Environmental and Ecological Changes and Impact Assessment: RAS Prelims MCQs
168 RAS Prelims MCQs on environmental and ecological changes and impact assessment cover ecosystem concepts, pollution, climate and environmental law. Ecotones, decomposers, primary productivity, secondary pollutants, the greenhouse effect, the EIA Notification 2006, the Environment (Protection) Act 1986 and the Aravalli mining ban are asked as definitions, laws and statements.
Practice questions based on the RPSC RAS Prelims syllabus. They follow the exam pattern but are not past-paper questions.
Showing 91–100 of 168 questions
RAS PrelimsHealth, Environment and Agriculture · Environmental and Ecological Changes and Impact Assessment
Q91. Match List I with List II regarding mechanisms against desertification:
Control Measure
Mechanism against Desertification
A. Shelterbelts
i. Prevents soil erosion on steep slopes
B. Sand dune stabilization
ii. Rows of trees planted to reduce wind speed
C. Crop rotation
iii. Planting grasses to bind loose sand
D. Terracing
iv. Maintains soil fertility and structure over seasons
Explanation
Several techniques are used to prevent and reverse the degradation of drylands. Planting rows of trees helps to slow down the wind and protect the soil from being blown away. On hillsides, building steps prevents water from washing away the topsoil. Using different crops in a sequence helps maintain nutrients, while specific methods are used to stop the movement of loose sand and stabilize the ground.
RAS PrelimsHealth, Environment and Agriculture · Environmental and Ecological Changes and Impact Assessment
Q92. How does desertification impact the global climate?
Explanation
The loss of vegetation and soil health in dry regions has significant implications for the global atmosphere. Healthy soil and plants act as reservoirs for carbon, keeping it out of the air. When land becomes degraded, this stored carbon is released, primarily as a heat-trapping gas. This contribution to the greenhouse effect helps drive global warming, which can then create even more severe droughts in a dangerous cycle.
RAS PrelimsHealth, Environment and Agriculture · Environmental and Ecological Changes and Impact Assessment
Q93. Which of the following states in India has the highest proportion of its geographical area under desertification/land degradation?
Explanation
Large areas of land in India are facing the threat of degradation due to both natural factors and human activities. The impact is most severe in a northern state that contains a vast arid region. Because of its climate and the high demand for limited resources, more than half of the land in this state is considered to be affected by the processes that lead to the loss of productivity.
RAS PrelimsHealth, Environment and Agriculture · Environmental and Ecological Changes and Impact Assessment
Q94. Identify the incorrect statement regarding desertification.
Explanation
Desertification is a complex process of land degradation driven by climate change and human actions. It leads to the loss of plant life and a decrease in the land’s ability to produce food. However, it is important to understand that this phenomenon is not simply about the movement of existing deserts. Instead, it involves the gradual decline of productivity in various dryland areas that were previously fertile.
RAS PrelimsHealth, Environment and Agriculture · Environmental and Ecological Changes and Impact Assessment
Q95. The concept of "Land Degradation Neutrality" (LDN) implies:
Explanation
A key global goal is to ensure that the total amount and quality of healthy land resources remain stable or increase over time. This concept focuses on balancing any new degradation with the restoration of land that has already been damaged. By maintaining the natural potential of the soil, societies can ensure food security and protect the essential services that ecosystems provide to all living beings on the planet.
RAS PrelimsHealth, Environment and Agriculture · Environmental and Ecological Changes and Impact Assessment
Q96. Regarding deforestation, consider the following statements: I. It alters local microclimates and reduces rainfall. II. It is a major driver of biodiversity loss. III. It decreases the concentration of carbon dioxide in the atmosphere. IV. It exacerbates soil erosion and flooding. V. Expansion of commercial agriculture is a leading cause. Which of the above statement(s) is/are correct?
Explanation
The large-scale removal of trees has profound effects on the environment at both local and global scales. It disrupts weather patterns, increases the risk of floods, and is a primary reason for the extinction of many species. Furthermore, instead of lowering the amount of carbon dioxide in the air, the loss of forests actually increases it, as the stored carbon is released during the clearing process.
RAS PrelimsHealth, Environment and Agriculture · Environmental and Ecological Changes and Impact Assessment
Q97. "Slash-and-burn" agriculture, which contributes heavily to deforestation in tropical areas, is also known in India as:
Explanation
A traditional farming method involves clearing a patch of forest by cutting down trees and burning the remaining vegetation to fertilize the soil. After a few years of growing crops, the land is left to recover while the farmers move to a new area. While this practice worked when populations were small, it now contributes significantly to the permanent loss of forests and biodiversity in many regions.
RAS PrelimsHealth, Environment and Agriculture · Environmental and Ecological Changes and Impact Assessment
Q98. The REDD+ initiative is a global effort primarily aimed at:
Explanation
An international mechanism was created to encourage developing nations to protect their forests as a way to combat global warming. This program provides financial incentives for countries to reduce the rates of tree clearing and degradation. By valuing the carbon stored in standing forests, the initiative aims to make conservation more economically attractive than activities that lead to the permanent loss of essential woodland ecosystems.
RAS PrelimsHealth, Environment and Agriculture · Environmental and Ecological Changes and Impact Assessment
Q99. Deforestation directly affects the water cycle by:
Explanation
Forests play a vital role in moving water from the ground back into the air through their leaves. When trees are removed, this natural process is significantly reduced, leading to drier local conditions and a decrease in rainfall. Furthermore, the absence of a tree canopy and root systems means that less water is absorbed by the soil, which increases the speed of runoff and the frequency of floods.
RAS PrelimsHealth, Environment and Agriculture · Environmental and Ecological Changes and Impact Assessment
Q100. The term ‘Afforestation’ refers to:
Explanation
Establishing a new forest in an area where trees have not grown for a long period is a key strategy for environmental restoration. This human activity involves planting a variety of species on land that was previously used for other purposes, such as agriculture or mining. By creating these new woodland areas, it is possible to increase carbon storage, protect the soil from erosion, and provide new habitats for wildlife.
Answer key for these questions
Q
Correct answer
91
(d) A-ii, B-iii, C-iv, D-i
92
(c) It releases stored carbon from soil
93
(b) Rajasthan
94
(d) It refers primarily to the expansion of existing deserts into non-desert areas.
95
(a) Maintaining healthy land resources
96
(b) I, II, IV and V
97
(a) Jhum cultivation
98
(d) Reducing emissions from deforestation
99
(b) Reducing precipitation via evapotranspiration
100
(c) Planting trees where none existed recently
Key facts from Environmental and Ecological Changes and Impact Assessment
An ecosystem is made of interacting organisms and their physical environment; an ecotone is a zone of transition between ecosystems.
Saprotrophs convert complex organic matter into simple substances; gross primary productivity is the rate at which producers create organic matter.
Plants release water vapour through transpiration.
Ground-level ozone is a secondary pollutant; CO, SO₂ and PM10 are primary pollutants.
The greenhouse effect is the trapping of heat by atmospheric gases.
Category B2 projects are exempt from public consultation under the EIA Notification 2006; the Supreme Court banned mining in the Aravalli range in Haryana and Rajasthan.
Frequently asked questions
How many RAS Prelims practice MCQs are there on Environmental and Ecological Changes and Impact Assessment?
This page has 168 practice MCQs on Environmental and Ecological Changes and Impact Assessment (Health, Environment and Agriculture). Each has the correct answer, and most have an explanation.
What is a secondary pollutant?
A pollutant that is not emitted directly but forms in the air from primary pollutants. Ground-level ozone is the standard example, formed when nitrogen oxides and volatile organic compounds react in sunlight.
What is an ecotone?
A zone of transition between two different ecosystems, such as the area between a forest and a grassland. It often has more species than either neighbour because it has species of both.
Which projects are exempt from public consultation under EIA 2006?
Category B2 projects, which have less environmental impact. Category A and B1 projects need public consultation as part of the clearance process, which is the main way local people are heard.
