1. Chapter 38 Angiosperm Reproduction

2. Angiosperms have 3 unique eatures: Angiosperms have 3 unique Features: 1. F 1. Flowers 2. F 2. Fruits F 3. Double Fertilization

4. Flower Structure Reproductive shoots Flower organs: 1.Sepal – leaflike, protect flower bud 2.Petal – modified leaves, attract pollinators 3.Stamen – ♂ reproductive organ  anther + filament 4.Carpel – ♀ reproductive organ  stigma + style + ovary Flower attached to stem at receptacle Pollination by wind, insects, birds

5. NameStructureFunction Sepals Little green leaflets attached to receptacle Protect the buds PetalsBrightly colored, 2 nd whorlAttract insects & other pollinators StamenAnther + filament ♂ Reproductive organ FilamentThin stalkSupport anther AntherTerminal end of filament Contains chambers to develop male gametophyte (pollen) CarpelStigma + style + ovary ♀ Reproductive organ StigmaSticky end of style“landing platform” for pollen Style Slender neck supporting stigma, leads to ovary Support stigma and pollen tubes OvariesSwollen lower portion of carpelDevelopment of ovules

6. Bilateral symmetry (orchid) SYMMETRY OVARY LOCATIONFLORAL DISTRIBUTION Lupine inflorescence Superior ovary Inferior ovary Sunflower inflorescence Semi-inferior ovary Sepal Fused petals Radial symmetry (daffodil)

7. REPRODUCTIVE VARIATIONS Maize, a monoecious species Dioecious Sagittaria latifolia (common arrowhead)

8. Pollination: transfer pollen from anther to stigma Pollen tube grows down into ovary for 2 sperm to travel to egg

9. Seed Double Fertilization ◦ The union of two sperm cells with different nuclei of the embryo sac. Makes the embryo and the endosperm Endosperm ◦ Food storing tissue of the seed.

10. Some plants are self-pollinated Cross-pollinated plants: ◦ Self-incompatibility: plant rejects own pollen or closely related plant ◦ Maximize genetic variation Stigma Pin flower Anther with pollen Thrum flower “Pin” and “thrum” flower types reduce self-fertilization

11. Seeds and Eggs Seeds are plant products which encloses the embryo with a hard coat and food supplies. Eggs are animal products which enclose an animal embryo with a hard or leathery shell and food supply. Eggs are similar to seeds because they protect the embryo while allowing gas exchange

12. From Ovule to Seed After Double Fertilization, each ovule develops into a seed. These seeds carry enough food and supplies until germination period. Seeds sinks down because the Endosperm is filled with the heavy supplies. Cotyledons swell to show that the Endosperm is filled with nourishment.

13. Endosperm An example of liquid Endosperm are the coconut milk. An example of solid Endosperm is the coconut meat itself. Also the white puff inside the popcorn is also the endosperm. Seeds carry endosperms until they are mature enough

14. The development of a plant embryo

15. Fruit Egg cell plant embryo Egg cell  plant embryo Ovules seeds Ovules inside ovary  seeds ovary fruit Ripe ovary  fruit Fruit protects enclosed seed(s) Aids in dispersal by water, wind, or animals

16. Types of Fruit

17. Seeds ******** Mature seed  dormancy (resting)  Low metabolic rate  Growth & development suspended  Resumes growth when environmental conditions suitable for germination

18. Seed Structure

21. Germination Seed take up water (imbibition)  trigger metabolic changes to begin growth 1.Root develops 2.Shoot tip emerges above ground  Stimulated by light 3.Foliage leaves expand & turn green  photosynthesis Very hazardous for plants due to vulnerability  Predators, parasites, wind

22. The first organ to emerge from the germinating seed is the radicle, the embryonic root. The first organ ◦ Next, the shoot tip must break through the soil surface. ◦ In garden beans and many other dicots, a hook forms in the hypocotyl, and growth pushes it aboveground. ◦ Stimulated by light, the hypocotyl straightens, raising the cotyledons and epicotyl.

23. Seed Germination

24. Seed to Seedling http://students.usm.maine.edu/deidre.rice/_ILLUS_ILT_T630888A.GIF

25. Sexual Asexual (Vegetative Reproduction) Flower  Seeds Runners, bulbs, grafts, cuttings vegetative (grass), fragmentation, test-tube cloning Genetic diversityClones More complex & hazardous for seedlings Simpler (no pollinator needed) Advantage in unstable environments Suited for stable environments Plant Reproduction

26. Asexual reproduction in aspen trees

27. Just a few parenchyma cells from a carrot gave rise to this callus, a mass of undifferentiated cells. The callus differentiates into an entire plant, with leaves, stems, and roots. Test-tube cloning of carrots

28. Humans Modify Crops Artificial selection of plants for breeding Plant Biotechnology: ◦ Genetically modified organisms  “Golden Rice”: engineered to produce beta- carotene (Vit. A)  Bt corn: transgenic – expresses Bt (bacteria) gene  produces protein toxic to insects ◦ Biofuels – reduce CO 2 emissions  Biodiesel: vegetable oils  Bioethanol: convert cellulose into ethanol

29. ♥ The seed of knowledge has sprouted..

30. ♥ Plant yourself in that chair… 1 more PPT to go!!!!!!