Tag: soil-nature

Questions Related to soil-nature

When a small amount of garden soil is put into a glass jar containing water, stirred and allowed to stand for two hours, the layers from top to bottom would be

  1. Debris, water, sand and clay

  2. Humus, water, clay and sand

  3. Debris, clay, gravel and sand

  4. Humus, clay, gravel and sand


Correct Option: B
Explanation:

Soil is comprised of air spaces and organic matter, but mostly mineral particles. There are three kinds of soil minerals, sand, silt and clay. The relative percentage of each of these particles in the soil determines its texture. Sand has the largest soil particles (0.4- to 0.01-inch diameter) and the largest pores between particles. Silt soil particle size is between clay and sand (0.01- to 0.0001-inch diameter). The characteristics of silty soil are similar to those of clay, but are moderated by its larger particle size. Clay soil has the smallest soil particles (less than 0.0001-inch diameter) and the least amount of water and air spaces between particles. Humus is dark, organic material that forms in soil when plant and animal matter decays. The thick brown or black substance that remains after most of the organic litter has decomposed is called as humus. Hence, humus settles at the topmost and sand the lowermost since, its size is maximum.

Match the following.

Column I Column II
I. Sandy soil A. 85% sand + 15% clay or silt
II. Loam soil B. 70% sand + 30% clay or silt
III. Silt C. 50% sand + 50% clay or silt or both
  D. 90% silt + 10% sand
  1. I-A, II-D, lll-C

  2. I- A, II- B, lll- D

  3. I- A, II- D, lll- B

  4. I- A, II- B, lll- C

  5. I- A, II- C, lll- D


Correct Option: E
Explanation:

Sand can refer to a textural class of soil or soil type; i.e., a soil containing more than 85% sand-sized particles (by mass) and 15% clay.

A loamy soil is one that combines sand and clay particles in relatively equal amounts. Loamy soil is ideal for most garden plants because it holds plenty of moisture but also drains well so that sufficient air can reach the roots. Loam is soil composed mostly of sand and silt, and a smaller amount of clay (about 70%-30% concentration, respectively). The soil can be called as silt if its silt content is greater than 90 percent.

Which of the following characteristics is not a function of humus in soil?

  1. Provides nutrients

  2. Raises pH

  3. Retains moisture

  4. Humus does all of the above in soil


Correct Option: B
Explanation:

Explanation: Humus is the end product of broken down (decayed) organic matter. Humus is an essential component of healthy soils that has many great benefits.

Mineral nodules present in ocean which can meet shortage of important soil nutrient are

  1. Manganese nodules

  2. Phosphorite nodules

  3. Magnesium nodules

  4. All of the above


Correct Option: B
Explanation:
  • Phosphorite rocks are spherical concentrations that are randomly distributed along the floor of continental shelves. It contains high amounts of phosphate minerals. 
  • The size of Phosphorite nodules can range up to several tens of centimetres.
  • Hence Mineral nodules present in the ocean which can meet the shortage of important soil nutrient are Phosphorite nodules.
  • So, the correct answer is 'Phosphorite nodules'.

I. Temperature
II. Humidity
III. Vegetation 
The abiotic factors of ecosystem include

  1. I only

  2. II only

  3. III only

  4. I and II only

  5. I, II and III


Correct Option: D
Explanation:

Biotic factors of an ecosystem include all plant and animal species present in there. The abiotic factors include a physical environment in which they can survive. It includes light, temperature, humidity and other climatic condition as well as physical factors like soil. Thus, the correct answer is D. 

Pedology is the science of

  1. Rocks

  2. Diseases

  3. Soil

  4. Pollution


Correct Option: C
Explanation:

Pedology is the study of soils in their natural environment. It is one of the two branches of soil.

Edaphology is the relationship between

  1. Plant and biosphere

  2. Animal and ecosystem

  3. Soil and living organisms

  4. Soil and biosphere


Correct Option: C

The part of the biosphere which contains soil is known as 

  1. Pedosphere

  2. Lithosphere

  3. Hygrosphere

  4. Toposphere


Correct Option: A
Explanation:
  • Pedosphere is an outer layer of earth that contains soil.
  • Lithosphere includes the brittle upper portion of the mantle, crust and Mantles are made of rock or ices. 
  • Hydrosphere contains all the waters on the earth's surface, such as lakes and seas.
  • Troposphere is the lowest layer of the atmosphere, closest to the earth's surface. so option A is a correct answer.

In a .......... ecosystem, the producers are mostly herbaceous or woody plants.

  1. Terrestrial

  2. Aquatic

  3. Desert

  4. None of these


Correct Option: A
Explanation:

Herbaceous plants are plants with very flexible stems. Woody plants include trees and shrubs. These are the plants present in the terrestrial ecosystem. They convert solar energy into chemical energy through photosynthesis in which carbon dioxide and water are used in presence of sunlight to synthesize nutrients such carbohydrates in the form of glucose and release oxygen into the atmosphere. Since plants form the base of the terrestrial ecosystem they are the producers.

Environment consists of

  1. land, air, water

  2. light, temperature and rainfall

  3. plants, animals and microbes

  4. All the above


Correct Option: D
Explanation:
The environment consists of two major components:
  • Abiotic components: These are non-living components of the environment and consist of two things, materials and energy (that may be light or chemical energy). Materials include land, air, water, minerals, salts, atmospheric gases, rainfall, temperature etc.
  • Biotic components: These are living components of the environment and divided into autotrophic and heterotrophic components. An autotrophic component is the producers or green plants while heterotrophic component includes consumers (primary, secondary and tertiary consumers) and decomposers (microbes).
Hence, all the given options are correct.
So, the correct answer is 'All the above'.