Tag: evs

Questions Related to evs

Choose the correct answer from the alternatives given.
The fertility of soil is reduced by

  1. ammonifying bacteria

  2. denitrifying bacteria

  3. nitrifying bacteria

  4. nitrogen fixing bacteria


Correct Option: B
Explanation:

Decomposers also break down the bodies of dead organisms resulting in nitrogen being returned to the soil as ammonia. In some conditions, denitrifying bacteria in the soil break down nitrates and return nitrogen to the air. This is usually in waterlogged soil. Hence, making it unavailable for plant roots. So, the correct option is 'Denitrifying bacteria'

Formation of plains is an example of

  1. Extrinsic

  2. Intrinsic

  3. Both A and B

  4. None


Correct Option: A
Explanation:

The forces like exogenic and endogenic can create a lot of landforms. Examples include Mountains, Plateaus, and Plains.

So, the correct option is 'Extrinsic'.

Soil contains : 

  1. Waste material

  2. Humidity

  3. Rocks

  4. Minerals


Correct Option: D
Explanation:

Soil contains minerals because they are made up of rocks by the process of weathering.

Models of vegetables are made with this soil :

  1. Sandy

  2. Sticky

  3. Rocky

  4. All the above


Correct Option: A

___________ is a source of all minerals

  1. air

  2. water

  3. wildlife

  4. soil


Correct Option: D

The lower limit of water availability is soil is known as

  1. Field capacity

  2. Hypolimnion

  3. Thermocline

  4. Wilting point


Correct Option: D

Which one is the main source of minerals essential for man and other organisms?

  1. Lithosphere

  2. Ionosphere

  3. Mesosphere

  4. Stratosphere


Correct Option: A
Explanation:

The lithosphere serves as a source of minerals. The minerals supply the basic materials, required for making a variety of commodities, which man uses daily. The lithosphere is also the major source of fuels, such as coal, petroleum and a natural gas. 

The lithosphere in combination with the hydrosphere and the atmosphere plays a vital role in the growth of plants and animals. It provides nutrients to the plants. The plants are the source of food for man and all other animals.

Materials of biological origin which are commonly used to maintain and improve soil fertility are 

  1. green manures

  2. biofertilizers

  3. bioinsecticides

  4. both (a) and (b).


Correct Option: D
Explanation:

Green manures are added to the soil to increase the productivity. Manures is of natural origin. The presence of nutrients in manure have a great role in increasing soil fertility. Biofertilizers are organisms which enrich the soil with nutrients e.g., Rhizobiumin symbiotic association with legume plants.

Soil is a component of

  1. Lithosphere

  2. Hydrosphere

  3. Atmosphere

  4. None of above


Correct Option: A
Explanation:

Lithosphere is the outer solid crust of Earth, which we call land. Its upper weathered part forms the soil.

When large patches of forests are being cleared for cultivation of crops, the environmental impact of such a practice would lead to______

  1. Soil erosion

  2. Soil conservation

  3. Soil pollution

  4. Soil fertility


Correct Option: A
Explanation:

 Deforestation is a direct cause of the erosion happening in tropical rain forests. Once plant cover is gone there are no roots to hold the soil in place during heavy tropical rains, which then wash away the topsoil and the nutrients necessary to regenerate future vegetation.