Topic 9: Reproduction in Angiospermophytes 9.3

1. Topic 9: Reproduction in Angiospermophytes 9.3

2. Draw and label a diagram showing the structure of a dicotyledonous animal-pollinated flower • Limit the diagram to: sepals, petals, anther, filament, stigma, style and ovary

5. Distinguish between pollination, fertilization, and dispersal

6. Draw and label a diagram showing the external and internal structure of a named dicotyledonous seed • Testa (seed coat), hypocotyl (embryonic shoot), radicle (embryonic root), cotyledons (seed leaves) Pisum sativum (common pea)

7. Explain the conditions needed for seed germination • Water = rehydration of dry tissue • Oxygen = aerobic cell respiration • Suitable temperatures for enzymatic activity

8. Outline the metabolic events during the germination of a starchy seed • Stage 1 – water absorption • Stage 2 – gibberelin (growth hormone) produced by cotyledons = growth hormone • Stage 3 – gibberelin stimulates amylase production = chem. breakdown of starch into maltose in food stores of the seed • Stage 4 – maltose transported to radicle and plumulue • Stage 5 – maltose converted to glucose = E or synthesis of materials for growth (e.g. cellulose) • Stage 6 – cessation once leaves and sun connect

9. Explain how flowering is controlled in long-day and short-day plants, including the role of phytochrome • Key points: • Phytochrome is a light absorbing pigment • Phytochrome exists in two interchangeable forms: phytochrome red (Pr) and far-red (Pfr). • Only Pfr is biologically active • ****Pfr is a promoter of flowering in long-day plants and it inhibits flowering in short-day plants

11. Draw a similar presentation for Long-day (short-night) plants