Flowering Plants - Angiosperms

2. Flowering Plants - Angiosperms

3. Flowering Plants - Angiosperms • Largest group of Land Plants! • Most important economically! • Apomorphies: • Flowers • Carpels • Fruits • Double fertilization with triploid endosperm • Specialized conductive cells

4. Why have Angiosperms been so successful?

5. } modified leaves FlowersWhat is a flower? = Shoot system bearing modified leaves: Perianth Calyx (sepals) - green, protective Corolla (petals) - colored, attractant Stamens - male Carpels - female

6. pistil Fig. 30.7

7. Flower parts:

8. Flower pollination (transfer of pollen to ovule): Animal pollination Ancestral for Angiosperms Much moreefficient means of transporting pollen All Gymnosperms are wind pollinated (Some Angiosperms secondarily wind pollinated)

9. Strategy of animal pollination: Attractant Visual: large or brightly colored perianth Olfactory (smell): sweet or rotten (fetid) odor Reward Usually nectar or pollen (Rarely waxes, oils)

10. Pollination Mechanisms Insects Bees Butterflies/Moths Flies Birds Bats Water Wind

11. Bee-pollinated

12. Moth-pollinated

13. Fly-pollinated

14. Bird-pollinated

15. Bat-pollinated

16. Wind pollination in grasses

17. Phyllospadix torreyi Surf-Grass Water-pollinated

18. 2) CarpelsCarpel = conduplicate megasporophyll Conduplicate = folded Megasporophyll = “female leaf, bearing seeds” Carpel totally encloses ovules/seeds

19. Carpels can fuse together Gynoecium = all female parts Pistil = ovary + style + stigma Pistil can be one carpel or many

20. orange: 8 fused carpels carpel

21. Function of Carpel • Protects young seeds • Site of pollen germination- Can induce self-incompatibility reactions • Fruits

22. Self-incompatibility- Pollen will not germinate on genetically similar individuals- Promotes outcrossing

23. 3) FruitsFruit = mature ovary (plus accessory parts) Function: seed dispersal

24. Fruit types:dry- dispersed mechanically, by wind, water, etc. fleshy- dispersed by animals

25. 4) Double fertilization in Angiosperms Assignment: Study Figs. 38.2, 38.3, 38.5

26. Double fertilization in Angiosperms Pollen produces 2 sperm cells:

27. Double fertilization in Angiosperms Pollen produces 2 sperm cells: sperm (n) + egg (n) ----> zygote (2n) sperm (n) + 2 polar nuclei (n) ----> endosperm (3n)

28. Triploid endosperm is nutritive tissue in seeds of Angiosperms. Extra set of genes may help in:1) rapid development 2) increase genetic variation

29. Gymnosperms:- Fertilization occurs long after pollination - Seeds mature slowly (1-2 years) Angiosperms:- Fertilization occurs soon after pollination - Seeds produced rapidly - Selective advantage (e.g., annual herbs)

30. 5) Specialized conductive cells Most Angiosperms have vessels Specialized in having perforation plates vessel perforation plate

31. All Angiosperms have sieve tube members -with sieve plates: bigger pores in end walls big callose-lined pores

32. Angiosperms Vessels and sieve tube members more efficient in water / sugar conduction

33. Angiosperm Classification

34. 1 cotyledon 1 cotyledon coleoptile epicotyl epicotyl hypocotyl embryo radicle radicle coleorhiza seed coat MONOCOTS endosperm 2 cotyledons { epicotyl embryo hypocotyl radicle NON-MONOCOT Old classification: Dicots - 2 cotyledons (seed leaves) Monocots - 1 cotyledon

35. Monocots monophyletic

36. Monocot apomorphies

37. 1 cotyledon 1 cotyledon coleoptile epicotyl epicotyl hypocotyl embryo radicle radicle coleorhiza MONOCOTS Monocot apomorphies 1 cotyledon parallel venation stem an atactostele -many scattered vascular bundles (wood lost!)

38. Monocots include: Palms Orchids Irises Grasses, etc.

39. “Dicots” paraphyletic!

40. Features that defined “Dicots” are primitive (not apomorphies)

41. Eudicots monophyletic!

42. Eudicot apomorphy: Pollen tricolpate - 3 apertures A A A

43. All other Angiosperms: aperture Pollen has 1 aperture

44. Eudicots include most angiosperms: Roses Legumes Daisies Oaks, etc.