Year 7 Biology: Fertilisation and Seed Formation

Introduction to Fertilisation

Fertilisation is the process that happens when a male and female reproductive cell join together. This is a very important step in the life cycle of plants.

What are Reproductive Cells?

• Pollen: This is the male reproductive cell found in flowers.
• Ovule: This is the female reproductive cell found in the ovary of the flower.

How Does Fertilisation Happen?

1. Pollination: Pollen from the male part of a flower (the anther) is transferred to the female part (the stigma).
2. Fertilisation: Once the pollen reaches the stigma, it grows a tube down into the ovary where the ovule is located. The sperm cell from the pollen travels down this tube to meet the ovule.
3. Joining Together: When the sperm cell meets the ovule, they join together. This is called fertilisation.

Example of Fertilisation

Think of a flower like a little factory. The pollen is like a worker coming from one factory (the male part) to join with another factory (the female part) to create a new product, which in this case is a seed!

Seed Formation

After fertilisation, the fertilised ovule develops into a seed.

Steps in Seed Formation

1. Development: The fertilised ovule begins to grow. This is the start of a new seed.
2. Seed Coat: The outer layer of the ovule changes and hardens to form a protective coat around the seed.
3. Stored Food: Inside the seed, there is stored food that will help the new plant grow when it starts to sprout.
4. Germination: When the conditions are right (like warmth and moisture), the seed will sprout and grow into a new plant.

Visual Representation

(This is an example image link; please replace with an actual image.)

Key Rules to Remember

• Pollination is essential for fertilisation.
• Fertilisation leads to seed formation.
• Each seed has a protective coat and food inside it.

Tips and Tricks

• Use diagrams to visualise the parts of a flower and the process of fertilisation.
• Remember that some plants rely on wind or insects for pollination.
• Think of seeds as baby plants waiting for the right conditions to grow.

Questions

Easy Level Questions

1. What is the male reproductive cell in plants?
2. What is the female reproductive cell in plants?
3. What do we call the process of pollen reaching the stigma?
4. What does the pollen grain grow into after it lands on the stigma?
5. What does fertilisation create?
6. What is formed from a fertilised ovule?
7. What part of the flower holds the ovule?
8. What is inside a seed that helps it grow?
9. What do we call the outer layer of a seed?
10. What do seeds need to start growing?
11. What is pollination?
12. Where does fertilisation take place?
13. What is a flower’s anther?
14. Why is fertilisation important for plants?
15. How does a pollen grain reach the ovule?
16. What happens during germination?
17. Name one way pollen can be transferred.
18. What does a seed turn into when it germinates?
19. What do you call the process of a seed sprouting?
20. What are the conditions needed for germination?

Medium Level Questions

1. Describe the steps of fertilisation in plants.
2. How does a pollen tube help in fertilisation?
3. What role do insects play in pollination?
4. Explain the difference between male and female parts of a flower.
5. Why do seeds have a protective coat?
6. What happens to the ovule once it has been fertilised?
7. How long can seeds remain dormant before germinating?
8. What environmental factors affect germination?
9. Describe the structure of a seed.
10. How does the stored food in a seed help the plant?
11. What happens if a seed does not receive enough moisture?
12. How do flowers attract pollinators?
13. What is the relationship between pollination and fertilisation?
14. How can you tell if a seed is healthy?
15. What are the signs that a seed is germinating?
16. Why do some plants produce more pollen than others?
17. Describe a method for planting seeds.
18. What is cross-pollination?
19. How do farmers use knowledge of fertilisation in agriculture?
20. What challenges do seeds face in nature?

Hard Level Questions

1. Describe the genetic implications of fertilisation in plants.
2. What are the advantages of sexual reproduction in plants?
3. How does fertilisation ensure diversity in plant populations?
4. Explain how environmental changes can affect the fertilisation process.
5. Discuss the role of pollinators in ecosystems.
6. What adaptations do plants have for fertilisation?
7. Explore the difference between self-pollination and cross-pollination.
8. How can human activity impact the fertilisation of plants?
9. What are some common methods of seed dispersal?
10. Explain the process of hybridisation in plants.
11. How can seeds remain viable for long periods?
12. Discuss the role of temperature in seed germination.
13. What are the implications of hybrid plants for biodiversity?
14. Explain how plant hormones affect seed development.
15. What factors can prevent fertilisation in flowers?
16. Compare and contrast the life cycles of flowering plants and non-flowering plants.
17. How do different species of plants ensure successful fertilisation?
18. Investigate the importance of genetic variation in agriculture.
19. How can we use technology to improve seed formation and growth?
20. Discuss how climate change might affect plant fertilisation and seed formation.

Answers

Easy Level Answers

1. Pollen
2. Ovule
3. Pollination
4. A pollen tube
5. A seed
6. A seed
7. The ovary
8. Food
9. Seed coat
10. Warmth and moisture
11. Pollination
12. In the ovary
13. The male part of the flower
14. To produce new plants
15. By insects or wind
16. It starts to grow
17. By attracting insects
18. A new plant
19. Germination
20. Warmth and moisture

Medium Level Answers

1. Pollination, pollen tube growth, sperm cell meets ovule.
2. It helps deliver the sperm cell to the ovule.
3. They help transfer pollen from one flower to another.
4. The male parts produce pollen; the female parts contain ovules.
5. To protect the seed from damage.
6. It develops into a seed.
7. Some seeds can last for years.
8. Light, water, and temperature.
9. It has a seed coat, stored food, and an embryo.
10. It provides energy for the young plant.
11. The seed may not germinate.
12. By using bright colours and scents.
13. Pollination allows for fertilisation to occur.
14. Healthy seeds will sprout quickly.
15. The seed will not grow.
16. To maximize reproduction chances.
17. Plant seeds in soil and water them.
18. When pollen from one plant fertilises another.
19. They select seeds for better traits.
20. Predators or environmental changes.

Hard Level Answers

1. It mixes genes from both parents.
2. It encourages variation and adaptation.
3. It helps plants survive in changing environments.
4. Changes can affect pollen production or timing.
5. They help plants reproduce and maintain populations.
6. Some flowers have shapes that attract specific pollinators.
7. Self-pollination occurs within the same flower; cross-pollination involves different flowers.
8. Pollution and habitat destruction can reduce pollinator numbers.
9. Wind, animals, and water can disperse seeds.
10. They can remain dormant until conditions are right.
11. Some seeds can survive for decades.
12. Higher temperatures can speed up germination.
13. Hybrids can be more robust but may reduce genetic diversity.
14. They influence growth and development of seeds.
15. Poor weather or lack of pollinators.
16. Flowering plants have complex reproductive structures, while non-flowering plants do not.
17. They may have specific flowering times or shapes.
18. It helps create stronger plants and better yields.
19. Technologies like genetic engineering can help.
20. It may alter growing seasons and pollinator activity.