2. Chpt. 30 Evolution of Seed Plants

3. Seed Plants Gymnosperms – naked seedsGymnosperms – naked seeds Angiosperms – covered seedsAngiosperms – covered seeds

5. Life Cycle switch

6. Further Reduction in Gametophyte generation N

7. What is the trend???? Seed Plants:  gametophyte is surrounded by SPOROPHYTE  gametophyte nourished by sporophyte.  no water needed

8. What is the trend???? Seed Plants:  no environmental stress for the gametophyte.  no spores produced.  microscopic

10. Multi-cellular sporophyte embryo w/ a food supply

11. Origin of seeds:

12. First seed plants Gymnosperm: conifers –vascular –heterospory male vs. female gametophytes –seeds naked seeds (no fruit) –pollen contain male gametophyte –life cycle dominated by sporophyte stage coniferous trees you are familiar with are diploid –gametes protected from drought & UV radiation

13. Gymnosperm: conifers

14. Cones & naked seeds

15. male female sporangium & pollen pine embryo

16. Origin of angiosperms (flowering plants)

26. Flower Variations Perfect Flowers - have stamens and carpels.Perfect Flowers - have stamens and carpels. Imperfect Flowers - have stamens or carpels.Imperfect Flowers - have stamens or carpels. Staminate FlowerCarpellate Flower

28. SPOROPHY TE 2n

29. in anther : microspores form via. meiosis…

30. in ovary : Megaspores form, in the ovule, via. meiosis

31. in anther : microspores develop into male gametophytes which are pollen grains

32. MATURE POLLEN GRAIN Specialize cell wall outside Inside :Tube Nucleus (cell) : Generative Nucleus (cell) will divide and produce two sperm nuclei

33. pollen grains produce two cell types: sperm cells (2) pollen tube generative cell = tube cell =

34. in ovary : Megaspores form female gametophyte found in the ovule

35. Where does the female gametophyte develope Tissue that protects sporangium Area that gives rise to female gametophyte Develops into female gametophyte OVULE

36. Megaspore- inside ovule undergoes meiosis.

37. Megaspore nucleus- inside ovule then divides 3X mitotically:

38. produces a sac with 8 nuclei Multicellular gametophyte

39. 1 egg cell 2 polar nuclei 5 others Multicellular gametophyte

40. 1 X 2 X 3 X megasporesurviving mitosis eggpolar nuclei others

41. Pollen attaches to the stigma & pollen tube develops

42. Pollen Vectors Bees Flies Butterflies Moths Birds Beetles Bats Wind

43. fertilization

44. how fertilization????

45. 2 sperm fertilization into embryo sac

46.  * * double fertilization creates: endosperm & zygote

48. What happens after fertilization?

50. germination

53. D R O P in CO 2 -->

54. Cooler temps

55. Summary  Know the adaptations of seed plants.  Know examples, life cycles, and importances of the gymnosperms and angiosperms.

56. Any Questions??

58. Nonrenewabl e

59. mature sporophyte l two types of cones these hold the sporangi a

60. monoecio us = both sexes on one plant

61. (sporophyte) cones are clusters of sporophylls - “leaflike” structures

62. (sporophyte) meiosis - > produce haploid microspores… pollen

63. (sporophyte) Sporophyll - “leaflike” structures Pollen - inside sporphyll

64. (sporophyte) pollen Microsporangia -----> meiosis--> microgametophyte ---> pollen

65. Megaspore --> found inside scales.

66. Megaspore --> produces egg

67. egg Magasporangia ----> meiosis --> megaspores ---> egg

68. opening Pollination through micropyle

69. Meiosis produces 4 haploid cells. ONE becomes megaspore. This will become gametophyte

70. Archegonia develop (within gametophyte)

71. Sperm develops in the pollen, pollen tube extends to the gametophyte --> FERTILIZATION

72. ` embryo forms … Sporophyte