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Ncert Exemplar Solutions Class 7 Science Soil
Welcome to NCTB Solutions. Here with this post we are going to help 7th class students for the Solutions of NCERT Exemplar Class 7 Science Book, Unit 9, Soil. Here students can easily find step by step solutions of all the problems for Soil, Also here our Science teacher’s are solved all the questions with easily understandable language with proper guidance so that all the students can understand easily.
Soil all Question Solutions :
Multiple Choice Questions :
Question no – (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.
Answer :
The correct answer is option – (b)
In the Forest soil has plenty of water and nutrients.
Question no – (2)
Availability of water and minerals in the soil for maximum absorption by roots is in the
Answer :
The appropriate answer is option – (c)
Availability of water and minerals in the soil for maximum absorption by roots is in the A-horizon.
Question no – (3)
Soil conservation measures are mainly aimed at protecting which of the following?
Answer :
The answer is option – (b)
Soil conservation measures are mainly aimed at protecting the Top soil.
Question no – (4)
Read the following statements with reference to soil.
Answer :
The correct answer is option – (a) (ii) and (iv)
(ii) Percolation of water is faster in sandy soils.
(iv) Top soil contains the maximum amount of humus.
Very Short Answer Questions :
Question no – (5)
Answer :
The words in increasing order of their particle size are clay, silt, sand, gravel and rock.
Question no – (6)
Answer :
The components of loamy soil are sand, clay and silt.
Question no – (7)
Answer :
(a) The process of breakdown of rocks by the action of wind, water, sunlight.
= Weathering.
(b) Removal of top soil during heavy rains or strong winds.
= Soil erosion.
(c) Accumulation of wastes in the soil generated by human activity which alter the features of soil.
= Humus.
(d) The process of movement of water into deeper layers of soil.
= Percolation.
Question no – (8)
Answer :
(a) SUHUM → Humus.
(b) ILOSFIPROLE → Soil Profile.
(c) ZOINORH → Horizon.
(d) MOAL → Loam.
(e) GINRHETWEA → Weathering.
Short Answer Questions :
Question no – (9)
Answer :
The situation ‘B’ will be more advantageous to the growth of tree as A and B horizon are rich in minerals, water and humus than compared to horizon C.
Question no – (10)
Answer :
A farmer can convert acidic soil to neutral soil by adding some amount of quicklime or slaked lime in the soil. Since they are basic in nature it will neutralize the acid and makes it harmless.
Question no – (11)
Answer :
No it’s not a good practice to remove grass and small plants that are growing in an open area since the root of these plants binds the soil together, thus preventing the top soil from soil erosion and possibly turning into a dessert.
Question no – (12)
Answer :
The two upper horizons that is A and B are mostly top soil and sub soil which are mainly composed of loose soil particles, humus and water so the man had no difficulty in digging the upper layers. But as he digs deeper he comes into contact with horizon C which is mainly composed of rocks and thus it becomes harder to dig after 5 – 6 feet.
Question no – (14)
Answer :
The deserts are mainly composed of sand particles which we all know are very porous. So when it rains in deserts water percolates through sand particles and reaches the deeper soil. That’s why we cant see stream of water in deserts.
Question no – (15)
Answer :
(a) → (vi) A horizon of moist soils.
(b) → (iv) Surface of soil.
(c) → (i) Sand and beaches.
(d) → (ii) Burrows in soil.
(e) → (iii) Deep, narrow holes in dry soils.
(f) → (v) Surface of shaded moist soils.
Long Answer Questions :
Question no – (16)
Answer :
Roots are not only involved in the process of water absorption but it also absorbs oxygen that is present between the pores of the soil particles. But during water logged conditions these Oxygen in these pores are pushed towards the atmosphere by the percolating water. These deprive the plant from sufficient oxygen requirements and thus it’s growth is hampered.
Question no – (17)
Answer :
A dense forest has a large canopy and a huge network of roots. The roots binds the soils together while the canopy prevents the falling rain water to directly hit the soil as well as reduces the speed of the passing wind. These factors together make a dense forest less vulnerable to erosion. While a barren land does not have trees so it is more prone to erosion by wind and flowing water.
Question no – (18)
Answer :
Gardeners often dig up the soil around the roots of the garden herbs in order to remove the weeds that might deprive the herb of soil nutrients, to make some space for easier percolation of water and oxygen and to allow the roots to grow properly.
Question no – (19)
Answer :
In cities and towns the bore wells have to be dug deep as a result of excessive water usage from the residents and because of the fact that surfaces of cities and towns are mostly covered with asphalt roads or concrete slabs which makes it difficult for water to percolate and replenish the ground water level. But in rural areas the surfaces are not covered with such things so water percolates much faster. So a rural bore well does not need to be dug deep as the ground water level is already high.
Other Chapter Solutions :
👉 Heat
👉 Physical and Chemical Changes
👉 Weather, Climate and Adaptation of Animals to Climate
👉 Transportation in Animals and Plants
👉 Electric Current and Its Effects
👉 Light
👉 Wastewater Story
