Science rev

2. an organ or cell that acts in response to a stimulus
4. the smallest particle of a chemical element that can exist
5. what makes up CNS
7. A thingy. Theory
8. the square thingy
10. a process in living organisms involving the production of energy, typically with the intake of oxygen and the release of carbon dioxide from the oxidation of complex organic substances.
14. a thing or event that evokes a specific functional reaction in an organ or tissue
15. central nervous systems

1. the process by which green plants and some other organisms use sunlight to synthesize nutrients from carbon dioxide and water
3. where animals live
6. The hormone that helps regulate our blood sugar level
9. a flat, coloured, ring-shaped membrane behind the cornea of the eye,
11. non living things
12. the stimuli for the sense of hearing
13. living things