Reproduction and Species Survival

Name:

Date:

Part 1: Understand the Science

Learning intentions: I can describe the form and function of reproductive cells and organs in animals and plants. I can compare sexual and asexual reproduction and explain how each can help a species survive.

Key information: Reproductive cells are called gametes. In animals, sperm and eggs are gametes. In flowering plants, pollen carries the male gametes and the ovule contains the female gamete. Fertilisation occurs when two gametes join to form a zygote. Sexual reproduction involves genetic material from two parents and usually produces variation in offspring. Asexual reproduction involves one parent and produces offspring that are genetically very similar to the parent. Examples include binary fission, budding and vegetative reproduction in plants. In a flower, the stamen produces pollen and the carpel contains the stigma, style, ovary and ovules. Variation can help some individuals survive environmental change, disease or predators.

1. Which statement best describes sexual reproduction?

It uses one parent and produces identical offspring.

It involves the joining of gametes and can produce variation.

It occurs only in plants.

It does not involve reproductive cells.

2. Match each term to its meaning.

A. Gamete

B. Fertilisation

C. Pollen

D. Variation

1. Differences between individuals of the same species

2. A reproductive cell

3. Male reproductive material produced by a flower

4. Joining of male and female gametes

3. Flower diagram task: Draw and label a simple flowering plant. Include the stamen, anther, filament, stigma, style, ovary and ovule. Add one sentence explaining the function of either the anther or the ovary.

4. Reproductive process diagram: Draw arrows to show the sequence from pollen production to seed formation. Label these stages: pollen, pollination, fertilisation, zygote and seed.

Part 2: Apply and Explain

5. Complete the comparison.

Sexual reproduction: Number of parents: ________ Genetic similarity of offspring: ____________________ Main advantage: ______________________________

Asexual reproduction: Number of parents: ________ Genetic similarity of offspring: ____________________ Main advantage: ______________________________

6. Describe the form and function of reproductive cells in one animal and one plant.

Animal example: __________________________________________________________________________

Plant example: ____________________________________________________________________________

7. Explain why variation produced by sexual reproduction may help a species survive a new disease or environmental change.

8. Application scenario: A group of plants lives in a stable grassland. A new insect disease arrives, and only a few plants show resistance. Recommend whether sexual or asexual reproduction would be more useful for the population now. Justify your recommendation using variation and survival.

9. Exit ticket: Complete both statements.

One difference between sexual and asexual reproduction is ____________________________________________

One way reproduction supports species survival is _________________________________________________

Answer Key and Suggested Marking Guidance

1. It involves the joining of gametes and can produce variation.

2. A–2, B–4, C–3, D–1.

3. Award labels for stamen, anther, filament, stigma, style, ovary and ovule. Accept accurate functions such as: the anther produces pollen; the ovary contains ovules; the stigma receives pollen.

4. Accept a logical sequence: pollen production → pollination → fertilisation → zygote formation → seed formation. Labels should be scientifically accurate.

5. Sexual: two parents; offspring are genetically varied; variation may improve survival in changing conditions. Asexual: one parent; offspring are genetically very similar or identical; rapid reproduction without needing a mate.

6. Responses should identify a reproductive cell and its function. Examples: an animal sperm is small and can move towards an egg; an animal egg is larger and contains stored nutrients; pollen carries male gametes; an ovule contains the female gamete.

7. Strong responses explain that variation means some individuals may have features that help them resist the disease or cope with the change. These individuals are more likely to survive and reproduce.

8. Recommended answer: sexual reproduction, because it increases variation and may produce more disease-resistant offspring. Accept a well-justified alternative if the reasoning is scientifically sound.

9. Accept accurate comparisons and explanations linking reproduction to producing new individuals, replacing populations and continuing the species.

Suggested marking: Questions 1–2: 1 mark each. Questions 3–4: 3 marks each for accurate labels, sequence and functions. Questions 5–6: 2 marks each. Questions 7–8: 3 marks each for accurate biological ideas, use of evidence and clear justification. Question 9: 2 marks. Total: 20 marks.