Reproduction in Plants Flowering

Reproduction in Plants Flowering Label a diagram of a dicotyledonous flower (monoecious) Petal 1. …………………………………… Anther 2. …………………………………… Filament 3. …………………………………… Stamen 4. …………………………………… Stigma 5. …………………………………… Style 6. …………………………………… Ovule 7. …………………………………… Pistil 8. …………………………………… Sepal 9. …………………………………… Distinguish between pollination, fertilisation and seed dispersal Transfer of pollen from the anther to the stigma (usually between different plants) Pollination: …………………………………………………………………………………………………………………………………….. Fusion of male gamete nuclei (in pollen) with female gamete nuclei (in ovule) Fertilisation: …………………………………………………………………………………………………………………………………… Fertilised ovule (seed) moves away from parent plant to reduce competition Seed Dispersal: ……………………………………………………………………………………………………………………………….. Outline the role of pollinators in plant reproduction Most flowering plants will use mutualistic relationships with pollinators to reproduce ………………………………………………………………………………………………………………………………………………….......... The plant gains a mechanism of pollen transfer, while the animal gains source of nutrition (e.g. nectar) ………………………………………………………………………………………………………………………………………………….......... ………………………………………………………………………………………………………………………………………………….......... Define photoperiodism The response of a plant to the length of day or night ………………………………………………………………………………………………………………………………………………….......... ………………………………………………………………………………………………………………………………………………….......... Explain, with the aid of the diagram, how flowering occurs in short day plants and long day plants Phytochrome exists in two forms: an inactive form (Pr) is predominant at night, while an active form (Pfr) ………………………………………………………………………………………………………………………………………………….......... is predominant during day (flowering is triggered by the active form and requires a critical night length) ………………………………………………………………………………………………………………………………………………….......... In long day plants, Pfr activates flowering so flowering is induced when night is short (⬆ Pfr) ………………………………………………………………………………………………………………………………………………….......... In short day plants, Pfr inhibits flowering so flowering is induced when night is long (⬇ Pfr) ………………………………………………………………………………………………………………………………………………….......... ………………………………………………………………………………………………………………………………………………….......... Describe one strategy horticulturalists can use to promote flowering of short day plants out of season Horticulturalists can manipulate flowering by controlling the exposure of light ………………………………………………………………………………………………………………………………………………….......... Short day plants can be induced to flower by covering with a black cloth for ~12 hrs a day ………………………………………………………………………………………………………………………………………………….......... Germination Label the diagram of a seed Epicotyl (embryonic shoot) 1. …………………………………………………………………………………... Radicle (embryonic root) 2. …………………………………………………………………………………... Micropyle (pore for water uptake) 3. …………………………………………………………………………………... Cotyledon (food store / forms embryonic leaf) 4. …………………………………………………………………………………... Testa (seed coat) 5. …………………………………………………………………………………... Identify factors that contribute to the germination of a plant Germinating seeds require oxygen (for ATP via aerobic respiration), water (to metabolically activate cells), ………………………………………………………………………………………………………………………………………………….......... temperature (for optimal enzyme activity) and pH (suitable soil conditions for enzymes) ………………………………………………………………………………………………………………………………………………….......... In addition, particular species may require specialised conditions, such as fire, freezing, washing, digestion …………………………………………………………………………………………………………………………………………………..........