1. Reproduction in Flowering Plants
Objective:
Describe the reproductive organs of the plant
Explain the process of sexual reproduction in angiosperms
Describe the structure and function and structure of seeds
Homework: Learn about and describe different methods of seed dispersal

2. Quiz
1. Why are the palisade and the spongy mesophyll called the ‘working layers’ of the leaf?
What is cambium and what does it do?
How does the arrangement of the stomata leading into the spongy mesophyll (filled with air spaces) ensure chlorophyll containing cells have a constant supply of carbon dioxide for photosynthesis?
On board

3. 9Ad
Parts of a flower 3

4. Sexual Reproduction in Angiosperms
Plants reproduce sexually
The products of this sexual reproduction are seeds.
These seeds are contained inside an ovary. Which develops into a fruit.

5. Reproductive Parts Male reproductive organs (stamen):
Anther: produces pollen grains
Filament: supports anther above female reproductive organs
Female reproductive organs (carpel):
Stigma: sticky landing site for pollen grains
Style: tube that leads down to ovary
Ovary: contains ovules that develop into seeds

6. Reproductive Mechanisms
9Ad
Reproductive Mechanisms
Pollen (male gamete) from one plant lands
on the stigma of another plant.
This is called pollination.
pollen
stigma 6

7. Methods of Pollination
Natural Reproduction
Pollination in angiosperms can happen by wind or animals.
Animals can transfer pollen (bees) from one plant to the other.
They are called pollinators
Pollen can be blown from one plant to another.
Wind dispersal

8. Reproduction

10. Selective breeding in plants
9Ad
Selective breeding in plants
texture
size
Selective breeding and cross-breeding are carried out on plants to produce flowers and crops with desirable characteristics…
taste
colour 10

11. 9A Plant-breeding techniques
Anne the plant breeder chooses two parent plants with useful characteristics.
One plant will be the female parent. Anne removes the anthers and covers the flower with a bag. Why?
female parent
The other plant is the male parent. Its anthers develop as normal.
Anne collects its pollen and brushes it onto the female plant.
collected pollen
anthers removed
She puts the bag over the flower again. Later she collects the seeds and grows them to produce the new plant.

12. From Pollen to Ovary The pollen grain grows a pollen tube
9Ad
From Pollen to Ovary
The pollen grain grows a pollen tube
towards the ovary, which contains the ovule and egg cell (female gamete).
pollen tube
ovary containing ovule 12

13. 9Ad
Fertilization
Fertilisation takes place when the ‘sperm’ nucleus from the pollen grain enters the egg cell. The resulting zygote eventually turns into a seed.
pollen tube with pollen grain nucleus
ovule
Embryo grows inside the ovule.
egg cell 13

14. Compare
With your neighbour, discuss how the reproductive system in plants is similar to the reproductive system in humans.

15. Quiz Name three different methods of seed dispersal.
Chose one method and explain how it effectively disperses seeds away from plant.
What are the male parts of the plant called?
What is it called when pollen from one plant lands on the stigma of another plant.

16. Comparing Plant and Human Reproductive Systems
Male and Female organs
Male Gamete is pollen
Female Gamete is egg produced in ovule
Pollen nuclei fuses with egg nuclei (fertiliation)
Diploid zygote
Zygote grows into embryo
Embryo grows inside protective seed coat
Cotyledons provide nourishment
Male or Female organs
Male Gamete is sperm
Female Gamete is egg produced in ovary
Sperm nuclei fuses with egg nuclei (fertilization)
Diploid zygote
Zygote grows into embryo
Embryo grows inside protective womb
Placenta provides nourishment

17. Zygote to Embryo
The zygote will grow through the process of mitosis to form an embryo (The ovule is now called a seed and is covered by a protective seed coat.)
seed
seed coat
food supply
(cotyledon)
embryo

18. Fruit Formation Some plants produce fruit containing seeds.
Fruit: Mature ovary
Tissue surrounding the embryo develops into fruit.
When the fruit is fully developed it drops off the plant, or is carried away by an animal.
When fruit decomposes it releases the seed and germination can occur.

19. Germination A seed requires moisture (water) to germinate.
The as the embryo grows, the root and shoot break through the seed coat.
Nutrients stored in the cotyledon provide nourishment and support early development

20. Life cycle of an angiosperm

22. Plenary.. What is the function of the flower? What is a seed?
What basic condition is required for a seed to germinate?
Describe two methods of pollination.