Arrange the following in the order in which they occur in the problem of ozone depletion:
(A) More ultraviolet (UV) radiation comes to Earth.
(B) CFCs from air-conditioners and refrigerators lead to high levels of chlorine compounds in the stratosphere.
(C) Skin cancer and damage to other living organisms occur.
(D) The amount of ozone in the stratosphere falls.
Choose the correct answer from the options given below:
Answer & explanation
Correct answer: option 3
The correct answer is Option (3) → (B), (D), (A), (C)
Ozone depletion works as a chain of cause and effect.
(B) CFCs from air-conditioners and refrigerators lead to high levels of chlorine compounds in the stratosphere. — CFCs are the origin of the chlorine compounds.
(D) The amount of ozone in the stratosphere falls. — These compounds reduce the ozone in the stratosphere.
(A) More ultraviolet (UV) radiation comes to Earth. — A thinner ozone layer lets more UV radiation through.
(C) Skin cancer and damage to other living organisms occur. — The UV radiation then damages living organisms.
NCERT (2026-27): “Box 7.2: Ozone Depletion Ozone depletion refers to the phenomenon of reductions in the amount of ozone in the stratosphere. The problem of ozone depletion is caused by high levels of chlorine and bromine compounds in the stratosphere. The origins of these compounds are chlorofluorocarbons (CFC), used as cooling substances in air-conditioners and refrigerators, or as aerosol propellants, and bromofluorocarbons (halons), used in fire extinguishers. As a result of depletion of the ozone layer, more ultraviolet (UV) radiation comes to Earth and causes damage to living organisms. UV radiation seems responsible for skin cancer in humans; it also lowers production of phytoplankton and thus affects other aquatic organisms. …” |