# Describe the four levels of organisation in a multicellular organism, starting from the simplest level.

> AQA GCSE Biology (8461) — 4.2.1 Principles of organisation · Describe · 4 marks

## Mark scheme (4 marks)

1. Cell is the basic building block / simplest level of organisation
2. A tissue is a group of cells with a similar structure and function
3. Organs are aggregations of tissues performing specific functions
4. Organ systems are groups of organs that work together to form organisms

## Key terms

- [cell](https://www.gradenine.co.uk/glossary/cell)
- [organ](https://www.gradenine.co.uk/glossary/organ)

## Related

- [Revision notes for AQA GCSE Biology (8461)](https://www.gradenine.co.uk/learn)
- [How to answer "Describe" questions](https://www.gradenine.co.uk/tools/command-word-cheatsheet)
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Source: [GradeNine](https://www.gradenine.co.uk/q/describe-the-four-levels-of-organisation-ae13bb5a) · Published by Druglandscape Ltd.