# A cat breeder notices that some cats in a litter have short fur and some have long fur. Short fur is controlled by a dominant allele (F) and long fur is controlled by a recessive allele (f). Both parent cats have short fur. Explain why two short-furred parents can produce a long-furred kitten.

> OCR GCSE Biology A: Gateway Science (J247) — B5.1 Inheritance · Explain · 4 marks

> Short fur in cats is controlled by a dominant allele (F). Long fur is controlled by a recessive allele (f). A litter of kittens is born to two short-furred parents, yet one kitten has long fur.

## Mark scheme (4 marks)

1. Both parents must carry the recessive allele (f) for long fur / both parents are heterozygous (Ff)
2. The recessive allele (f) is only expressed when two copies are present / the long-furred kitten must have inherited one recessive allele from each parent
3. The long-furred kitten has the genotype ff
4. The short-furred parents show the dominant phenotype but their genotype means they can pass on the recessive allele / dominant allele masks the recessive allele in the parents

## Key terms

- [dominant](https://www.gradenine.co.uk/glossary/dominant)
- [recessive](https://www.gradenine.co.uk/glossary/recessive)
- [allele](https://www.gradenine.co.uk/glossary/allele)

## Related

- [Revision notes for OCR GCSE Biology A: Gateway Science (J247)](https://www.gradenine.co.uk/learn)
- [How to answer "Explain" questions](https://www.gradenine.co.uk/tools/command-word-cheatsheet)
- [Practice this with AI marking (free)](https://www.gradenine.co.uk/start)

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Source: [GradeNine](https://www.gradenine.co.uk/q/a-cat-breeder-notices-that-some-097ae0ad) · Published by Druglandscape Ltd.