Tag: evs - i

Questions Related to evs - i

............ possesses carnassial teeth.

  1. Elephant

  2. Zebra

  3. Horse

  4. Dog


Correct Option: D
Explanation:

Carnassial tooth is the fourth premolar. In wild canines, it is the main tooth used to break up or crush hard material in their diet such as bones or large pieces of meat. 

Which one of the following is not a method of soil conservation?

  1. Mulching

  2. Overgrazing

  3. Strip cropping

  4. Crop rotation


Correct Option: B
Explanation:

Soil conservation is the process of prevention of soil erosion and to prevent the soil from becoming infertile.  In mulching, a protective layer is placed over the soil such as straw, grasses etc., which helps in retaining soil moisture and also regulates soil temperature. Strip cropping is a process in which field is divided into strips and different crops are grown in alternate strips to preserve soil fertility. Crop rotation means growing of different types of crops on the same field in succession which prevents the depletion of nutrients from the soil. Overgrazing or intense grazing will erode the soil.

Thus, the correct answer is option B.

In hilly areas, erosion is minimized by

  1. Terracing

  2. Manuring

  3. Ploughing

  4. Mixed cropping


Correct Option: A
Explanation:

Soil erosion is removal of top soil by agency of water (water erosion) and wind (wind erosion). One of the methods for soil conservation against soil erosion is terracing. In terracing, slope is divided into a number of flat fields for slowing down the flow of water. Terracing is very effective in hilly areas for control of soil erosion.

Soil erosion can be prevented by

  1. Overgrazing

  2. Removal of vegetation

  3. Afforestation

  4. Increasing birds population


Correct Option: C
Explanation:
Soil erosion can be prevented by afforestation and reforestation. Reforestation is restoration of forests, which have been destroyed by deforestation, while afforestation is planting of new forests. Plants hold soil with there roots and thus prevent erosion.
So, the correct answer is 'Afforestation'

Soil pollution can lead to water pollution

  1. True

  2. False


Correct Option: A
Explanation:
  • The contamination of soil with solid waste, acid rain excess of fertilizers, Insecticides, and herbicides is called soil pollution.
  • Soil pollution can lead to water pollution if toxic chemicals leach(drain away from the soil) into groundwater, or if contaminated runoff reaches streams, lakes, or oceans.
  • Hence Soil pollution can lead to water pollution is a true statement.
  • So, the correct answer is 'True'.

Mulching is helpful in

  1. Increasing soil fertility

  2. Improvement of soil structure

  3. Moisture conservation

  4. Better crops


Correct Option: C
Explanation:

Mulching refers to the covering of harvested field with plant litter or polythene of low density, in order to decrease run off, prevent the growth of weeds and retention of water. It protects the roots from seasonal variations.During initial stages of growth, mulching helps to maintain a stable temperature for proliferation of seedling.

Soil conservation is achieved through

  1. Restricted human activities

  2. Good plant cover

  3. Wind screen

  4. Ploughing


Correct Option: B
Explanation:

Soil erosion is removal of top soil by agency of water (water erosion) and wind (wind erosion). Soil erosion is of two types- natural and anthropogenic. 

Natural or geological erosion is extremely slow removal of top soil due to rain water or wind. 
Anthropogenic soil erosion is caused by removal of plant cover through over grazing, tree felling, leaving the soil unprotected during agricultural operations. 
Thus, soil conservation can be achieved through good plant cover.

The management of biosphere in such a way that it may yield one greatest suitable benefit to present generation while maintaining its potential to meet the needs of future generation is 

  1. Conservation

  2. Afforestation

  3. Fossilization

  4. Over-exploitation


Correct Option: B
Explanation:

Afforestation is the act of planting trees in a barren land or converting a farmland to a forest in order to use the trees for commercial purposes. Many programs are organised by the government as well as non-government associations to plant trees and thus improving biodiversity.

So, the correct answer is option B.

Soil erosion can be prevented by 

  1. Over grazing

  2. Removal of vegetation

  3. Afforestation (plantation)

  4. Increasing bird population


Correct Option: C
Explanation:

Afforestation is the process of establishing a forest on land, that has not been a forest for a long time by planting trees or their seeds. Soil erosion is when the soil is blown away by the wind or washed away by the rain. Roots of trees or plants hold the soil. Thus, when more trees are planted their roots do not allow the soil to be blown or washed away and prevent soil erosion.

Soil conservation is the process where 

  1. Soil is aerated

  2. Sterile soil is converted into fertile soil

  3. Soil is protected against loss

  4. Both B and C


Correct Option: D
Explanation:

Soil conservation is the prevention of soil from erosion or reduced fertility caused by overuse, acidification, salinization or other chemical soil contamination. Techniques for improved soil conservation include crop rotation, cover crops, conservation tillage and planted windbreaks, that affect both erosion and fertility.