# The eye and the ear are both sense organs that detect stimuli and send nerve impulses to the brain. Explain how the eye detects light and how the ear detects sound, including the roles of the receptor cells in each organ.

> Edexcel A-Level Biology A: Salters-Nuffield (9BN0) — 4.4 Vision and hearing · Explain · 5 marks

> Humans rely on two key sense organs — the eye and the ear — to gather information about their environment. Both organs contain specialised receptor cells that convert different types of stimuli into electrical nerve impulses.

## Mark scheme (5 marks)

1. The eye contains light receptor cells (rod cells and/or cone cells) located in the retina
2. Light entering the eye is focused onto the retina, stimulating the receptor cells to generate nerve impulses
3. Nerve impulses from the retina travel along the optic nerve to the brain
4. The ear contains hair cells (in the cochlea) that detect sound vibrations
5. Nerve impulses from the hair cells travel along the auditory nerve to the brain

## Key terms

- [receptor cells](https://www.gradenine.co.uk/glossary/receptor-cells)
- [nerve impulses](https://www.gradenine.co.uk/glossary/nerve-impulses)

## Related

- [Revision notes for Edexcel A-Level Biology A: Salters-Nuffield (9BN0)](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/the-eye-and-the-ear-are-94f31a12) · Published by Druglandscape Ltd.