1 / 24

Flowers and Reproduction

Flowers and Reproduction. Dr. Gough. Figure 09.07A: (a) The sepals of this rose form a tight covering over the rest of the flower as it develops, protecting the inner parts. Flower Structure. Ovary Position Protect ovary from pollinators. Fig. 9-28. Flower Structure.

thane-nielsen
Download Presentation

Flowers and Reproduction

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Flowers and Reproduction Dr. Gough

  2. Figure 09.07A: (a) The sepals of this rose form a tight covering over the rest of the flower as it develops, protecting the inner parts.

  3. Flower Structure • Ovary Position • Protect ovary from pollinators Fig. 9-28

  4. Flower Structure • Stem with leaf-like structures • Terminology • Pedicel and receptacle • Complete vs. incomplete flowers • Sepals (calyx) • Petals (corolla) • Stamens (androecium) • Carpels (gynoecium)

  5. Reproduction • Two forms of reproduction • Produce identical genetic copies • Produce genetically different offspring • What conditions favor which form? • How does sexual reproduction produce genetically different offspring? • Some plants reproduce both ways

  6. Asexual Reproduction • Many methods • Fragmentation • Rhizomes • Stolons

  7. Figure 09.02C: (c) All the trees in this photograph are a part of the same plant, each a sprout from a single root system.

  8. Sexual Reproduction • In angiosperms, requires flowers • Plant Life Cycle • Think of human/animal life cycle • Meiosis • Fertilization • Mitosis • More complicated in plants • “alternation of generations”

  9. Figure 09.13: This is the tip of a growing pollen tube. It was treated to make the nuclei fluoresce so that they can be found despite being so small. Courtesy of S. Muccifora

  10. Sexual Reproduction • Fertilization • Following pollination • Pollen tube growths through style to ovule opening • One sperm nucleus fertilizes egg • Second sperm nucleus migrates into central cell • Only in angiosperms • Becomes endosperm • “Double fertilization”

  11. Sexual Reproduction • Embryo and Seed Development • Zygote continues dividing, growing • Embryo • Radicle • Hypocotyl • Epicotyl • Monocotyledon • Dicotyledon

  12. Figure 09.19A: (a) This bean seed has begun germinating; the radicle has extended and will develop into a taproot.

  13. Figure 09.19C: (c) The small leaves present on the epicotyl are expanding during germination.

  14. Sexual Reproduction • Fruit Development • Fruit is a mature ovary

  15. Figure 09.21: In apples, the petals die and fall off after pollination.

  16. Figure 09.22B: (b) Coconuts in stores are usually just the endocarp and seed.

  17. Flower Structure and Cross-Pollination • Role of flowers in pollen and seed dispersal • Cross-pollination • Vs. self-pollination • Stamen and style maturation times • Stigma and pollen incompatibility

  18. Flower Structure and Cross-Pollination • Monoecious and dioecious species • Imperfect vs. perfect flowers • Monoecy • Dioecy Fig. 9-25

  19. Flower Structure and Cross-Pollination • Animal-pollinated flowers • Coevolution between plants and pollinators • Plant-insect pollination began about 120 mya • What traits were favored? • Some birds and bats pollinate too • Flower shape • Actinomorphic/regular vs. zygomorphic • Usually positive relationship, but cheaters on both sides

  20. Fruit Types and Seed Dispersal • More co-evolution! • Seed (fruit) dispersal agents • Gravity • Wind • Water • Animals • Often division of labor within fruit

More Related