# Explain why brothers and sisters from the same two parents can look different from each other.

> WJEC GCSE Biology (Wales) — 2.3.2 Inheritance · Explain · 4 marks

> Humans inherit characteristics from both of their parents. Although siblings share the same mother and father, they are not identical to each other (unless they are identical twins).

## Mark scheme (4 marks)

1. Each parent has two alleles for each gene / characteristic
2. Only one allele from each parent is passed on to the offspring (during reproduction)
3. Which allele is passed on is random / different combinations of alleles are possible
4. So each child receives a different combination of alleles, leading to different characteristics / phenotypes

## Related

- [Revision notes for WJEC GCSE Biology (Wales)](https://www.gradenine.co.uk/learn)
- [How to answer "Explain" questions](https://www.gradenine.co.uk/tools/command-word-cheatsheet)
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