Plant Reproduction and Plant Diversity II

1. Plant Reproduction and Plant Diversity II Chapter 30/38

2. Seed plants - vascular plants that produce seeds. • 3 adaptations that seed plants have: • 1Gametophyte more reduced. • 2Seed evolved. • 3Pollen evolved.

4. Gametophytes of seed plants almost invisible. • Gametophytes still exist - plants can destroy themselves at this stage if there something wrong with plant.

5. http://www.palaeos.com/Plants/Images/PhyscomitrellaRhizoids.jpghttp://www.palaeos.com/Plants/Images/PhyscomitrellaRhizoids.jpg

6. Seed - sporophyte embryo packaged with food supply within protective coat. • Seed plants produce 2 different types of sporangia - produce 2 different types of spores: megaspores (female gametophyte) and microspores. • Gametophytes stay in sporophyte as it develops.

7. http://botit.botany.wisc.edu/images/130/Early_development/Bean/bean_seed_2_MC.low.jpghttp://botit.botany.wisc.edu/images/130/Early_development/Bean/bean_seed_2_MC.low.jpg

8. Ovule - integuments (part protective covering), megaspore, and megasporangium. • Female gametophyte develops inside megaspore; produces 1 + egg cells. • Fertilized egg develops into sporophyte embryo. • Whole ovule develops into seed.

10. Microspores (pollen) – light, carried through air. • Pollen will create pollen tube - allow sperm to travel down into female gametophyte. • 2 groups of seed plants: gymnosperms and angiosperms.

11. http://www.hepafilters.com/images/pollen.gif

12. Gymnosperms • 4 phyla of gymnosperms still around. • Phylum Ginkgophyta contains only Ginkgo biloba.

14. Phylum Cycadophyta - cycads - look like palm trees. • Phylum Gnetophyta - 3 different types of plants (ephedra) • Phylum Coniferophyta - largest phyla - conifers - from reproductive structure, cone.

22. Conifers • Conifers are evergreen - keep leaves all year long. • Needles help in dry conditions. • Conifers include pines, firs, spruces, larches, yews, junipers, cedars, cypresses, and redwoods.

23. http://www.cambridge2000.com/gallery/images/P3075134.jpg

24. Life cycle of gymnosperms • Conifers - heterosporous (develop male and female gametophytes) • Produce pollen cones and ovule cones. • During pollination, pollen falls on ovule. • Creates pollen tube that digests through megaspore.

25. http://cache.eb.com/eb/image?id=62941&rendTypeId=4

26. Megaspore, now fertilized, goes through meiosis to produce 4 haploid cells. • 1 cell turns into female gametophyte, others (archegonia) will develop within gametophyte.

28. Angiosperms • Angiosperms - flowering plants - produce flowers, fruit. • Phylum Anthophyta - all angiosperms. • Divided into 2 groups: monocots and dicots. • Monocots - leaves with parallel veins, dicots have netlike venation.

30. Angiosperms - long tracheids - help transport water, support plant. • Flower specialized for reproduction. • Most angiosperms rely on pollination through animals; grasses - random chance.

32. Flower - specialized shoot - 4 circles of modified leaves: sepals, petals, stamens, and carpals. • Sepals - base of flower - modified leaves that enclose flower before it opens. • Petals lie inside ring of sepals - usually colorful in animal pollinated plants.

34. Male organ - stamen - thin, stalk-like filament with sac at top. • Anther - produces haploid spores that develop into pollen grains. • Female organ - pistil - contains 3 parts: stigma, style, ovary.

35. http://img.sparknotes.com/figures/B/b1ab5bb87aee74a86fdae78ed564e663/flower.gifhttp://img.sparknotes.com/figures/B/b1ab5bb87aee74a86fdae78ed564e663/flower.gif

36. Stigma - sticky top part of flower which extends beyond flower, catches pollen. • Style connects stigma to ovary at base of pistil which allows sperm to reach ovules. • Ovary - enlarged area at base of pistil - contains one or more ovules. • Entire structure - carpal. • Ovule contains egg nucleus.

37. http://park.org/Taiwan/Culture/Arts/flowers/religious/LB210302g2.jpghttp://park.org/Taiwan/Culture/Arts/flowers/religious/LB210302g2.jpg

38. Fruit - mature ovary. • As seeds develop from ovules after fertilization - wall of ovary thickens to form fruit. • Fruit helps protect seeds while they disperse. • Some fruits, dandelion, modified to catch wind. • Burrs that stick to animals - fruits.

41. Fruit develops after pollination triggers hormonal changes - cause ovarian growth. • Wall of ovary becomes pericarp (thickened wall of fruit) • If flower not pollinated - fruit will not develop. • 3 different types of fruits.

42. http://www.simplyclassicfruitbaskets.com/pic/fruit_festival_home.jpghttp://www.simplyclassicfruitbaskets.com/pic/fruit_festival_home.jpg

43. Simple fruits come from single ovary (cherries) • Aggregate fruit (blackberry) - single flower with several carpals. • Multiple fruit (pineapple) develops tightly clustered group of flowers.

45. Ovules - contain female gametophyte, embryo sac. • Angiosperm life cycle starts with mature flower on sporophyte plant and ends with germinating seed.

46. http://www.lclark.edu/~seavey/bio210/flower_dwg_ovules_pjt.gifhttp://www.lclark.edu/~seavey/bio210/flower_dwg_ovules_pjt.gif

47. Anthers of flower produce microspores that form male gametophytes (pollen). • Ovules produce megaspores that form female gametophytes (embryo sacs). • After its release from anther, pollen carried to sticky stigma of carpal. • Plants can self-pollinate; cross-pollination better.

48. http://utc.usu.edu/factsheets/CarexFSF/CIG/rhexia_anthers4_lg.jpghttp://utc.usu.edu/factsheets/CarexFSF/CIG/rhexia_anthers4_lg.jpg

49. Pollen grain begins growing from stigma toward ovary. • Discharges 2 sperm cells into female gametophyte. • 1 sperm fuses with egg nucleus to form diploid zygote. • Develops into embryo. • Embryo has rudimentary root; one (in monocots) or two seed leaves (in dicots), cotyledons.

50. http://biofinity.org/images/Pollen%20Grain%20Micrograph.jpg