1. High fat or glucose, eg Mars bars, chocolate, Kendal mint cake etc.

2. Activities, heat, growth and repair.

3. Playing basketball, swimming, walking, doing homework, sleeping.

4. Oxygen is needed for respiration all the time; they may have difficulty breathing.

5.

Alike	Different
chemical energy is released	respiration involves a gradual release
oxygen is needed	respiration takes place at lower temperatures
carbon dioxide and water are made	respiration takes place in water

6. Diffuses from the lung into the blood, enters a red blood cell, carried through blood vessels with blood, diffuses into a cell.

7. Oxygen breathed in 21%, Carbon Dioxide breathed out 4%.

8. a. heartbeat increases
b. number of breaths each minute increases
c. the volume of each breath increases
d. the amount of oxygen taken in increases
e. the amount of carbon dioxide given out increases
f. the amount of energy that is used increases

9. Nadia’s father is bigger, more active, and male.

10.Increased exercise increases energy output. Regular exercise leads to a healthy appetite and increased self-esteem.