Tag: biology

Questions Related to biology

Inexhaustible and non-conventional source of energy is

biology water and air and their importance water management - case studies introduction to natural resources management of natural resources

  1. Solar radiations

  2. Wind power

  3. Sea tides

  4. All the above

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Correct Option: D

A renewable exhaustible natural resource is 

biology water and air and their importance water management - case studies introduction to natural resources management of natural resources

  1. Forest

  2. Coal

  3. Petroleum

  4. Minerals

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Correct Option: A
Explanation:

Natural resources occur naturally within environments, that exist relatively undistributed by humanity, in a natural form. A natural resource is often characterized by amounts of biodiversity and geodiversity existent in various ecosystems. Natural resources are derived from the environment. Biotic resources are obtained from the biosphere (living and organic material), such as forests and animals, and the materials, that can be obtained from them. Forests and wildlife are both renewable in the short term but non renewable once a point has been reached or to a point. Forests can be managed to some degree sustainable forestry cuts older trees, while planting new one to replace them, this works in some types of environments better than others.

Fragmentation, leaching and catabolism are some of the important steps of decomposition. Study the following statements [(i), (ii) and (iii) regarding these and select the correct option.
(i) Detritivores(e.g., earthworm) breakdown detritus into smaller particles.
(ii) Water soluble inorganic nutrients go down into soil horizon and get precipitated as unavailable salts.
(iii) Decomposes(e.g., bacteria and fungi) secrete digestive enzymes and degrade detritus into simpler inorganic substances.

biology properties of natural resources properties of soil soil pollution and its effects soil and soil pollution

  1. Leaching-(i), Fragmentation- (ii), Catabolism-(iii)

  2. Leaching-(ii), Fragmentation-(ii), Catabolism-(i)

  3. Leaching-(ii), Fragmentation-(i), Catabolism-(iii)

  4. Leaching-(ii), Fragmentation-(iii), Catabolism-(i)

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Correct Option: C
Explanation:
The process of decomposition can be categorized as fragmentation of detritus, leaching, and catabolism.
Fragmentation of detritus is the process that causes breakdown of detritus into smaller particles. It is primarily due to the action of detritus feeding invertebrates(detritivores, e.g., termites, earthworms, etc.,) The detritus gets pulverized when passing through the digestive tracts of animals. Due to fragmentation, the surface area of detritus particles is greatly increased.
The extracellular enzymes released by bacteria and fungi carry out catabolism, i.e., enzymatic conversion of the decomposing detritus to simpler and inorganic substances.
Leaching is the process by which dissolved nutrients are moved into lower layers of soil or groundwater to form unavailable salts.
So, the correct answer is 'Leaching-(ii), Fragmentation-(i), Catabolism-(iii)'.

Which of the following enhances soil fertility?

biology properties of natural resources properties of soil soil pollution and its effects soil and soil pollution

  1. Crop rotation

  2. Improved methods of agriculture

  3. Using new seed varieties

  4. Irrigation

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Correct Option: A

A soil is said to be fertile when 

biology properties of natural resources properties of soil soil pollution and its effects soil and soil pollution

  1. It is rich in organic matter

  2. It has capacity to hold water

  3. It has a capacity to hold nutrients

  4. It holds water and all essential nutrients in a definite proportion

  5. All of the above

Show answer
Correct Option: E
Explanation:

Fertile soil has the following characteristics: 

1. It is rich in nutrients necessary for basic plant nourishment. This includes nitrogen, phosphorus and potassium. It consists of adequate minerals such as boron, chlorine, cobalt, copper, iron, manganese, magnesium, molybdenum, sulphur and zinc. These minerals promote plant nutrition. 
2. It contains soil organic matter, that improves the structure of the soil. This enables the soil to retain more moisture. The soil pH is in the range 6.0 to 6.8. 
3. It has a good soil structure, which results in well-drained soil. 
4. It consists of a variety of microorganisms, that support plant growth. It often contains large amounts of topsoil.

Soil carried by gravity is

biology properties of natural resources properties of soil soil pollution and its effects soil and soil pollution

  1. Alluvial

  2. Eolian

  3. Colluvial

  4. Glacier

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Correct Option: C
Explanation:

Colluvial soil is made of materials of all sizes (from boulders to clay), that accumulate at the bottom of steep slopes and cliffs without the help of streams. 

Sheet wash during rain storms and gravity are responsible for depositing this type of soil. Wheat is the main crop grown in colluvial soil. When the velocity of running water decreases, the heaviest particles are deposited on a riverbed. The finest particles (gravel, silt, sand, and clay) are deposited at the mouth of the river, forming a delta made of alluvial soil. 
Eolian sediments are wind deposited materials that consist primarily of sand or silt-sized particles. Glaciers are made up of fallen snow that, over many years, compresses into large, thickened ice masses.

Soil fertility is determined by its ability to

biology properties of natural resources properties of soil soil pollution and its effects soil and soil pollution

  1. Decay organic matter

  2. Hold organic matter

  3. Retain nutrients

  4. Support life

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Correct Option: D
Explanation:

Soil fertility is the ability of the soil to supply essential plant nutrients and soil water in adequate amounts for plant growth and reproduction, thereby support life. Thus the correct answer is option D.

Alluvial soil is mostly found in which region

biology properties of natural resources properties of soil soil pollution and its effects soil and soil pollution

  1. Southern India

  2. Northern India

  3. Gangetic Jamuna Plains

  4. Eastern India

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Correct Option: C
Explanation:
Alluvial soil covers about 40 percent of land area of India. It is depositional soils that are transported and deposited by rivers and stream formed by deposition of fine sediments and silt by the rivers along their banks. Such soil is mostly found in the Great Northern Plains of the river Ganga. Thus the correct answer is option C.

A fertile soil is likely to have a pH value of

biology properties of natural resources properties of soil soil pollution and its effects soil and soil pollution

  1. 3.5-4

  2. 8.5-9

  3. 5.5-7

  4. 10.5-11

Show answer
Correct Option: C
Explanation:

Fertile soil contains sufficient minerals and nutrients needed for plant growth. Most minerals and nutrients are more soluble in slightly acidic soil than in neutral or slightly alkaline soils. The pH range of 5.5-7 is highly suitable for plant growth and hence such a soil is considered fertile. Thus the correct answer is option C.

The best soil for healthy and vigorous growth of most plants is

biology properties of natural resources properties of soil soil pollution and its effects soil and soil pollution

  1. Sandy soil

  2. Loam soil

  3. Clay soil

  4. None of these

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Correct Option: B
Explanation:

Loam soil is a soil that has a good combination of minerals, rock, sand, silt water and organic matter. The soil contains microorganisms, insects and worms that replenish soil fertility. Because of this good composition, it is the healthiest type of soil. Thus the correct answer is option B.