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How to avoid having sex with your (plant) self
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 I> | How many ways can you think of to avoid sex with self if you're a plant?
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 A. | Minimum: at least don't have sex with your own floral self
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 1. | Pollen created by anther = leaf-derived male generating/dispersing structure
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 2. | Female landing surface = stigma, tubular route to the ovum = style
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 3. | Pollen delivered by wind, water or animal agency. It is a haploid organism that will grow its way to an ovule
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 4. | pollen germinates on a plant this require active moistening of the pollen grain by the stigma
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 5. | Some fancy stuff occurs where 1 pollen nucleus fuses with 1 ovum nucleus to yield 2N embryo; a second pollen nucleus fuses with 2 ovum nuclei to yield 3N endosperm (= food for baby)
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 II> | Some answers (don't go here until you've thought it through yourself and have as many answers as you can come up with)
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 A. | 'self incompatibility' (where studied, often 1 locus, many alleles; if alleles match, just say no)
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 1. | if pollen and stigma 'recognize' each other (at the molecular level), stigma fails to hydrate pollen (normally, pollen germination is triggered by hydration performed by stigma), Brassica
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 2. | Pollen tube's continued growth may be physically blocked by within style Grasses
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 3. | Pollen may be induced to 'prematurely ejaculate'--normally the pollen tube 'bursts' when it reaches the ovule; in some incompatibility systems, this is apparently induced prior to reaching ovule
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 a. | b and/or c found in legumes, poppies, Solanaceae (potatoes/tomatoes), lilies
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 4. | Abortion of fertilized ovules (cocoa)
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 C. | Separate male and female plants (Ginkgo)
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 D. | Separate maturation time of male and female parts within a flower
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 E. | Separate physical location of male and female parts (dusting/receiving pollen from diff't parts of insect)
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 F. | Male and female parts on different points in 'travel paths'; conceptually they collect pollen on ingress; deliver on egress (bug small compared to flower) (some orchids, incl. Coryanthes)
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