B8: Reproduction in Plants

1. B8: Reproduction in Plants

2. Identify and draw the parts of an insect- pollinated flower 1 8 Stamen 9 2 7 6 3 5 4

3. Insect-pollinated flower parts

4. Identify and draw the parts of a wind-pollinated flower Sepal 1 Stigma 5 Anther 2 Stamen 4 Ovary 6 Filament 3

5. Differences between insect- and wind-pollinated flowers

6. Pollination • The transfer of pollen grains from the anther to a stigma of a plant of the same species • Insects and wind are 2 agents of pollination • Birds and bats and some mammals are others • When the anther is ripe, it will split, releasing the pollen • Insect-pollinated flowers provide an incentive for bees etc to visit the flower • The bee feeds on the nectar stored at the base of the flower, and gets coated in pollen from the anther • When the bee visits anther flower for more nectar it will brush the second stigma with pollen – pollination occurs Pollination in action pollination

7. Fertilisation • Once the pollen lands on the stigma, the grains start to grown down the style towards the ovary • The nucleus of the male gamete fuses with the egg cell nucleus in the ovule – fertilisation has occurred. • The zygote divides and grows into the embryo. • The ovule becomes the seed • The ovary is the fruit with the seeds inside Seed production

8. Germination • The growth of the embryo, forming a radicle (small root) • Water, oxygen and a suitably warm temperature are needed for germination • water swells the seed, breaking the seed coat and allowing the cells to develop vacuoles and swell • swelling of the seeds causes the radicle to grow • water allows the embryo to access the food stores in the seed • Oxygen is required for respiration to provide energy • the warmer temperature is needed for the enzymes to work efficiently Seed growth