Lecture21_PlantsII - Charales: diploid stage is Mosses:...

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Plants II II. Adaptations to land, continued E. Seeds 1. Mosses, horsetails, ferns: eggs develop in • advantages: • disadvantages: 2. What is a seed? • embryo + food supply surrounded by • advantages = • disadvantage = III. Life cycles and reproduction How do life cycles vary among plants? Recall protist life cycles Alternation of generations: presence of multicellular diploid and multicellular haploid individuals Sporophyte: A multicellular, diploid individual that produces haploid spores by meiosis; these spores germinate and divide by mitosis to form a haploid gametophyte Spore: a single cell produced by mitosis or meiosis that is capable of developing into an adult organism (without fusing with another cell) Gametophyte: A haploid, multicellular individual that produces gametes by mitosis; these gametes fuse to form a diploid cell (a zygote) that develops into a sporophyte Zygote: Cell (usually diploid) formed by fusion of gametes
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Unformatted text preview: Charales: diploid stage is Mosses: gametophyte Ferns: sporophyte Flowering plant: gametophytes B. Pollination 1. Correlations between flower structure and pollinator--hummingbird-pollinated--carrion fly pollinated--bee flowers:--wind pollinated flowers 2. What hypothesis are we invoking in making these correlations? Natural selection has favored the evolution of flowers that are Routinely observe that hand-pollination results in higher seed production than natural pollination What does this observation mean? Conclude: Selection on flower traits is strong, because 3. How would you test the hypothesis that the presence of putrescine is an adaptation that increases pollination by carrion flies? Experimental test: Need to alter traits experimentally, and show difference in pollinator attraction Null hypothesis: Experimental set-up: Prediction of hypothesis to be tested: Prediction of null hypothesis:...
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This note was uploaded on 04/10/2008 for the course BIOL 180 taught by Professor Freeman during the Fall '07 term at University of Washington.

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Lecture21_PlantsII - Charales: diploid stage is Mosses:...

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