Depletion of ozone layer : Ozone layer gets depleted due to the use of chemicals called aerosol, spray propellants like chlorofluorocarbons. Depletion of ozone layer causes skin cancer in men and animals and severe damage to the plants. Direct exposure to ultraviolet radiations leads to skin and eye cancer in animals. Strong ultraviolet rays may lead to minimal growth, flowering and photosynthesis in plants. The forests also have to bear the harmful effects of the ultraviolet rays.
1. Which of the following facts are incorrect?
a. Global warming is the rise in the average temperature of the earth s climate system
b. Eutrophication is observed in water bodies
c. The greenhouse effect is a natural phenomenon
d. Ozone is harmless to breathe
2. Carbon dioxide is primarily called a greenhouse gas because
a. Traps heat
b. Traps light
c. Traps warm currents
d. None of the above
3. Depletion of the ozone layer is damaging to human health. Negative effects include
a. Skin cancers
b. Osteoporosis
c. Dyspepsia
d. None of the above
4. Areas that are under the influence of DDT may observe a decline in the population of birds. This is due to the fact that
a. Birds stopped laying eggs altogether
b. The eggs did not hatch
c. Predation of the eggs increased
d. None of the above
5. Measuring BOD (biological oxygen demand) is primarily used for
a. Estimating the types of microbes
b. Determine the level of dissolved oxygen
c. Estimating the quantity of organic matter in sewage water
d. None of the above
