Worksheet Solutions: Soil

MCQs

Question 1: Rocks break into smaller pieces due to:
(a) force of owing water
(b) weather changes
(c) force of wind
(d) all of these

Correct Answer is Option D.

Rocks break into smaller pieces due to the force of owing water, weather changes, force of wind.

Question 2: Which of these are the lightest?
(a) Humus
(b) Sand
(c) Clay
(d) Gravel

Correct Answer is Option B.

Sand has the largest particles and settles fast.

Question 3: Which of these animals lives in the soil?
(a) Earthworm
(b) Owl
(c) Butterfly
(d) All of these

Correct Answer is Option A.

Earthworms and their relatives live anywhere there is moist soil and dead plant material.

Question 4: Which of these has the smallest pieces?
(a) Clay soil
(b) Sandy soil
(c) Humus
(d) Loam

Correct Answer is Option A.

The main kinds of rock particles present in topsoil depending on the size of the particles are clay (smallest particles).

Question 5: Which of these is obtained from things we get from the soil?
(a) Plastics
(b) Metals
(c) Petrol
(d) All of these

Correct Answer is Option B.

True & False

Question 6:

• Long ago there was only soil on the earth, and no rocks. False
• Humus is made from rocks. False
• We depend on the soil for most of our needs. True
• Different kinds of rocks break to produce different kinds of soil. True
• Clay has the largest rock pieces. False
• The colour of soil depends on the minerals present in rocks. True

EduRev Tips:

• Long ago there were only rocks on the earth, and no soil.
• Humus is composed of decaying animals, such as insects, and other organisms, such as mushrooms.
• Soil is our life support system. Soils provide anchorage for roots, hold water and nutrients.
• Different kinds of rocks break to produce different kinds of soil.
• The main kinds of rock particles present in topsoil depending on the size of the particles are clay (smallest particles).
• Soil color is produced by the minerals present and by the organic matter content. Yellow or red soil indicates the presence of oxidized ferric iron oxides.

Match the following

Question 7:
(a) Top soil           (i) Plant grown on a large scale commercially
(b) Loam              (ii) Uppermost layer of soil
(c) Crop               (iii) Mixture of sand and clay
(d) Pore space     (iv) A yellow coloured soil
(e) Sand               (v) Empty spaces between the soil particles

(a) Top soil -  (ii) Uppermost layer of soil

(b) Loam - (iii) Mixture of sand and clay

(c) crop - (i) Plant grown on a large scale commercially

(d) pore spaces - (v) Empty spaces between the soil particles

(e) Sand - (iv) A yellow coloured soil

Fill in the blanks

Question 8:

• The top layer of soil, known as topsoil, the Humus.
• The colour of soil depends on the Minerals present in it.
• All plants grow well if Organic fertilizer is added to the soil.
• The Fertile the soil, the more humus it contains.
• Sand soil has the largest particle size, followed by silt and clay soils.

EduRev Tips:

• Soil is usually layered. The uppermost layer is called topsoil and this layer contains humus, plant roots, and living creatures. 
• Soil color is produced by the minerals present and by the organic matter content. Yellow or red soil indicates the presence of oxidized ferric iron oxides.
• Organic fertilizer sources include compost, aged manure, rock phosphate, soybean meal, and fish meal. 
• Soil is usually layered. The uppermost layer is called topsoil and this layer contains humus, plant roots, and living creatures. The more humus found in topsoil, the more nutrient rich the topsoil and the better the conditions for growing plants.
• The particles that make up soil are categorized into three groups by size: sand, silt, and clay. Sand particles are the largest and clay particles the smallest.

Answer the following questions in brief

Question 9: What causes rocks to break?

Rock abrasion occurs when rocks collide with one another or rub against one another. Collisions, if they are strong enough, can cause pieces of rock to break into two or more pieces, or cause small chips to be broken off a large piece.

Question 10: Why do most plants grow well in loam?

Loam helps plants to grow better. This is because loam is a mix of sand and clay. It contains the right amount of air and can hold water well.

Question 11: How is soil formed?

Soil is formed by breaking down rocks by the action of wind, water and climate. The bigger pieces of rocks get converted into small pieces of soil.

Question 12: How is soil useful to us?

Soil is very important for us. Plants grow in the soil. Our food crops also grow in the soil. We make many useful items such as bricks, tiles and pots from soil.