Sexual Reproduction in Plants

1. Sexual Reproduction in Plants Section 2.3 (p.60 to p.71)

2. Plant Seeds are a Total Package. • A plant seed is a complete package containing an embryo, food supply and a protective coating that stops the seed form drying out, called the seed coat. • There are 2 types of plants that produce seeds: • Angiosperms • Gymnosperms

3. Sexual Reproduction Organs in Angiosperms • Female reproductive organ is called the pistil. • Male reproductive organ is called the stamen.

5. Pollination & Fertilization in Angiosperms • Pollination occurs when pollen grains containing male gametes from anthers reach stigma of pistil where female gametes are found.

6. Pollination & Fertilization in Angiosperms Continued… • In self-pollination both male & female gametes come from the same plant. • In cross-pollination male & female gametes come from different plants. • In this process male gametes (known as pollen) are carried to other plants by the wind and/or insects.

7. Pollination & Fertilization in Angiosperms Continued… • After pollination is achieved the pollen must grow an extension called a pollen tube so that its gametes can reach the female gametes.

8. ------------Pollen Tube ------------Pollen Tube Self-Pollination Cross-Pollination

10. Seed Development in Angiosperms • Once the male & female gametes come together a zygote is formed. • The zygote goes through many mitotic divisions to form a multi-celled embryo with a miniature leaf, root and stem. • Embryo is surrounded by a food sac and seed coat.

12. Ovary grows to form fruit that contain seeds. Seeds are Incased in Ovary

14. How do Seed Disperse? • The fruit produced by angiosperms is transported away from the parent plant by animals, the wind and water. • Wherever the fruit ends up a new plant can begin to form. • New plant will only form if the conditions are right (proper soil, temperature, moisture & sunlight).

15. Germination • Germination is the process in which a seed begins to grow. • A seed can remain dormant (inactive) for years and only grow when the conditions become favorable. • Once a mature plant grows from the seed it will reproduce sexually to produce the next generation of plants.

16. Gymnosperms • The life cycle of a gymnosperm is very similar to that of a angiosperm; however, their seeds arenot contained in a fruit.

17. Sexual Reproduction in Plants Without Seeds • Plants such as moss reproduce without seeds. • These plants reproduce through spores. A spore can develop into a new plant without fertilization.