# Explain how cells are organised into tissues, organs and organ systems in a multicellular organism.

> WJEC GCSE Biology (Wales) — 1.1.1 Cell structure and organisation · Explain · 4 marks

## Mark scheme (4 marks)

1. A tissue is a group of cells with a similar structure working together to carry out a particular function
2. An organ is made up of different tissues working together to carry out a particular function
3. An organ system is a group of organs working together to carry out a particular function
4. A correct and relevant example given at any level of organisation (e.g. muscle tissue; heart/stomach as an organ; digestive/circulatory system as an organ system)

## Key terms

- [tissue](https://www.gradenine.co.uk/glossary/tissue)
- [organ](https://www.gradenine.co.uk/glossary/organ)
- [organ system](https://www.gradenine.co.uk/glossary/organ-system)
- [multicellular organism](https://www.gradenine.co.uk/glossary/multicellular-organism)

## 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)
- [Practice this with AI marking (free)](https://www.gradenine.co.uk/start)

---
Source: [GradeNine](https://www.gradenine.co.uk/q/explain-how-cells-are-organised-into-546366aa) · Published by Druglandscape Ltd.