Tag: soil - formation and profile

Questions Related to soil - formation and profile

........ can be defined as the organic and inorganic materials on the surface of the Earth that provides the medium for plant growth.

evs mud and stones soil - formation and profile soil-nature soil profile

  1. Humus

  2. Soil

  3. Minerals

  4. Ores

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Correct Option: B

The top most layer of soil contains

biology natural resources - air, water and land soil - formation and profile soil-nature soil profile

  1. Humus, living organism and soil

  2. Human, living organism and plants

  3. Humans and soil particles

  4. Human and microorganism

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Correct Option: A
Explanation:

The top most layer of soil is said to contain and support a lot of living organisms. It also has organic manure in it that supports the growth and development of plants. 

So, option a "Humus, living organisms and soil" is the correct answer.

Soil contain rock particles

biology natural resources - air, water and land soil - formation and profile soil-nature soil profile

  1. Water and plants

  2. Minerals, organic matter, air and water

  3. Air and plants

  4. Air, water and plants

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Correct Option: B
Explanation:

The soil is formed by weathering of rocks. It contains an organic material (dead decay of leaves and plants) called humus, which makes soil fertile, and mineral by the breakdown of rocks. It also contains soil and water. Thus, the correct option is B.

Identify the constituents of soil.

evs mud and stones soil - formation and profile soil-nature soil profile

  1. Gravel

  2. Salt

  3. Mineral

  4. All of the above

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Correct Option: D
Explanation:
Soil is a major part of the natural environment, alongside air and water, and is vital to the existence of life on the planet. Soil is the result of the process of the gradual breakdown of rock, the solid geology that makes up the Earth. As rock becomes broken down through a variety of processes, such as weathering and erosion, the particles become ground smaller and smaller.
As a whole, soil is made up from four constituents: mineral material, organic material, air and water. There are considered to be three main mineral parts to soil; ‘sand’, ‘silt’ and ‘clay’. These parts give the soil its 'mineral texture'. In addition, as leaves and other organic material fall to the ground and decompose - there also forms an ‘organic’ layer. Soil scientists (or pedologists) use a series of sieves info to separate out the constituent parts in order to characterise soil by texture class.

Soil is a mixture of

evs mud and stones soil - formation and profile soil-nature soil profile

  1. Sand and clay

  2. Sand and humus

  3. Clay and humus

  4. Sand,clay and humus

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Correct Option: D
Explanation:

Soil is the upper weathered humus containing part of earth's surface, which can sustain terrestrial plant life. Soil is composed of inorganic mineral particles (45 percent), water (25 percent), air (25 percent), humus (5 percent) and variable number of living organisms. Mineral particles are of four types- (i) gravel or fine pebbles, (ii) sand or silica or quartz, (iii) silt or very fine quartz, (iv) clay or hydrated silicates of aluminium. 

Clay and humus are the main determinants of soil properties. Silt and Sand are chemically inert and do no hold water. Clay and humus produce colloidal complex for holding water and ions and forming soil crumbs.

The organic matter of soil has the value 

evs mud and stones soil - formation and profile soil-nature soil profile

  1. 25%

  2. 50%

  3. 40%

  4. 5%

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Correct Option: D

Source of maximum sulphur is

evs mud and stones soil - formation and profile soil-nature soil profile

  1. Ocean

  2. Land

  3. Rocks

  4. Lakes

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Correct Option: C
Explanation:

Sulphur is widely distributed as native deposits near volcanoes and hot springs, is a component of sulphide minerals. E.g., galena, pyrite, sphalerite, etc., and is also found in meteorites. Significant deposits exist in salt domes along the Gulf coast of the USA, and in large evaporite deposits in eastern Europe and western Asia, and are most likely the result of bacterial breakdown of sulphate minerals. The weathering of rocks will result in the production of major source of sulphur.

............... helps in maintaining the supply of nutrients to the growing plants.

evs mud and stones soil - formation and profile soil-nature soil profile

  1. Herbivores

  2. Carnivores

  3. Decomposers

  4. Omnivores

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Correct Option: C
Explanation:

All living organisms have a definite life cycle.

When an organism dies, his dead body is decayed by numerous saprophytes feeding over it. These saprophytes convert complex organic material into simple inorganic material which is then stored in the soil in the form of nutrients. When seeds of a plant grow, they receive nutrition from the soil which is absorbed by the roots of the plants. 
In this way, decomposers that decay plant and animal bodies provide the nutrition back to the soil
So, option C, 'Decomposers' is the correct option.

The rotting dead matter in the soil is called as

evs mud and stones soil - formation and profile soil-nature soil profile

  1. Decomposition

  2. Humus

  3. Petrification

  4. Minerals

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Correct Option: B
Explanation:

The dark black upper layer of soil is known as humus. It is actually the dead matter of plants and animals that have been decomposed by bacteria and fungi. This humus rich soil increases the aeration capacity of soil and also helps in the penetration of roots of plants. The decomposition of organic matter helps in bringing the plant and animal residues back to soil. The soil organisms use the organic matter its food and in the process convert in into nutrient rich humus for plant growth. 

Thus, the correct answer is option B. 

Which of the following present in the soil is most helpful to the growth of plants?

evs mud and stones soil - formation and profile soil-nature soil profile

  1. Humus

  2. Sand

  3. Clay

  4. Small porous rocks

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Correct Option: A
Explanation:

Humus is a type of organic material. It is present inside the soil in the form of a dark-coloured substance. Humus is formed by breaking down of plant litter that includes dried and fallen leaves, branches twigs etc. along with dead bodies of animals and insects. Over a period of time, all these decompose and cause break down of their complex substances into simple ones. It contains some of the important chemicals required for the soil for its nutrient maintenance. 

So, we can say that humus provides nutrients to the soil. Apart from this, in its presence, air and water can percolate through the soil particles easily, increasing its efficiency.
So, option A "Humus" is the correct answer.