UGC NTA NET/JRF Exam, Environmental Sciences, September-2022

Total Questions: 100

51. Arrange the following elements of image interpretations in order of increasing complexity.

(a) Location
(b) Tone
(c) Situation
(d) Pattern
(e) Texture
Choose the correct answer from the options given below:

Correct Answer: B. (a), (b), (e), (d), (c)
Solution:

Aerial photographic and satellite image interpretation, or just image interpretation when in context, is the act of examining photographic images, particularly airborne and spaceborne, for the purpose of identifying objects and judging their significance.

The elements of image interpretation include location, tone and colour, size, shape, textue, pattern, shadow, height and depth, volume, slope, aspect, site, situation, and association.
Tone or Colour: Relates to the spectral reflectance characteristics of objects.
Size: Measure of surface dimensions of objects, including height, length-width, slope.
Shape: Describes the form or configuration of an object.
Texture: Frequency of tonal or colour change which determines apparent roughness vs. smoothness of an image region; depends on angle of illumination and surface characteristics.
Pattern: Spatial arrangement of individual objects into distinctive, recurring forms. Shadows: May reveal details about size and shape not apparent from overhead view.
Site: Location of object in relation to its geographic or topographic setting.
Association: Occurrence of certain features in relation to others.

52. Basalts are composed of the following minerals.

(a) Olivine
(b) Pyroxene
(c) Quartz
(d) Orthoclase
(e) Plagioclase
Choose the correct answer from the options given below:

Correct Answer: C. (a), (b) and (e) only
Solution:

Basalts are common aphanitic igneous extrusive (volcanic) rocks. Basalts are composed of minute grains of plagioclase feldspar (generally labradorite), pyroxene, olivine, biotite, hornblende and <20% quartz.

Basalts are formed by the rapid cooling of basaltic lava, equivalent to gabbro-norite magma, from interior of the crust and exposed at or very close to the surface of Earth.

These basalt flows are quite thick and extensive, in which gas cavities are almost absent. In case of thin and irregular lava flows, gas cavities are formed on the rock surface. The rock is called "vesicular" basalt when the gas cavities are empty.

53. Arrange the following minerals with increasing order of stability for weathering.

(a) Illite
(b) Olivine
(c) Calcite
(d) Ca rich feldspar
(e) Na rich feldspar
Choose the correct answer from the options given below:

Correct Answer: D. (c), (b), (d), (e), (a)
Solution:

Chemical weathering results from chemical changes to minerals that become unstable when they are exposed to surface conditions.

The kinds of changes that take place are highly specific to the mineral and the environmental conditions.

Arrangement as per increasing order of stability for weathering : Calcite, Olivine, Ca rich feldspar, Na rich feldspar, Illite.

54. Choose the correct sequence of filtration processes used for sequential removal of particles from coarser (1 µm) to finer grain sizes.

Correct Answer: B. (a), (b), (c), (d)
Solution:

Filtration is a process of removing particulate matter from water by forcing the water through a porous media. This porous media can be natural, in the case of sand, gravel and clay, or it can be a membrane wall made of various materials.

The size of materials that can be removed during filtration depends upon the size of the pores of the filter.

The chart below summarizes the various separation processes relative to common materials that would be filtered out through each process. Particle filtration refers to conventional media filtration, while the other types are membrane filtrations.

55. In waste pollution prevention hierarchy, arrange following from least preferred to most preferred.

(a) Waste Concentration
(b) Waste Separation
(c) Waste treatment
(d) Recycling or Reuse
(e) Landfill
Choose the correct answer from the options given below:

Correct Answer: B. (e), (c), (а), (b), (d)
Solution:

Waste is an inevitable by-product of human life. Virtually every human activity generates some type of material side effect or by-product.

When the materials that constitute these by-products are not useful or have been degraded such that they no longer fulfill their original or other obvious useful purpose, they are classified as a waste material.
Waste hierarchy. Ordered by most prefereble: avoid and reduce; reuse; recycle; recover energy; treat; dispose of waste.

56. Given below are two statements.

StatementI: Key to nitrogen cycle is nitrogen fixing bacteria, which has ability to fix N₂ or combine gases N₂ with hydrogen to form NH₃.

Statement II: Nitrogen cycle includes fixation of molecular N₂ to ammonia to nitrite to nitrate only. It does not include denitrification process.
In light of the above statements, choose the correct answer from the options given below:

Correct Answer: C. Statement I is true, but Statement II is false
Solution:

Biological nitrogen fixation (BNF), discovered by Beijerinck in 1901 (Beijerinck 1901), is carried out by a specialized group of prokaryotes. These organisms utilize the enzyme nitrogenase to catalyze the conversion of atmospheric nitrogen (N₂) to ammonia (NH₂). Hence Statement I is true.

Nitrification is the process that converts ammonia to nitrite and then to nitrate and is another important step in the global nitrogen cycle. Most nitrification occurs aerobically and is carried out exclusively by prokaryotes
1. NH₃ + O₂ + 2e⁻ → NH₂OH + H₂O
2. NH₂OH + H₂O →NO₃ + 5H⁺ + 4e⁻
Hence, Statement II is not correct.

57. Given below are two statements.

Statement I : Halons used as fire extinguishers are bromine containing hydrogen free substances and are involved in catalytic destruction of ozone in Stratosphere.

Statement II : In order to protect ozone layer in stratosphere, use of CFC was globally replaced by HCFCs, HFC's followed by Halons after Kyoto protocol.

In light of the above statements, choose the correct answer from the options given below:

Correct Answer: C. Statement I is true, but Statement II is false
Solution:

Bromine-containing halons also significantly contribute to the depletion of stratospheric ozone when these halons photodissociate and release bromine atoms. Just as a chlorine atom destroys ozone, a bromine atom can also destroy ozone:
Br + O₃ → BrO + O₂.
The preceding reactions occur throughout the stratosphere and are responsible for depletion of ozone on a global scale.
Only Statement I is correct

The Montreal Protocol, finalized in 1987, is a global agreement to protect the stratospheric ozone layer by phasing out the production and consumption of ozone-depleting substances (ODS).

The Montreal Protocol has proven to be innovative and successful, and is the first treaty to achieve universal ratification by all countries in the world.

58. Given below are two statements.

Statement I: Yellow carotenes and paleyellow xanthophyll pigments are with strong reflectance primarily in the blue wavelength regime of Electromagnetic Radiation (EMR).
Statement II: There are many other pigments present in the palisade mesophyll cells that are usually marked by the abundance of chlorophyll pigments.

In light of the above statements, choose the correct answer from the options given below:

Correct Answer: D. Statement I is false, but Statement II is true
Solution:

Here, Statement I is false, but Statement II is true.
There are many other pigments present in the palisade mesophyll cells that are usually marked by the abundance of chlorophyll pigments.

59. Given below are two statements.

Statement I: Ecotypes are discrete entity because they have clear differences in morphology, physiology and phenology in relation to particular environmental conditions.
Statement II : The environmentally induced variations in ecotypes are not heritable and do not have adaptive value to a particular habitat
In light of the above statements, choose the correct answer from the options given below:

Correct Answer: C. Statement I is true but Statement II is false
Solution:

On the basis of classical studies of Turesson (1922) and Clausen et al. (1940), the ecotypes are defined as "mosaic of populations in which environmentally induced variations in morphology and physiology are genetically fixed and are heritable". Some important attributes of ecotypes are as follows:

1. Ecotypes are discrete entity because they have clear differences in morphology, physiology and phenology in relation to particular environmental conditions.

2. The ecotypes are potentially interfertile with other ecotypes of the same species. But ecotypes are prevented from interbreeding due to ecological barriers.

60. Given below are two statements.

StatementI: A confined aquifer is an aquifer which is confined between impervious beds such as aquicludes or aquifuges.

Statement II: Recharge of this aquifer takes place only in the area where it is exposed at the ground surface.
In light of the above statements, choose the correct answer from the options given below:

Correct Answer: A. Both Statement I and Statement II are true
Solution:

Aquifers are classified as Unconfined aquifers and Confined aquifers on the basis of their occurrence and field situation. An unconfined aquifer (also known as water table aquifer) is one in which a free water surface, i.e., a water table exists. Only the saturated zone of this aquifer is of importance in groundwater studies.

A confined aquifer, also known as artesian aquifer, is an aquifer which is confined between two impervious beds such as aquicludes or aquifuges. Recharge of this aquifer takes place only in the area where it is exposed at the ground surface.

The water in the confined aquifer will be under pressure and hence the piezometric level will be much higher than the top level of the aquifer.