Environmental Issues MCQ

This set of Class 12 Biology Chapter 16 Multiple Choice Questions & Answers (MCQs) focuses on “Environmental Issues”. These MCQs are created based on the latest CBSE syllabus and the NCERT curriculum, offering valuable assistance for exam preparation.

1. In which part of the atmosphere is the good ozone found?
a) Ionosphere
b) Stratosphere
c) Lithosphere
d) Hydrosphere
View Answer

Answer: b
Explanation: The stratosphere found in the upper layer of the atmosphere has good ozone. This layer acts as a shield and absorbs the harmful, injurious ultraviolet (UV) radiations from the sun.

2. How is the thickness of the ozone in a column of air from the ground to the top of the atmosphere measured?
a) Dobson units
b) Hertz
c) Centimeter
d) Ampere
View Answer

Answer: a
Explanation: Dobson unit (DU) is used to measure the thickness of the ozone in a column of air from the ground to the top of the atmosphere. A layer of pure ozone that is 0.01 mm thick at standard temperature and pressure is equivalent to one Dobson unit.

3. Who enhances the degradation of ozone?
a) Hydrogen
b) Chlorofluorocarbons
c) Oxygen
d) Water vapors
View Answer

Answer: b
Explanation: Chlorofluorocarbons (CFCs) enhances the degradation of ozone by disturbing the cycle of ozone formation. CFCs upon entering in stratosphere react with UV and release chlorine ions. These ions act as catalysts and degrade ozone releasing molecular oxygen.

Note: Join free Sanfoundry classes at Telegram or Youtube

4. In which region is the depletion of ozone particularly marked?
a) Equatorial region
b) Temperate region
c) Tropical region
d) Antarctic region
View Answer

Answer: d
Explanation: The stratosphere found in the upper layer of the atmosphere has good ozone. This layer acts as a shield and absorbs the harmful, injurious ultraviolet (UV) radiations from the sun. In the Antarctic region, the depletion of ozone particularly marked.

5. What does the continuous depletion of ozone lead to?
a) Proper rains
b) Ozone formation
c) Ozone hole
d) Good yield
View Answer

Answer: c
Explanation: Due to the continuous degradation of ozone, the depletion of ozone occurs. This thinning in the layer of ozone is known as the ozone hole.

Take Biology - Class 12 Practice Tests - Chapterwise!
Start the Test Now: Chapter 1, 2, 3, 4, 5, 6, 7, 8, 9, 10

6. Which of the following is an effect of the high dose of UV-B?
a) Night-blindness
b) Snow-blindness
c) Fatigue
d) Nausea
View Answer

Answer: b
Explanation: UV-B is the shorter wavelength of UV. It penetrates deeper into the skin causing aging of skin and cancers. A high dose of UB-B leads to snow-blindness, also known as arc eye or photokeratitis.

7. Which protocol was signed to control the emission of ozone-depleting substances?
a) France Protocol
b) Germany Protocol
c) India Protocol
d) Montreal Protocol
View Answer

Answer: d
Explanation: To control the emission of ozone-depleting substances an international treaty, known as the Montreal Protocol, was signed. It was signed in 1987 by more than 175 countries in Montreal (Canada).

More MCQs on Class 12 Biology Chapter 16: