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 81–90 of 168 questions
RAS PrelimsHealth, Environment and Agriculture · Environmental and Ecological Changes and Impact Assessment
Q81. Match List I with List II regarding ozone protection agreements:
International Protocol/Amendment
Key Focus
A. Vienna Convention
i. Phase-down of Hydrofluorocarbons (HFCs)
B. Montreal Protocol
ii. Framework for protection of the ozone layer
C. Kigali Amendment
iii. Phase-out of ozone-depleting substances (ODS)
Explanation
International efforts to protect the atmosphere have evolved through several key agreements. The initial framework established a commitment to cooperation and research. This was followed by a binding treaty to phase out the production of substances that directly destroy ozone molecules. More recently, an amendment was added to target other chemicals that, while safe for ozone, contribute significantly to the global warming problem.
RAS PrelimsHealth, Environment and Agriculture · Environmental and Ecological Changes and Impact Assessment
Q82. Why was the Kigali Amendment to the Montreal Protocol deemed necessary?
Explanation
While the original agreement successfully addressed chemicals that were destroying the ozone layer, their replacements turned out to be extremely potent greenhouse gases. To prevent these substitutes from contributing to rapid global warming, an international amendment was adopted. This new regulation requires a gradual reduction in the use of these heat-trapping substances, helping to protect both the ozone layer and the global climate system.
RAS PrelimsHealth, Environment and Agriculture · Environmental and Ecological Changes and Impact Assessment
Q83. Polar Stratospheric Clouds (PSCs) play a crucial role in ozone depletion over Antarctica by:
Explanation
During the dark polar winter, the temperature in the upper atmosphere can drop low enough for clouds to form in a region that is usually very dry. These clouds provide a solid surface where chemical reactions occur between stable reservoir molecules. When the sun returns in the spring, these reactions release highly reactive forms of chlorine, which then rapidly destroy ozone in a catastrophic cycle.
RAS PrelimsHealth, Environment and Agriculture · Environmental and Ecological Changes and Impact Assessment
Q84. The thickness of the ozone layer is measured in which of the following units?
Explanation
Scientists use a specific unit to represent the total amount of ozone in a vertical column of air above a given location. It is defined as the thickness that the ozone would have if it were compressed into a pure layer at standard temperature and pressure. This measure allows for easy comparison of ozone levels across the globe and helps track the recovery of the protective layer.
RAS PrelimsHealth, Environment and Agriculture · Environmental and Ecological Changes and Impact Assessment
Q85. Which of the following is an expected health consequence of a significantly depleted ozone layer?
Explanation
A significant decrease in the concentration of ozone in the upper atmosphere allows more high-energy radiation to reach the Earth’s surface. This increased exposure is directly linked to several serious human health issues. Most notably, it leads to higher incidences of DNA damage in skin cells and clouding of the lens in the eye. These conditions can result in chronic illness and loss of vision over time.
RAS PrelimsHealth, Environment and Agriculture · Environmental and Ecological Changes and Impact Assessment
Q86. Desertification is formally defined by the UNCCD as land degradation in which specific areas?
Explanation
Land degradation in specific climate zones is a major global environmental challenge. This process occurs in regions where the amount of water lost through evaporation and plant usage exceeds the amount of rainfall received. These dry areas are particularly vulnerable to over-exploitation and shifting weather patterns. When the soil in these zones loses its productivity and biological potential, it is formally described as a type of desertification.
RAS PrelimsHealth, Environment and Agriculture · Environmental and Ecological Changes and Impact Assessment
Q87. Which anthropogenic activity is the leading cause of desertification globally?
Explanation
Several human activities contribute to the loss of productive land in dry regions. The most significant factor worldwide is the pressure placed on vegetation by large numbers of domestic animals. When livestock eat more plants than can naturally regrow, the soil is left exposed to wind and water erosion. This disruption of the natural plant cover is the primary driver of the degradation seen in many arid lands.
RAS PrelimsHealth, Environment and Agriculture · Environmental and Ecological Changes and Impact Assessment
Q88. The "Great Green Wall" is a monumental project aimed at combating desertification in which region?
Explanation
An ambitious project aims to restore millions of hectares of degraded land by planting a massive belt of trees and vegetation across a wide geographical area. This initiative is focused on a transition zone south of a major desert, where environmental conditions are increasingly harsh. By creating a living barrier, the project helps to improve soil health, provide local resources, and combat the southward expansion of drylands.
RAS PrelimsHealth, Environment and Agriculture · Environmental and Ecological Changes and Impact Assessment
Q89. What is a common soil consequence of poor irrigation practices in arid areas that contributes to desertification?
Explanation
In arid environments, using too much water for farming can have unintended negative effects on the soil. When water is added to the ground, it can cause the water table to rise, bringing dissolved minerals to the surface. As the water eventually evaporates in the heat, these minerals are left behind. The resulting accumulation of salt makes the ground toxic to most crops, accelerating the degradation process.
RAS PrelimsHealth, Environment and Agriculture · Environmental and Ecological Changes and Impact Assessment
Q90. Which UN convention specifically addresses the issue of desertification?
Explanation
A specific international agreement was established to address the problem of land degradation and the impacts of drought, particularly in vulnerable regions. This treaty provides a framework for cooperation and action to restore productive soil and manage land sustainably. It emphasizes the importance of community involvement and scientific knowledge in creating long-term solutions for people living in the world’s most affected dryland areas.
Answer key for these questions
Q
Correct answer
81
(c) A-ii, B-iii, C-i
82
(a) To target HFCs, which are potent GHGs
83
(d) Providing surfaces for chlorine release
84
(b) Dobson Units (DU)
85
(c) Higher rates of skin cancer and cataracts
86
(a) Arid, semi-arid, and dry sub-humid areas
87
(b) Overgrazing by livestock
88
(b) The Sahel region, Africa
89
(a) Soil salinization
90
(c) UNCCD
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.
