Across
- 2. type of neurone that transmits information from the central nervous system to effectors
- 3. a reaction to something that has happened
- 7. type of neurone that transmits information from receptors to the central nervous system
- 9. an action that is performed without conscious thought as a response to a stimulus
- 13. type of system that detects and responds to changes of its surroundings
- 14. a substance used to stimulate immunity to a particular infectious disease or pathogen
- 16. growth or movement in plants in response to environmental stimuli
- 17. production of immunity by artificial means
- 18. organ which can produce a response to environmental stimuli
- 19. a detectable change in the physical or chemical structure of an organism's internal or external environment
- 20. an illness or sickness characterised by specific signs or symptoms
Down
- 1. cell that transmits electrical impulses around the body
- 4. type of gland that secretes hormones into the bloodstream
- 5. chemical messengers
- 6. able to be passed from one person, animal, or plant to another
- 8. organ which detects environmental stimuli
- 10. main organ of the central nervous system
- 11. maintenance of a constant internal environment
- 12. a plant hormone that regulates growth
- 15. lowest part of the brain that controls the body’s automatic processes