Gymnosperm & Angiosperm
AP Biology 2004-2005
27 Gymnosperm: conifers . Characteristics 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 . reduced (microscopic) gametophyte . reduction of gametophyte protects delicate egg & embryo in protective sporophyte protected from drought & UV radiation AP Biology 2004-2005
28 Evolutionary trends in land plants . Reduction in gametophyte
gymnosperm bryophytes pteridophytes angiosperm
AP Biology 2004-2005
29 Early Gymnosperm: ginkgo
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30 Early Gymnosperm: cycads
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31 Gymnosperm: conifers
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32 Cones & naked seeds
AP Biology 2004-2005
33 Gymnosperm (Pine) life cycle female gametophyte in cone
meiosis meiosis
male gametophyte in pollen
sporophyte fertilization AP Binio loseedgy 2004-2005
34 sporangium & pollen
male male (pollen) cones
female
AP Bifoelomgyale cones pine embryo 2004-2005
35 Angiosperm: flowering plants . Characteristics vascular heterospory . male vs. female gametophytes flower . specialized structure for sexual reproduction seeds within fruit pollen life cycle dominated by sporophyte stage . trees & bushes you are familiar with are diploid . reduced (microscopic) gametophyte AP Biology 2004-2005
36 Angiosperm: flowering plants
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37 Co-evolution: flowers & pollinators
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38 Angiosperm: fruiting plants
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39 Angiosperm life cycle
AP Biology 2004-2005
40 Flower . Modified shoot with 4 rings of modified leaves
sepals
petals
stamens . male
carpals . female
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41 AP Biology 2004-2005
42 Angiosperm life cycle male gametophyte in pollen
fertilization
female gametophyte in ovary
sporophyte in seed
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43 AP Biology 2004-2005
44 Angiosperm . Flowering plants
flowers and fruit
monocots . 1 seed leaf . leaves with parallel
dicots . 2 seed leaves . leaves with net-like venation
AP Biology 2004-2005
45 Dicot . dicots
2 seed leaves
leaves with net-like venation
broad leaf plants
AP Biology 2004-2005
46 Monocot . monocots
1 seed leaf
leaves with parallel
grasses, grains, bulbs
AP Biology 2004-2005
47 Evolutionary trends . Vascular tissue tubes for transport non-vascular . bryophytes - mosses vascular . pteridophytes - ferns . gymnosperm - conifers . angiosperm - flowering plants . Evolutionary advantage? adaptation to dry terrestrial conditions allows increased size (think trees!)
AP Biology 2004-2005
48 Evolutionary trends . Sperm dissemination flagellate (swimming) sperm . bryophytes - mosses . pteridophytes - ferns wind-blown or animal-carried pollen . gymnosperm - conifers . angiosperm - flowering plants . Evolutionary advantage? adaptation to dry terrestrial conditions . eliminated water requirement for fertilization
AP Biology 2004-2005
49 Evolutionary trends . Seeds seedless plants . bryophytes - mosses . pteridophytes - ferns seed plants . gymnosperm - conifers . angiosperm - flowering plants . Evolutionary advantage? adaptation for reproduction in diverse terrestrial environments . resistant, dispersal stage
AP Biology 2004-2005
50 Evolutionary trends . Reduction of gametophyte gametophyte dominant . bryophytes - mosses sporophyte dominant, free living gametophyte . pteridophytes - ferns sporophyte dominant, reduced gametophyte . gymnosperm - conifers . angiosperm - flowering plants . Evolutionary advantage? adaptation for reproduction in diverse terrestrial environments . reduction of gametophyte protects delicate egg & embryo in protective sporophyte . protected from drought & UV radiation AP Biology 2004-2005
51 Evolutionary trends . The 4 groups represent 4 great episodes in the evolution of land plants
evolution of land plants from ancestral . green algae → mosses
evolution of vascular plants . ferns
evolution of seeds . gymnosperm
evolution of flowers . angiosperm
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