Natural Resources Test - 14

Air is a bad conductor of heat. It does not become hot or cold quickly. Thus, the atmosphere prevents a sudden decrease or increase in temperature. Since the moon is devoid of any atmosphere, the variation in its surface temperature is very large (from − 190°C to 110°C).

The correct answer is A.

Air is a bad conductor of heat. The presence of atmosphere prevents sudden changes (increase or decrease) in temperatures. Therefore, atmosphere is responsible for maintaining average temperature.

The correct answer is D.

Convection is the phenomenon of the vertical transfer of heat during which the heat is transferred by the movement of particles present in the medium. In the given case when air is heated, convection currents are set up in air that cause the outward flow of hot air and the inward flow of cold air.

The correct answer is B.

A change in the flow of water can cause different natural disasters such as droughts. However, a change in the direction of the flow of water is neither a cause nor the result of water pollution.

The correct answer is B.

The process during which rain water seeps into the ground to recharge ground water is called infiltration.

The correct answer is D.

Nitrogen fixing bacteria is found in the roots of some special plants known as leguminous plants. They form root nodules. These bacteria absorb nitrogen from the soil and convert it into nitrites and nitrates.

The correct answer is D.

Carbon dioxide is the most abundant greenhouse gas in the atmosphere apart from water vapour. Hence, it poses a serious threat to our planet by contributing to global warming.

The correct answer is C.

Ozone layer is situated in the upper atmospheres of the Earth. This layer is essential for the survival of living organisms on the Earth, as it absorbs the harmful radiation coming from the Sun.

This layer reacts with the chlorofluorocarbons (CFCs) produced by various man-made substances such as deodorants. An increase in the CFCs in the atmosphere results in the depletion of the ozone layer.

The correct answer is D.

Ozone is a poisonous gas. Therefore, statement I is correct.

CFCs are the compounds that cause a depletion of ozone layer. These compounds are composed of carbon, fluorine and chlorine. Carbon dioxide is responsible for the greenhouse effect and not for the depletion of ozone layer.

Ozone layer forms a protective shield around the Earth and does not allow harmful radiation from the Sun to enter the Earth’s surface.

Therefore, statements II and III are incorrect.

The correct answer is D.

Cutting down of trees on a large scale will result in soil erosion. The roots of plants and trees hold the soil together, thereby preventing it from getting blown away by agents such as water or wind.

The correct answer is B.

Oxygen cycle maintains the level of oxygen in the atmosphere. In the atmosphere oxygen is used mainly during the processes of combustion, respiration and formation of oxides of nitrogen, thereby leading to a decrease in the level of oxygen.

The correct answer is D.

In the process of condensation during the formation of clouds, water vapours present in the atmosphere rise up and cool down, thereby forming tiny droplets of water. These tiny droplets start accumulating around the dust particles suspended in the air and form bigger droplets. Thus, in the process of condensation, the dust particles act as the nuclei of the water droplets.

The correct answer is D.

The amount of rainfall received by a place has a direct relationship with the diversity of vegetation found in the region, provided that all the other necessary conditions (factors such as temperature, nature of soil etc.) remain the same. In the given situation, place IV receives the maximum amount of rainfall as compared to the other places. Hence, the maximum biodiversity can be expected to be found in this place.

The correct answer is D.