# "Explain" questions — WJEC GCSE Biology (Wales)

> 102 questions · biology

## How to answer

WHAT + WHY. Every point paired with a because. Structure: X happens because Y. This causes Z because … Assessment Objective: AO2. Every "explain" answer on this spec is marked against exactly this pattern.

## Sample questions

1. [Explain why a person who has recovered from chickenpox is unlikely to become ill from the same disease again.](https://www.gradenine.co.uk/q/explain-why-a-person-who-has-080c18cd)
2. [Explain why the energy requirements of two people of the same age and body mass may be different.](https://www.gradenine.co.uk/q/explain-why-the-energy-requirements-of-098ddfbc)
3. [Explain why a habitat with a large number of different species is considered to have high biodiversity.](https://www.gradenine.co.uk/q/explain-why-a-habitat-with-a-09c01890)
4. [Explain why decomposers are essential for returning nutrients to the soil, and describe what would happen to plant growt…](https://www.gradenine.co.uk/q/explain-why-decomposers-are-essential-for-104e2fd4)
5. [A scientist investigates two samples of muscle tissue. Sample A is taken from a sprinter immediately after a 100 m race.…](https://www.gradenine.co.uk/q/a-scientist-investigates-two-samples-of-113c1544)
6. [Explain how the nitrogen found in a dead animal's body is eventually made available to plants growing in the soil.](https://www.gradenine.co.uk/q/explain-how-the-nitrogen-found-in-13104f58)
7. [Explain why reflex actions are important for survival.](https://www.gradenine.co.uk/q/explain-why-reflex-actions-are-important-147e7352)
8. [Explain why the left ventricle has a thicker muscular wall than the right ventricle.](https://www.gradenine.co.uk/q/explain-why-the-left-ventricle-has-15643cd7)

## Related

- [WJEC GCSE Biology (Wales) revision notes](https://www.gradenine.co.uk/learn/wjec-gcse-biology-wales)
- [WJEC GCSE Biology (Wales) past papers](https://www.gradenine.co.uk/past-papers/wjec-gcse-biology-wales)
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