CBSE Questions for Class 9 Biology Natural Resources Quiz 3 - MCQExams.com

Over the past century, the burning of fossil fuels and other human and natural activities have released enormous amounts of heat-trapping gases into the atmosphere. 

These emissions have caused the Earth's surface temperature to rise and the oceans absorb about 80 per cent of this additional heat.

The rise in sea levels is linked to three primary factors, all induced by this ongoing global climate change. One of them is the melting of glaciers and polar ice caps. Large ice formations, like glaciers and the polar ice caps, naturally melt back a bit each summer. But in the winter, snows, made primarily from evaporated seawater, are generally sufficient to balance out the melting.

Recently, though persistently higher temperatures caused by global warming have led to greater-than-average summer melting as well as diminished snowfall due to later winters and earlier springs. 

Hence, option A is correct.

Fossil fuels  like coal, oil and gases were formed millions of years ago by action of high temperature and pressure on dead plants and animals. But these reserves are finite and are exhaustible.

So, the given statement is True.

• Groundwater is a natural resource of water that is prone to contamination due to increasing industrialization. 
• Human activities like waste disposal-private sewage disposal systems, land disposal of solid waste, municipal wastewater, industrial effluents, mine wastes, certain agricultural activities like the use of pesticides and chemical fertilizers, mining, acid rain, improper good construction, and maintenance, road salt contributes to contamination of groundwater. 
• Thus, the correct answer is option B.

• The water cycle involves the continuous movement of water on, above and below the surface of the Earth. 
• The surface water evaporates by the process of evaporation which condenses into tiny droplets that fall on the earth as rain as a source of the atmospheric cycle. 
• Surface waters and atmospheric cycles thus overlap in hydrological cycles.
  Thus, the correct answer is option A.

$$\textbf{Correct option: }$$ C

$$\textbf{ Solution: }$$

$$\textbf{ Option (A): }$$

$$\bullet$$The level of water accumulated below the ground surface is known to be the groundwater. 

$$\textbf{ Option (B): }$$

$$\bullet$$The level of water that is maintained in the soil after gravitational water is drained out is known to be the capillary water. 

$$\bullet$$This water is subjected to the laws of capillary movement

$$\textbf{ Option (C): }$$

$$\bullet$$The major source of water to the soil is precipitation. 

$$\bullet$$Precipitation is defined as the rain shower or the liquid fall in the form of frozen snow over the surface of earth. 

Hence, the correct option is (C).

• An ozone hole is a depletion of the ozone layer which is present in the stratosphere region around 26-30kms above the Earth's surface. 
• It is caused by chlorofluorocarbons (CFCs) found in air-conditioners, aerosol spray cans, refrigerants, etc. 
• CFCs can not be removed in the troposphere and moves in the stratosphere layer where it reacts with ozone, thereby releasing free chlorine atoms and causes the ozone layer to deplete. 

• A greenhouse gas is any gaseous compound in the atmosphere that is capable of absorbing infrared radiation, thereby trapping and holding heat in the atmosphere. 
• By increasing the heat in the atmosphere, greenhouse gases are responsible for the greenhouse effect.
• The most significant greenhouse gases are water vapor ($$H_2O$$), carbon dioxide ($$CO_2$$), methane ($$CH_4$$) and nitrous oxide ($$N_2O$$).

Solution:

• Correct answer is option D

• Greenhouse gasses generally traps the radiations of the earth which leads to an increase in the temperature of the earth and global warming.
• The greenhouse gasses include water vapor, chlorofluorocarbon carbon dioxide, methane, nitrous oxide, and ozone.