Across
- 2. daily food intake that contains all the different types of nutrient, and the right amount of energy
- 3. gradual increase of a substance in an organism; it happens when the substance cannot be broken down inside the body cells
- 5. a muscle that is attached to the shoulder blade and the radius bone; when it contracts, it makes the arm bend at the elbow
- 6. one of the small tubes leading into the lungs from a bronchus
- 8. air sacs in the lungs
- 12. of light, cannot pass through an object or be reflected from it.
- 13. something that can be broken down naturally by bacteria and fungi
- 16. a pair of muscles that work as a team; the contraction of one of the muscles causes bones at a joint to move in one direction, and the contraction of the other muscle causes movement in the opposite direction
- 18. useful materials made from natural renewable sources and not from oil
- 19. increase of the concentration of a substance as you go up a food chain
Down
- 1. a type of joint where one bone has a ball-shaped end that fits into a socket on the other bone; it allows a circular movement
- 4. chemical reactions inside cells, where oxygen is used to break down glucose and release energy.
- 7. the liquid part of blood
- 8. one of the tiny air-filled spaces inside lungs; also called an alveolus
- 9. features of organisms that help them to live and reproduce in their habitat
- 10. using muscles to make movements that cause air to move in and out of the lungs
- 11. one of the two tubes that branch from the trachea, and which carry air into the lungs
- 14. a comparison that helps to explain something
- 15. chemicals produced by white blood cells, which kill pathogens
- 17. not having enough haemoglobin in the blood, so not enough oxygen is delivered to respiring cells