laboursonline – MCQs, Mock Tests | NCERT Class 9 Class 9 Science Chapter 14 Natural Resources

The atmosphere of the Earth is heated by radiations which are mainly

1. radiated by the Sun
2. re-radiated by land
3. re-radiated by water
4. re-radiated by land and water

✅ Correct Answer: 4

If there were no atmosphere around the Earth, the temperature of the Earth will

1. increase
2. go on decreasing
3. increase during day and decrease during night
4. be unaffected

✅ Correct Answer: 3

What would happen, if all the oxygen present in the environment is converted to ozone?

1. We will be protected more
2. It will become poisonous and kill living forms
3. Ozone is not stable, hence it will be toxic
4. It will help harmful Sun radiations to reach Earth and damage many life forms.

✅ Correct Answer: 2

One of the following factors does not lead to soil formation in nature

1. the Sun
2. water
3. wind
4. polythene bags

✅ Correct Answer: 4

The two forms of oxygen found in the atmosphere are

1. water and ozone
2. water and oxygen
3. ozone and oxygen
4. water and carbon dioxide

✅ Correct Answer: 3

The process of nitrogen-fixation by bacteria does not take place in the presence of

1. molecular form of hydrogen
2. elemental form of oxygen
3. water
4. elemental form of nitrogen

✅ Correct Answer: 2

Rainfall patterns depend on

1. the underground water table
2. the number of water bodies in an area
3. the density pattern of human population in an area
4. the prevailing season in an area

✅ Correct Answer: 2

Among the given options, which one is not correct for the use of large amount of fertilisers and pesticides?

1. They are eco-friendly
2. They turn the fields barren after some time
3. They adversely affect the useful component from the soil
4. They destroy the soil fertility

✅ Correct Answer: 1

The nitrogen molecules present in air can be converted into nitrates and nitrites by

1. a biological process of nitrogen fixing bacteria present in soil
2. a biological process of carbon fixing factor present in soil
3. any of the industries manufacturing nitrogenous compounds
4. the plants used as cereal crops in field

✅ Correct Answer: 1

One of the following processes is not a step involved in the water-cycle operating in nature

1. evaporation
2. transpiration
3. precipitation
4. photosynthesis

✅ Correct Answer: 4

The term “water-pollution” can be defined in several ways. Which of the following statements does not give the correct definition?

1. The addition of undesirable substances to water bodies
2. The removal of desirable substances from water bodies
3. A change in pressure of the water bodies
4. A change in temperature of the water bodies

✅ Correct Answer: 3

Which of the following is not a greenhouse gas?

1. Methane
2. Carbon dioxide
3. Carbon monoxide
4. Ammonia

✅ Correct Answer: 4

Which step is not involved in the carbon-cycle?

1. Photosynthesis
2. Burning of fossil fuels
3. Respiration
4. Burning of fossil fuels

✅ Correct Answer: 2

‘Ozone-hole’ means

1. a large sized hole in the ozone layer
2. thinning of the ozone layer
3. small holes scattered in the ozone layer
4. thickening of ozone in the ozone layer

✅ Correct Answer: 2

Ozone-layer is getting depleted because of

1. excessive use of automobiles
2. excessive formation of industrial Units
3. excessive use of man-made compounds containing both fluorine and chlorine
4. excessive deforestation.

✅ Correct Answer: 3

Which of the following is a recently originated problem of environment?

1. Ozone layer depletion
2. Greenhouse effect
3. Global warming
4. All of the above

✅ Correct Answer: 4

When we breathe in air, nitrogen also goes inside along with oxygen. What is the fate of this nitrogen?

1. It moves along with oxygen into the cells
2. It comes out with the CO2 during exhalation
3. It is absorbed only by the nasal cells
4. Nitrogen concentration is already more in the cells so it is not at all absorbed.

✅ Correct Answer: 2

Top-soil contains the following

1. Humus and living organisms only
2. Humus and soil particles only
3. Humus, living organisms and plants
4. Humus, living organisms and soil particles.

✅ Correct Answer: 4

Choose the correct sequences

1. CO2 in atmosphere → decomposers → organic carbon in animals → organic carbon in plants
2. CO2 in atmosphere → organic carbon in plants → organic carbon in animals → inorganic carbon in soil
3. Inorganic carbonates in water organic carbon in plants → organic carbon in animals → scavengers
4. Organic carbon in animals → decomposers → CO2 in atmosphere → organic carbon in plants

✅ Correct Answer: 2

Major source of mineral in soil is the

1. parent rock from which soil is formed
2. plants
3. animals
4. bacteria

✅ Correct Answer: 1

Total Earth’s surface covered by water is

1. 75%
2. 60%
3. 85%
4. 50%

✅ Correct Answer: 1

Biotic component of the biosphere is not constituted by

1. producers
2. consumers
3. decomposer
4. air

✅ Correct Answer: 4

An increase in carbon dioxide content in the atmosphere would not cause

1. more heat to be retained by the environment
2. increase in photosynthesis in plants
3. global warming
4. abundance of desert plants

✅ Correct Answer: 4

Oxygen is returned to the atmosphere mainly by

1. burning of fossil fuel
2. respiration
3. photosynthesis
4. fungi

✅ Correct Answer: 3

Oxygen is returned to the atmosphere mainly by

1. burning of fossil fuel
2. respiration
3. photosynthesis
4. fungi

✅ Correct Answer: 3

Low visibility during cold weather is due to

1. formation of fossil fuel
2. unbumt carbon particles or hydrocarbons suspended in air
3. lack of adequate power supply
4. none of these

✅ Correct Answer: 2

Growth of lichens on barren rocks is followed by the growth of

1. moss
2. ferns
3. gymnosperms
4. algae

✅ Correct Answer: 1

Marked temperature changes in an aquatic environment can affect

1. breeding of animals
2. more growth of aquatic plants
3. process of digestion in animals
4. availability of nutrients.

✅ Correct Answer: 1

Soil erosion can be prevented by

1. raising forests
2. deforestation
3. excessive use of fertiliser
4. overgrazing by animals

✅ Correct Answer: 1

What happens when rain falls on soil without vegetational cover?

1. Rain water percolates in soil efficiently
2. Rain water causes loss of surface soil
3. Rain water leads to fertility of the soil
4. Rain water does not cause any change in soil

✅ Correct Answer: 2

Oxygen is harmful for

1. ferns
2. nitrogen fixing bacteria
3. chara
4. mango tree

✅ Correct Answer: 2