Tag: soil : our life

Quizzes (12) Questions (114)

Questions Related to soil : our life

Multiple choice biology soil : our life soil properties soil - properties basics of soil pollution

pH of a normal fertile soil is

  1. 4 - 5

  2. 6 - 7

  3. 7.2 - 9.0

  4. None of the above
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Soil pH is in the range of 6 to 7 for most plants but some prefer acid or alkaline conditions. At this pH soil organic matter and structure is very good. A lot of micro-organisms, that support plant growth can live in the soil at this pH.

Multiple choice biology soil : our life soil properties soil - properties basics of soil pollution

The soil near the surface is usually darker, than the soil about one meter down. This is because the topsoil is 

  1. Young and wet

  2. Richer in organic matter

  3. Richer in Ca and Mg

  4. Dry
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Plants and animals aid in the development of a soil through the addition of organic matter. Fungi and bacteria decompose this organic matter into a semi-soluble chemical substance, known as humus. Larger soil organisms, like earthworms, beetles, and termites, vertically redistribute this humus within the mineral matter found beneath the surface of a soil. Humus is the biochemical substance, that makes the upper layers of the soil become dark. It is coloured as dark brown to black. 

Multiple choice biology soil : our life soil properties soil - properties basics of soil pollution

Solubility and availability of plant nutrients are related to

  1. Soil pH

  2. Soil porosity

  3. Soil temperature

  4. Soil colour
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Soil pH is important because it influences several soil factors affecting plant growth, such as :

(1) soil bacteria, 
(2) nutrient leaching, 
(3) nutrient availability, 
(4) toxic elements, and 
(5) soil structure. 
Bacterial activity that releases nitrogen from organic matter and certain fertilizers is particularly affected by soil pH, because bacteria operate best in the pH range of 5.5 to 7.0. Plant nutrients leach out of soils with a pH below 5.0 much more rapidly than from soils with values between 5.0 and 7.5. Plant nutrients are generally most available to plants in the pH range 5.5 to 6.5.

Multiple choice biology soil : our life soil properties soil - properties basics of soil pollution

Which is best for plant growth?

  1. Loamy soil

  2. Silt

  3. Sandy soil

  4. Clay soil
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Loam is considered ideal for gardening and agricultural uses, because it retains nutrients well and retains water, while still allowing excess water to drain away. 

Silt is granular material of a size between sand and clay, whose mineral origin is quartz and feldspar. 
Sandy soils are granular soils, that contain small rock and mineral particles. 
Clay is a fine-grained natural rock or soil material, that combines one or more clay minerals with traces of metal oxides and organic matter.

Multiple choice biology soil : our life soil properties soil - properties basics of soil pollution

Soil hold water in it, it is called as 

  1. Soil water

  2. Ground water

  3. Soil moisture

  4. None of the above
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Soil water is often referred to as soil moisture. Soil is the amount of water present in the interparticle spaces in the soil and is available to plants. When soil moisture gets depleted, enough water is not available for plants. So they have to apply more pressure in obtaining water from around the soil particles. 

So, option C "Soil Moisture" is the correct option.

Multiple choice biology soil : our life soil properties soil - properties basics of soil pollution

A fertile soil is likely to have a pH value of

  1. 3-4

  2. 8-9

  3. 6-7

  4. 10-11
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Soil pH is important because it influences several soil factors affecting plant growth, such as (1) soil bacteria, (2) nutrient leaching, (3) nutrient availability, (4) toxic elements and (5) soil structure. Bacterial activity that releases nitrogen from organic matter and certain fertilizers is particularly affected by soil pH, because bacteria operate best in the pH range of 5.5 to 7.0. Plant nutrients leach out of soils with a pH below 5.0 much more rapidly than from soils with values between 5.0 and 7.5. Plant nutrients are generally most available to plants in the pH range 5.5 to 6.5. For most plants, the optimum pH range is from 5.5 to 7.0.

Therefore, the correct answer is option D. 

Multiple choice biology soil : our life soil properties soil - properties basics of soil pollution

The size of clay particle is less than

  1. 0.02 mm

  2. 0.002 mm

  3. 0.2 mm

  4. 2.0 mm
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Soil particles vary greatly in size, and soil scientists classify soil particles into sand, silt, and clay. Starting with the finest, clay particles are smaller than 0.002 mm in diameter. Some clay particles are so small, that ordinary microscopes do not show them. Silt particles are from 0.002 to 0.05 mm in diameter. Sand ranges from 0.05 to 2.0 mm. Particles larger than 2.0 mm are called as gravel or stones. Most soils contain a mixture of sand, silt and clay in different proportions.

Multiple choice biology soil : our life soil properties soil - properties basics of soil pollution

Which is the characteristic featue of a physiologically dry soil ?

  1. Light available to plants is not sufficient

  2. There is plenty of water in the soil

  3. Concentration of salts is very high in the soil

  4. Soil is stony
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

A physiologically dry soil is a soil in which the concentration of oxygen is very less and that of salt is very high. Normal plants cannot grow in such soil and only halophytes are found in them. The Sunderbans in West Bengal are rich in physiologically dry soil. Thus the correct answer is option C.

Multiple choice biology soil : our life soil properties soil - properties basics of soil pollution

Formula of rate of percolation is

  1. Percolation rate (mL/min) = $\displaystyle \frac {amount\,of\,water(mL)}{percolation\,time(min)}$

  2. Percolation rate (mL/min) = $\displaystyle \frac {percolation\,time(min)}{amount\,of\,water(mL)}$

  3. Both A and B

  4. None of these
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

  • The process of absorption of water by the soil is called percolation. It is different for different soil types and depends upon the soil compositions. It is calculated by the formula i.e., percolation rate = amount of water/percolation time.

 Thus the correct answer is option A.

Multiple choice biology soil : our life soil properties soil - properties basics of soil pollution

Soil that is rich in soluble salts is

  1. Laterite

  2. Halomorphic

  3. Calcimorphic

  4. None of these
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

In the steppes and deserts, evaporation greatly exceeds precipitation. The products of rock weathering are brought by intermittent flowing streams during a flood and left behind on the basin floor. This soil has clay, silt and sand are the dissolved mineral salts and is called halomorphic soil. Thus the correct answer is option B.