Natural Resources Test - 32

Intensive agriculture is basically commercial agriculture where chemical pesticides and fertilizers are used to increase the crop yield to gain more profit. Excessive use of these chemicals reduces the fertility of soil by lowering the soil quality. Thus, the correct answer is option D.

• When air is heated by radiation from the heated land or water, it rises. But since land gets heated faster than water, the air over land would also be heated faster than the air over water bodies.
• The air above the land gets heated faster and starts rising. As this air rises, a region of low pressure is created and air over the sea moves in to this area of low pressure. 
• The movement of air from one region to the other creates winds. During the day, the direction of the wind would be from the sea to the land.
• At night, both land and sea start to cool. Since water cools down slower than the land, the air above water would be warmer than the air above land. Thus, differences in temperature and pressure cause movement in the air.

So, the correct answer is option D.

Atmospheric nitrogen fixation occurs when the electrical discharge of lightning combines nitrogen and oxygen present in the atmosphere.

Nitrogen is the gas which is maximally present in the atmosphere. Up to 78% of the atmosphere contains Nitrogen gas. The second most abundant is oxygen which consists of 21% of the atmosphere. All other gases are present less than 1%.

The ozone layer is responsible for most of the absorption of harmful UV rays. Depletion of the ozone layer allows the harmful UV rays to enter the Earth's surface causing various damages to the living organisms. Exposure to UV rays can lead to skin cancer, defective eyesight, reduction in immunity, increased number of mutations, and reduction in crop yield.

When carbon dioxide and other air pollutants are collected in the atmosphere they absorb sunlight that has bounced from the earth’s surface. This leads to an increase in the earth's average surface temperature and is called global warming. When there is no effect of global warming, the temperature of the earth's surface will decrease. 

• The assimilation of oxygen from the atmosphere to the biosphere is called as oxygen cycle. 
• As shown in the given diagram, oxygen in the atmosphere is utilized by plants and animals for respiration. 
• It results in the formation of carbon dioxide and water. These are utilized by plants for photosynthesis, which results in the production of sugars and organic compounds and the release of oxygen back into the air. This cycle is then repeated. This is the oxygen cycle.

The biosphere is a narrow zone on the surface of the earth where soil, water, and air combine to sustain life. Life can only occur in this zone. From fungi and bacteria to large animals, there are several different types of life.

The biosphere can also be defined as the sum total of all ecosystems. The biosphere includes regions on, above, and below the Earth’s surface where life exists.

In the given figure, X is evaporation. Evaporation is the process of conversion of water into vapour. Water vapour rises up into the atmosphere and cools down to form clouds.