Across
- 5. is made up of tissues to perform a specific function
- 6. a natural substance that is produced in the body and that influences the way the body grows or develops
- 8. a loop system in which the system responds to positive feedback or negative feedback
- 11. the narrow, winding, upper part of the intestine where digestion is completed and nutrients are absorbed by the blood
- 12. a nerve cell
- 13. the structural and functional unit of the kidney
- 14. the process of taking in substances
- 15. a sac in the lungs where the exchange of oxygen and carbon dioxide takes place
- 17. absorbs nutrients in the food
- 20. a detectable change in the internal or external environment.
Down
- 1. is a molecule that is acted upon by an enzyme
- 2. a large protein which speeds up chemical reactions
- 3. a reaction to stimulus
- 4. the process of breaking down food
- 7. receives chemical signals from outside the cell
- 9. the ability of an organism or cell to maintain internal equilibrium
- 10. carries a signal from one nerve cell to another
- 16. a hormone produced in the pancreas that regulates the amount of glucose in the blood
- 18. organs whose function is to remove carbon dioxide from the blood and provide it with oxygen
- 19. is made up cells that work together to perform a specific function