2. Plant Reproduction In Angiosperms (Flowering Plants)

3. I. Introduction to Seed Plants A. Gymnosperms: B. Angiosperms: Adaptations for terrestrial seed plant reproduction: fflowers or cones ttransfer of sperm by pollination pprotection of embryos in seeds Seed plants that bear unprotected seeds within the slots of cones Flowering plants that bear coated seeds within ovaries (fruit)

4. Sepals Outermost circle of floral parts Enclose the bud before it opens Protects the flower while it develops Petals Located just inside the sepals Often brightly colored to attract pollinators Stigma Style Ovary Sticky to collects pollen Supports the stigma contains one or more ovules Ovule Produces embryo sac (contains eggs) Pistil/Carpel Anther Filament Site of meiosis to produce sperm in pollen grains Supports the anther Stamen II. Structure of Flowers A. Flowers are reproductive organs that consist of 4 specialized leaves: sepals, petals, stamen and pistils/carpels

5. Sepals Immature Flower Parts

6. Sepal Petal

7. Filament Anther Stamen

8. It’s a bit dark in here. Nice.

9. Stigma Style Ovary Pistil

10. Ovary Ovule

11. 3 Sepals3 Petals 6 Stamen 1 Pistil

12. Pollen Ovary Embryo Sac Ovule

13. III. Life Cycle of Angiosperms A.The life cycle begins when a mature sporophyte (diploid plant) develops flowers.

14. B. Meiosis occurs in the anthers and ovaries to produce gametophytes. 1. Male Gametophyte: Pollen Grain Embryo Sac b) Contains: a) Produces/Stores Sperm Tube nucleus (n) Generative nucleus (n) 2. Female Gametophyte: a) Produces/Stores Eggs b) Contains: Egg nucleus (n) 2 polar nuclei (n)

18. Gymnosperm

19. Angiosperm

20. C. Pollination:pollen released from anther lands on stigma 1. Self- Pollination: pollen lands on the stigma of the same plant 2. Cross- Pollination: pollen lands on the stigma of a different plant * Pollen carried by gravity, wind, insects, birds, small animals, etc.

21. D. Fertilization 1.Pollen grain’s tube nucleus releases enzymes to “dig” a pollen tube through the style to the ovule

22. 2. Pollen grain’s generative nucleus divides once to produce 2 sperm, which travel down the pollen tube

23. 3. Double Fertilization: a) One sperm fertilizes the egg to produce a diploid embryo b) The other sperm fuses with the 2 polar (endosperm) nuclei to produce triploid (3n) endosperm.

24. 4. Endosperm = food supply for embryo a) Cotyledons (seed leaves) absorb some of the nutrients in endosperm to nourish the embryo during germination. *Monocot - *Dicot - plant with one cotyledon plant with two cotyledons

26. form from the ovule containing the fertilized embryo sac. ex. bean E. Seeds: 2. Seed Coat: 1. Plant embryo surrounded by a food supply surrounds and protects the embryo and keeps the seed contents from drying out

27. Angiosperm

28. F. Fruit & Seed Dispersal: 1. After fertilization, ovary walls thicken to form fruit. 2. Seeds dispersed by vectors ex. animals, wind, water * Seed coats cannot be digested. * Animals eat fruit and egest seeds elsewhere

32. G. Dormancy:Period when embryo is alive but not growing. H. Germination:Young plant sprouts from seed *germination won’t occur until conditions are suitable