Biology [2 Mark Question Answer]

Carbon dioxide gas is released into the atmosphere in a large quantity. Excessive release of carbon-dioxide leads to greenhouse effect that increases the average temperature of earth. It is also referred to as the global warming. Amount of carbon-dioxide has increased by 28% in the last one hundred years which is attributed to burning of fossil fuels like coal, gas and oil.

Chlorofluorocarbons (CFCs) are nontoxic, nonflammable chemicals containing atoms of carbon, chlorine, and fluorine. They are used in the manufacture of aerosol sprays, blowing agents for foams and packing materials, as solvents, and as refrigerants. CFC = s react with sunlight in the earth’s stratosphere to break down the protective ozone layer, a layer of gas that shields the earth’s surface from damaging UV-B rays

Effects of Acid Rain:

1. Acid rain increases acidity in the soil and destroys forests and crops.
2. It corrodes fences, buildings, monuments, bridges and statues.
3. It affects the human nervous system by causing neurological diseases.
4. It poses a serious threat to human health, since it contaminates air and water.

Radiation can lead to severe health hazards. Effects of non-ionizing radiation at low level are uncertain but of ionizing radiation at high level can cause cancer and increase in chromosome damage.

Some atoms (for instance uranium) are unstable and tend to change into other types of atoms. When they change them release energy and sometimes particles. These atoms are radioactive and the energy or particles released is radiation. Radiation can damage materials, including living tissue.

Replacement of coal by the oil fuel has increased the problem of pollution. The presence of oil in a water course is undesirable since it creates aesthetic problems. It has a tendency to spread over the surface of water; diffusion of oxygen into water is inhibited and re-aeration of water is affected.

The pressure horn Causes noise pollution which increases blood pressure, disturbs concentration, lowers working capacity and may lead to nervous disorders. Hence, use of pressure horn is prohibited near certain places like near hospitals, schools and residential complexes etc.