Climate Change — Homi Bhabha Class 9 Biology MCQs with Solutions
Free Homi Bhabha Class 9 Biology Climate Change MCQs with step-by-step solutions (10 questions). Part of Ecosystem & Environmental Management. Practise online on Prepizo — no login needed.
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Questions with solutions
Q1 — Climate Change · medium · theory
The trapping of heat near the Earth's surface by certain gases is called the:
A. photoelectric effect
B. greenhouse effect ✓ Correct
C. cooling effect
D. ozone effect
Solution: Greenhouse gases trap heat, keeping the Earth warm — the greenhouse effect.
Q2 — Climate Change · medium · theory
The main greenhouse gas responsible for global warming is:
A. oxygen
B. carbon dioxide ✓ Correct
C. argon
D. nitrogen
Solution: Carbon dioxide (along with methane) is a major greenhouse gas driving global warming.
Q3 — Climate Change · hard · theory
The gradual rise in the average temperature of the Earth is called:
A. condensation
B. global warming ✓ Correct
C. acid rain
D. eutrophication
Solution: Global warming is the increase in Earth's average temperature due to greenhouse gases.
Q4 — Climate Change · hard · theory
The depletion of the ozone layer is caused mainly by:
A. chlorofluorocarbons (CFCs) ✓ Correct
B. oxygen
C. water vapour
D. carbon dioxide
Solution: CFCs released from refrigerants and sprays break down ozone in the stratosphere.
Q5 — Climate Change · medium · theory
A likely effect of global warming is:
A. cooling of the oceans
B. no change in climate
C. thicker ice caps
D. melting of glaciers and a rise in sea level ✓ Correct
Solution: Rising temperatures melt glaciers and polar ice, raising sea levels.
Q6 — Climate Change · hard · theory
Which of the following would help to REDUCE global warming?
A. Increasing use of CFCs
B. Planting more trees and using renewable energy ✓ Correct
C. Burning more fossil fuels
D. Cutting down forests
Solution: Afforestation absorbs CO₂ and clean energy cuts emissions, both reducing global warming.
Q7 — Climate Change · easy · theory
Which of the following is a greenhouse gas that contributes to global warming?
A. Oxygen
B. Carbon dioxide ✓ Correct
C. Nitrogen
D. Argon
Solution: Carbon dioxide is a major greenhouse gas that traps heat in the atmosphere. Nitrogen, oxygen, and argon make up most of the air but do not trap heat significantly.
Q8 — Climate Change · medium · theory
Which statement best describes the greenhouse effect?
A. Greenhouse gases absorb and re-emit heat radiation, keeping the Earth warm ✓ Correct
B. The ozone layer reflects all heat back into space
C. Clouds are the only thing that cools the Earth
D. Greenhouse gases block incoming sunlight from reaching Earth
Solution: Greenhouse gases let sunlight in but absorb the infrared heat radiated back from the Earth and re-emit part of it downward, trapping heat and keeping the planet warm.
Q9 — Climate Change · hard · theory
Assertion (A): The melting of polar ice caps speeds up global warming. Reason (R): Bright ice reflects most sunlight, so when it melts the darker ocean and land absorb more heat.
A. Both A and R are true and R is the correct explanation of A ✓ Correct
B. A is false but R is true
C. Both A and R are true but R is not the correct explanation of A
D. A is true but R is false
Solution: Ice has high albedo and reflects sunlight; the exposed darker surfaces absorb more heat, which melts more ice. This positive feedback (reduced albedo) means R correctly explains A.
Q10 — Climate Change · hard · theory
Which of the following statements correctly distinguishes ozone-layer depletion from global warming?
A. Ozone depletion directly causes global warming and they are the same problem
B. Both are caused by the same gas, carbon dioxide
C. Ozone-layer depletion is caused mainly by CFCs, while global warming is caused mainly by greenhouse gases such as carbon dioxide ✓ Correct
D. Both are caused by a build-up of oxygen in the atmosphere
Solution: They are distinct problems. Ozone depletion is driven mainly by chlorofluorocarbons (CFCs) breaking down ozone in the upper atmosphere, whereas global warming results chiefly from heat-trapping greenhouse gases like CO2.