Biology [2 Mark Question Answer]

Effects of ozone layer depletion on humans:

• Sun burn
• Genetic disorders
• Skin cancer

Effects of noise pollution:
I. It lowers efficiency of work.
II. It disturbs sleep and leads to nervous irritability.

Measures to minimise noise pollution:
(i) Use of loud speakers should be banned.
(ii) Airports should be located away from the residential area.

Three major constituents of sewage:

• Kitchen wastes
• Sanitary waste
• Waste from agricultural lands

Prolonged noise such as the one produced by crackers :
(a) Prolonged exposure to the high decibel noise damages ear drums and can bring permanent hearing impairment.
(b) Noise pollution can lead to high blood pressure (hypertension), constant headache, lack of concentration.

Pesticides such as DDT used in agriculture:
(a) Pesticides kill soil microbes which are responsible to recycle the nutrients in the soil.
(b) Pesticides can enter the food chain and affect the health of humans as well as animals. It can cause damage to the lungs and central nervous system, failures of reproductive organs and dysfunctions of the immune system, endocrine system, and exocrine system, as well as potential cancer risks and birth defects

Rivers contaminated with sewage:
(a) A number of waterborne diseases are produced by the pathogens present in polluted water, affecting humans as well as animals.
(b) The flora and fauna of rivers, sea and oceans is adversely affected.