Sexual Reproduction in Plants

1. Sexual Reproduction in Plants

2. Sexual Reproduction – Plants! Cycle that allows plants to reproduce sexually is the same as in animals. Seeds are the products of sexual reproduction in most plants. Seed – contains an embryo, a food supply, and a seed coat, which protects the seed from drying out.

3. Plants! Seed-producing plants can be divided into 2 groups: Angiosperms – enclosed seed Gymnosperms – naked seed

4. Angiosperms Flowering plants Seeds form inside the flower When mature, the seeds are enclosed in a shell, such as a pod or a case. Some have showy flowers – such as a lily. Others produce very tiny flowers – such as grasses.

5. Angiosperms Flowers contain the reproductive organs. The female reproductive organ is called the pistil. The male reproductive organ is called the stamen.

7. Pistil Includes: Stigma – sticky lip of the pistil that captures pollen grains Style – stalk that supports the stigma Ovary – swollen base containing ovules Ovules – sacs containing female gametes

8. Stamen Includes: Anther – where the pollen is produced and stored Pollen Grains – cases containing male gametes Filament – stalk the supports the anther

9. Pollination Pollination –seeds begin to develop when the pollen grains reach the stigma of the pistil. Self- Pollination - both male and female gametes come from the same flower Cross – Pollination - brings together gametes from different parent plants. The 2 most common helpers for cross-pollination are the wind and insects

10. Pollination Pollination is not enough to ensure fertilization. The pollen grains must grow a pollen tube – which will grow and reach the ovule inside the pistil.

11. Seed Matured When the sperm reaches the egg it creates a zygote. The zygote will undergo Mitosis and create a many celled embryo with a miniature leaf, root and stem, and a case that surrounds it and stores food. As the seed matures it forms a fruit – such as a pod or a case, around the seed.

12. Seed Dispersal This increases the likelihood that offspring will survive – as they will not be competing with the parent for water, soil, and sunlight. Animals, wind, and running water help with the dispersal of seeds. http://www.youtube.com/watch?v=sr4Khc7BUzA

13. Gymnosperms Gymnosperms produce their seeds inside cones – cones are the reproductive organs. Some species will produce female and male cones on separate tress – while others produce both cones on the same tree. http://www.youtube.com/watch?v=p0PctCgj66Q

14. Check your Understanding! Answer the following questions: Page 59 1, 4 Page 71 2a c, 3