Ozone can be destroyed by a number of free radical catalysts; the most important are:
I. OH^-
II. NO^-
III. Cl^-
IV. Br^-

Of these, human activity has drastically increased the levels of:
1. Only III
2. Only III and IV
3. Only I and II
4. I, II, III and IV

Which of the following is not one of the prime health risks associated with greater UV radiation through the atmosphere due to depletion of stratospheric ozone?
1. Reduced Immune System
2. Damage to eyes
3. Increased liver cancer
4. Increased skin cancer

World Ozone Day is celebrated on
1. 5th June
2. 22nd April
3. 16th September
4. 21st April

Montreal protocol which calls for appropriate action to protect the ozone layer from human activitieswas passed in year
1. 1985
2. 1986
3. 1987
4. 1988

Which one of the following is a wrong statement?
1. Most of the forests have been lost in tropical areas.
2. Ozone in upper part of atmosphere is harmful to animals.
3. Greenhouse effect is a natural phenomenon.
4. Eutrophication is a natural phenomenon in freshwater bodies.

In stratosphere, which of the following elements acts as a catalyst in degradation of ozone and releaseof molecular oxygen?
1. Carbon
2. Oxygen
3. Fe
4. CI

Depletion of which gas in the atmosphere can lead to an increased incidence of skin cancers:
1. Methane
2. Nitrous oxide
3. Ozone
4. Ammonia

Montreal Protocol aims at
1. Control of ${\mathrm{CO}}_2$ emission
2. Reduction of ozone depleting substances
3. Biodiversity conservation
4. Control of water pollution

''Good ozone'' is found in the:
1. Ionosphere
2. Mesosphere
3. Troposphere
4. Stratosphere