11. Sex Encount Floral read later

11. Sex Encount Floral read later - SEXUAL ENCOUNTERS OF A...

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SEXUAL ENCOUNTERS OF A FLORAL KIND (Video) I. Flowering plant biology- A. Seed pod explodes- initiating plant life B. Flowers- Purpose: Sex (Time-lapse of anthesis events) C. Most flowers have male & female sexes 1. Sex parts- Female: Stigmas (receptive) Male: Anthers with pollen 2. Selfing easy with both sexes in one flower, but cross-pollination needed for genetic variation and adaptation 3. How do plants achieve cross-pollination when literally rooted? II. Hammer-head orchid & thynnid wasps in Australia- A. Thynnid wasp female (wingless) emerges from soil 1. Will return to soil to paralyze & lay eggs in beetle grubs 2. Climbs plant, opens mandibles to release "perfume" [Pheromone] attractive to winged male 3. Males emerge a couple of weeks before female [Protandrous] 4. Male picks up female- carries her to flower where he feeds 5. Mating starts while in flight 6. Female obtains food and sperm through male abdomen B. Orchid exploits wasp mating behavior 1. Flower shape and odor mimic female wasp 2. Male wasp attracted to dummy female, picks up pollen sacs 3. Male wasp must visit 2nd orchid for cross-pollination to occur 4. After female wasps emerge, male wasps no longer fooled by orchids [Timing is critical for orchid] [Narrow window between male and female wasp emergences] III. Adaptations of flowers for insects & other animal pollinators- A. Grasses- pollen carried by wind [Anemophily] (Also many trees) 1. Wasteful of pollen. Why not use insects as "go-betweens?"
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This note was uploaded on 12/07/2009 for the course ECON 19993 taught by Professor Helms during the Spring '09 term at UC Davis.

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11. Sex Encount Floral read later - SEXUAL ENCOUNTERS OF A...

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