q: Which type of pollution is most harmful to lungs?
Options:
- (A) Lead
- (B) air
- (C) Cars
- (D) oil
- (E) acid
- (F) CFCs
- (G) SO2
- (H) mold
a: (B)... Explanation: Air pollution harms the respiratory and circulatory systems. Exposure to ozone can diminish lung function and increase susceptibility to respiratory infection. Exposure to air pollution can harm the lungs. That's why the answer is (B).

q: What do phytoplankton and algae need in order to make energy?
Options:
- (A) water
- (B) glucose
- (C) food
- (D) sunlight
- (E) bacteria
- (F) Light
- (G) adding heat
- (H) The Sun
a: (D)... Explanation: Phytoplankton are bacteria and algae that use sunlight to make food. Food gives energy. Phytoplankton and bacteria are algae that use sunlight to make energy. That's why the answer is (D).

q: Aging is associated with degrading:
Options:
- (A) Most plants
- (B) an object
- (C) Acids
- (D) telomeres
- (E) layers of fat
- (F) Chlorophyll
- (G) vegetation
- (H) the skin
a: (D)... Explanation: Aging is associated with the death of cells. Telomeres degrade as the cells divide and their shortening causes cell death. Aging is associated with degrading telomeres. That's why the answer is (D).

q: What may become unbalanced if the rate of breathing is too fast or too slow?
Options:
- (A) meiosis
- (B) rain levels
- (C) photosynthesis
- (D) blood acidity
- (E) an organism's body
- (F) Veins and arteries.
- (G) kinetic energy
- (H) swamp vegetation
a:
(D)... Explanation: Blood pH may become unbalanced if the rate of breathing is too fast or too slow. Acidity is measured with a pH meter or with pH paper strips. Blood acidity may become unbalanced if the rate of breathing is too fast or too slow. That's why the answer is (D).