NCERT Exemplar for Class 7 Science Solutions Chapter 9 Soil

Multiple Choice Questions

1. The microorganisms present in the soil require moisture (water) and nutrients for growth and survival. Choose from the options below the habitat (place) where the soil has plenty of water and nutrients.

(a) Desert

(b) Forest

(c) Open field

(d) Cricket ground

Ans: (b) Forest

2. Availability of water and minerals in the soil for maximum absorption by roots is in the 

(a) B-horizon

(b) C-horizon

(c) A-horizon

(d) surface of soil

Ans: (c) A-horizon

3. Soil conservation measures are mainly aimed at protecting which of the following?

(a) Plants

(b) Topsoil

(c) Subsoil

(d) Soil organisms

Ans: (b) Top Soil

4. Read the following statements with reference to soil.

(i) Weathering is a very fast process of soil formation.

(ii) Percolation of water is faster in sandy soils.

(iii) Loamy soil contains only sand and clay.

(iv) Top soil contains the maximum amount of humus.

Choose the correct statements from the above.

(a) (ii) and (iv) 

(b) (i) and (iii)

(c) (ii) and (iii) 

(d) (i) and (ii)

Ans: (a) (ii) and (iv)

Very Short Answer Questions

5. Soil has particles of different sizes. Arrange the words given below in increasing order of their particle size.

Rock, Clay, Sand, Gravel, Silt

Ans: The following words are listed in ascending order of particle size: 

Clay < Silt < Sand < Gravel < Rock

6. The components of loamy soil are ______, ______ and ______. 

Ans: sand, slit and clay. 

7. Read the following statements and give the appropriate terms for each of them.

(a) The process of breakdown of rocks by the action of wind, water, sunlight.

Ans: Weathering

(b) Removal of top soil during heavy rains or strong winds.

Ans: Soil erosion

(c) Accumulation of wastes in the soil generated by human activity which alter the features of soil.

Ans: Soil pollution

(d) The process of movement of water into deeper layers of soil.

Ans: d) Percolation

8. Unscramble the following jumbled words related to soil.

(a) SUHUM

Ans: HUMUS

(b) ILOS FIPROLE

Ans: SOIL PROFILE

(c) ZOINORH

Ans: HORIZON

(d) MOAL

Ans: LOAM

(e) GINRHETWEA 

Ans: WEATHERING

(f) ATONIERPCL

Ans: PERCOLATION

Short Answer Questions

9. Which of the following situations – ‘A’ or ‘B’ – is advantageous for absorption of water and minerals? Why?

Situation ‘A’ : Growth and branching of roots in the C-horizon.

Situation ‘B’ : Growth and branching of roots in A and B horizons.

Ans: The absorption of water and minerals by plants is better in Situation 'B.' Horizon-A and horizon-B are the reasons behind this. Minerals, water, and humus abound in these horizons.

10. How can a farmer convert acidic soil to neutral soil?

Ans: Acidic soil can be converted to neutral soil by adding a small amount of slaked lime solution or fast lime solution to the soil.

11. Is it a good practice to remove grass and small plants that are growing in an open, unused field? Give reason to support your answer.

Ans: No, because the surface of soil is covered by the plants. The soil particles are connected by their roots, which keep them in place.

12. A man digging a pit found that he could dig with ease initially but digging became difficult as he went deeper. He could not dig beyond a depth of 5 feet. Provide a suitable scientific explanation.

Ans: The soil in the upper layer is porous and easy to excavate. He was only able to dig to a depth of 5 feet because he encountered boulders and rough soil as he dug deeper, making digging difficult.

13. Locate the following zones given as boxed items in Figure 9.1 which shows a diagram of soil profile. 

Top soil, Subsoil, C-horizon, Bedrock

Ans:

14. Rajasthan is a desert state in India. Once while travelling to Rajasthan by train, Boojho observed several streams and rivulets of rainwater during the journey but to his surprise he did not see streams of water in the desert region even during rains. Help Boojho find a suitable explanation for this.

Ans: Rocks and sand cover a huge portion of the desert. When rainwater falls on the ground, it instantly percolates downhill through the crevices between the sand particles. As a result, during the rainy season, the streams of water in the deserts are not clear.

15. Match the animals in Column I with their natural place of dwelling (habitat) in Column II.

Ans: 

Long Answer Questions

16. Continuously water-logged soils are disadvantageous for plant growth. Why? 

Ans: The foremost functions of roots are water absorption and uptake of oxygen from the pore vicinity of the soil. However, in waterlogged soils, water holds up the gaps that are present between the soil particles and further pushes the oxygen gas in the atmosphere. As a result, the roots are deprived of oxygen, which has an impact on root and plant growth.

17. Why is soil erosion relatively less in dense forests as compared to barren, open fields?

Ans: There are many trees in a dense forest. In addition, just a small amount of sunshine penetrates the land. Rainwater does not fall on the ground because of this type of leaf layering. The tree's roots link and adhere to the soil particles together.

Fields, on the other hand, are open in barren areas. The dirt is exposed to the rainwater that is falling. The clash of raindrops causes soil particles to become mobile. They are then carried away by the flow of water. Finally, the rushing water erodes the soil surface, causing erosion to worsen.

18. Gardeners gently dig up the soil around the roots of garden herbs (plants) frequently. Give reasons.

Ans: The reasons are as follows: 

a) To get rid of the weeds.

c) For the development of roots.

d) For simple water percolation.

c) To allow air to penetrate the soil's deeper layers.

19. In towns and cities, generally, the bore wells have to be dug very deep to get water as compared to bore wells dug in villages. Give suitable reasons.

Ans: As per the stated situation,  

a) This is due to excessive water consumption, which depletes groundwater.

b) Towns and cities possess large expanses of land with asphalted roads and concreted soils. As a result, rainwater is unable to penetrate into the groundwater system to replenish it. As a result, the water level beneath the ground continues to fall. Large expanses of open soil surface can be found in villages or comparable locations. At that location, there are only a few asphalt roads and concrete surfaces. As a result, a bigger surface area of soil is accessible for water or rain to quickly seep into the soil and replenish the subsurface water supply. As a result, water drains from even shallow bore wells.

20. Several terms related to soil are hidden in the squares given as Figure 9.2. Spot them and make a list. The two examples are given for you.

Ans: 

What is NCERT Exemplar for Chapter 9- Soil of Class 7 Science About?

NCERT stands for the National Council of Educational Research and Training. It is the institution that determines the syllabus and textbooks used for many state boards across the country as well as the national level board of the CBSE. Its textbooks are also used as the main ones for the JEE Main and JEE Advanced.

NCERT Exemplar is one of the workbooks that the NCERT has created. This book contains several questions based on the chapters covered in the main textbooks. The questions in the Exemplar workbooks are of a slightly higher difficulty level as compared to the questions in the regular textbooks. This is done to encourage students to get used to higher-level questions and hopefully encourage them to study harder to solve these questions. NCERT Exemplar Science is a workbook series that has questions based on the science syllabus for different years.

Benefits of Downloading Class 7 NCERT Exemplar Science Chapter 9 Solutions

The Class 7 NCERT Exemplar Science Chapter 9 Solutions provided by Vedantu have been compiled by experts in the subject matter. Therefore, you do not have to worry about the accuracy of the answers at all. You can safely use these solutions to aid in your studies for this chapter of the syllabus.