WorksheetsIS_Unit7_Unit_exercise_E
Total questions: 14
Worksheet time: 7mins
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
C1(b).Through the two processes, the two gases remain almost at constant levels in Nature. What are their percentages in air?
A. gas X: 21%; gas Y: 0.03%
B. gas X: 21%; gas Y: 0.07%
C. gas X: 0.03%; gas Y: 21%
D. gas X: 0.03%; gas Y: 78%
C1(c). Many human acitivities are disrupting the balance of the two gases in Nature. Which of the following are such human activities?
(1) Cutting down trees
(2) Burning fossil fuels
(3) Volcanic eruptions
A. (1) and (2) only
B. (2) and (3) only
C. (1) and (3) only
D. (1), (2) and (3)
C2(a). When compared with traditional LED lamp, by how many percent the LED filament bulb can reduce carbon dioxide emission?
A. 71.0%
B. 50.1%
C. 40.9%
D. 29.0%
C2(b). This LED filament bulb is more environmentally friendly. Why reducing carbon dioxide emission helps reduce the harmful effects to the envrionment?
Carbon dioxide is a greenhouse gas. The increasing amount of carbon dioxide decreases the amount of oxygen in the
atmosphere. Organism may die due to suffocation. This effects the ecosystem.
Carbon dioxide is a greenhouse gas. The increasing amount of carbon dioxide in the atmosphere enhances the greenhouse effect and more heat is trapped in the atmosphere. This results in global warming , which has many possible harmful effects on the environment, such as the melting of ice at polar regions and
climate change.
Carbon dioxide is a harmful gas. The increasing amount of carbon dioxide in the atmosphere make organism inhale too much carbon dioxide, which may lead to death. This results in the gradual decrease of biodiversity in the world.
Carbon dioxide is a harmful gas. The increasing amount of carbon dioxide increases its percentage in air to the highest among all gases, which enhances the greenhouse effect. This results in global warming which may bring many possible harmful
effects on the environment, such as the melting of ice at polar regions and the rise in sea level.
