploid sporophyte generation. In the gametophyte generation, haploid spores form gametophytes which produce gametes through mitosis. The gametes fuse to form a zygote, which undergoes mitosis to form the sporophyte generation. The sporophyte then undergoes meiosis to produce haploid spores, continuing the life cycle. Vascular plants have a dominant sporophyte generation, while nonvascular plants are dominated by the gametophyte generation. Angiosperms have an enclosed life cycle involving flowers, fruits, and seeds to protect and disperse their sporophy

1. Patterns of Reproduction in Plants

2. Purely Organic In The News

3. Alternate Generations of Plants Plant life cycle Two multicellular generations that alternate One phase includes sexual reproduction

4. Plant Life Cycles Diploid Usual complement of chromosome pairs Includes zygote & sporophyte Haploid One set of chromosomes only Includes spores, gametophyte, egg, & sperm

5. Gametophytes Haploid Haploid spores form gametophyte Form gametes by mitosis

6. Gamete Formation Eggs formed in archegonia Sperm produced in antheridium Fuse to form zygote

7. Sporophyte Zygote undergoes mitosis Multicellular sporophyte undergoes meiosis Spores often in cases called sporangia

8. One Generation Dominates Gametophyte in nonvascular plants Mosses Liverworts & hornwort Sporophyte in vascular plants Ferns Conifers Flowering plants

9. Nonvascular Plants Three phyla Bryophyta – mosses Hepatophyta – liverworts Anthocerophyta – hornwort Gametophyte nutritionally independent Sporophyte grows out of gametophyte

10. Vascular Plants Seedless vascular plants Whisk ferns Club mosses Horsetails Ferns Plants with naked seeds Conifers Cycads Ginkos Protected seeds Angiosperms

11. Seedless Vascular Plants Seeds contain sporophyte embryos & food Seedless plants compensate for no seed by being tied to favorable habitat Sporophyte is dominant stage

12. Moss Life cycle

13. Gymnosperms Exposed (naked) seeds Sporophyte generation dominates Includes conifers, cycads & ginkos

14. Pine Life Cycle

15. Angiosperms Protected seeds Flowering plants Largest number of plants

17. Flowers Organ for sexual reproduction Sepals = outer modified leaves Petals attract pollinators Male stamen Female pistil

18. Angiosperm Life Cycle

19. Pollination Method to combine egg & sperm Wind pollination Gymnosperms Some angiosperms like grasses

20. Pollination Insect & animal pollination Pollen carried from one flower to another Common in many angiosperms Some are self pollinated

21. Seed Development Zygote is plant embryo Endosperm From other sperm nuclei Feeds embryo Embryo develops cotyledons (seed leaves) Monocot = single cotyledon Dicot = double cotyledon

22. Fruit Mature ovary Seeds, tissues, and coverings Fruits may allow for animal dispersal

23. Seed Dispersal Methods Animals, wind, & water

24. Germination Begins when seed takes up water Initially uses stored food of seed Begins to sprout

25. Monocots Vs. Dicots Differ in recognizable features Dicots – food stored in cotyledons Monocots – food stored in endosperm

26. Seedling Development Radicle First portion to emerge Anchors seedling Epicotyl Portion of shoot above cotyledon

27. Seedling Development Coleoptile Sheath protecting new leaves Hypocotyl Shoot below cotyledens

28. Vegetative Propogation Asexual reproduction New plant develops from portion of parent Rhizomes = underground stems Stolons = above ground stems

29. Vegetative Propogation Leaves can produce new plants

30. Cell Culture of Plants Plant production from a single cell Produces genetic clones