IS_Unit7_Unit_exercise_E

A1. Starch is the food produced in photosynthesis and it can be used by the plant immediately.

• True

• False

A2. When we breathe, gas exchange takes place at the nasal cavity.

• True

• False

[E] A3. The tar in cigarette smoke causes the cilia along the airway to stick together, and also increases mucus production.

• True

• False

A4. Carbon dioxide is a greenhouse gas.

• True

• False

A5. Planting more trees can help slow down global warming.

• True

• False

B1. In an experiment, two burning candles were covered by two bell jars, X and Y. A potted green plant was also placed in jar X. Both set-ups were placed under the Sun.

Which of the following statements is correct?

• A. The candle in jar X will go out first.

• B. The candle in jar Y will go out first.

• C. Both candles will go out at the same time.

• D. Both candles will not go out within 30 minutes from the start of the experiment.

B2. Which of the following is the ultimate source of energy for all food chains?

• A. Producers

• B. Consumers

• C. The Sun

• D. Humans

[E] B3. The chemical equation above summarizes the process of photosynthesis.

Which of following statements about the process are correct?

(1) The total mass of the substances involved is a constant.

(2) The total numbers of molecules on the two sides of the equation are the same.

(3) Energy is conserved in the process. It only changes from one form to another.

• A. (1) and (2) only

• B. (1) and (3) only

• C. (2) and (3) only

• D. (1), (2) and (3)

B4. Which equation summarizes the process of respiration? (TIMSS 2011)

• A. water + carbon dioxide + energy → sugar + oxygen

• B. oxygen + sugar → carbon dioxide +

  water + energy

• C. carbon dioxide + oxygen + water →

  sugar + energy

• D. sugar + carbon dioxide + energy →

  oxygen + water

C1(a). What are process I, process II, gas X and gas Y?

• A. process I: respiration; process II: photosynthesis; gas X: carbon dioxide; gas Y: carbon dioxide

• B. process I: photosynthesis; process II: respiration; gas X: oxygen; gas Y: carbon dioxide

• C. process I: respiration; process II: photosynthesis; gas X: carbon dioxide; gas Y: carbon dioxide

• D. process I: photosynthesis; process II: respiration; gas X: carbon dioxide; gas Y: oxygen