Body Systems

1. A group of similar cells working together to perform a function.
3. Joins two bones together.
5. Joins a muscle to a bone.
7. A pair of muscles that work together to control movement at a joint – as one muscle contracts, the other relaxes.
9. An organism made up of many cells
12. The transfer of gases between an organism and its environment.
14. Breathing in, to take in oxygen.
15. A chemical reaction where food and oxygen are converted into energy, water, and carbon dioxide.
16. A part of the skeleton where two bones join together.
18. A group of organs working together to perform a function.
20. A tissue that forms a hard structure, used to protect organs and for movement.

2. All the bones in an organism.
3. The organ in which gas exchange takes place.
4. Breathing out, to remove carbon dioxide.
6. The strong, smooth tissue that covers the end of bones to prevent them rubbing together.
8. A group of tissues working together to perform a function.
10. The organs involved in gas exchange.
11. The sheet of muscle used in breathing.
13. The unit of force, symbol N.
15. The bones that protect the lungs.
17. The change of state from gas to liquid.
19. A structure inside the lungs where gas exchange takes place with the blood.