Conservation of Plants & Animals- 1 - UPSC Free MCQ Test with solutions

Carbon dioxide plays a crucial role in photosynthesis, which is the process by which plants convert light energy into chemical energy. The correct answer is B. It is absorbed by plants, as plants take in carbon dioxide from the atmosphere through small openings in their leaves called stomata.

Explanation of Incorrect Options

• A. It is a waste product - This is incorrect because carbon dioxide is not a waste product; rather, it is a vital reactant in the photosynthesis process.
• C. It is not involved in photosynthesis - This statement is false as carbon dioxide is essential for photosynthesis, being one of the key inputs needed to produce glucose and oxygen.
• D. It is released by plants - This option is misleading. While plants do release oxygen as a byproduct of photosynthesis, they do not release carbon dioxide; they absorb it.

Explanation of Correct Answer

The correct answer is Reduces fertility. Deforestation leads to the removal of trees, which play a crucial role in maintaining soil health. The absence of vegetation results in increased soil erosion, loss of nutrients, and a decline in the organic matter that contributes to soil fertility.

Explanation of Incorrect Options

• Increases fertility: This option is incorrect because deforestation typically leads to soil degradation rather than an increase in fertility.
• Stabilizes fertility: This option is also incorrect as the removal of trees disrupts the natural balance of the ecosystem, leading to a decline in soil quality.
• Has no effect on fertility: This option is misleading; deforestation significantly impacts soil fertility by increasing erosion and reducing nutrient levels.

The correct answer is Red Data Book. This book is an important source that maintains a record of all endangered species of plants and animals. It is compiled and updated by various organisations worldwide, including those in India, which also maintains its own version of the Red Data Book.

Explanation of Incorrect Options

• Green Data Book: This option does not exist as a recognised publication for endangered species.
• Blue Data Book: Similar to the Green Data Book, this is not a standard reference for endangered species.
• Yellow Data Book: This option is also not a recognised title for a publication regarding endangered species.

Explanation of Correct Answer

The correct answer is Floods. Soil erosion removes the top layer of soil, which is crucial for water absorption. When heavy rains occur, the lack of soil to absorb the water can lead to an increase in surface runoff, causing floods.

Explanation of Incorrect Options

• Water logging: This occurs when there is excessive water accumulation in the soil, often due to poor drainage, not directly as a result of soil erosion.
• Water scarcity: While soil erosion can affect water retention in the long term, it does not directly lead to immediate water scarcity.
• Air pollution: Soil erosion does not directly cause air pollution; rather, it can contribute to environmental degradation, but the link is indirect.

Deforestation significantly impacts the movement of water from the soil surface into the ground, known as the infiltration rate. The correct answer is Reduced infiltration rate because:

Explanation of Correct Answer

When trees are removed, the soil structure is altered, leading to increased soil erosion and a decrease in the soil's ability to retain moisture. This results in a lower infiltration rate, meaning less water is absorbed into the ground.

Explanation of Incorrect Options

• Increased infiltration rate: This option is incorrect because deforestation typically leads to soil compaction and erosion, which reduces the infiltration rate.
• No change in infiltration rate: This option is also incorrect as the removal of trees and vegetation directly affects the soil's physical properties, leading to changes in infiltration.
• Enhanced water retention: This option is incorrect because deforestation decreases the soil's capacity to retain water due to the loss of vegetation that normally helps to hold moisture in the soil.

Explanation of Correct Answer

The correct answer is forest fires. Forest fires are a natural cause of deforestation, as they can lead to the destruction of large areas of forest, making the land unusable for other purposes.

Explanation of Incorrect Options

• Blizzards: While blizzards can cause damage to trees, they do not typically lead to widespread deforestation.
• Earthquakes: Earthquakes can cause localized damage to forests but are not a common cause of deforestation on a large scale.
• None of these: This option is incorrect because forest fires are indeed a natural cause of deforestation.

Explanation of Correct Answer

The correct answer is A. Trees in forests are primarily cut for various human activities, including:

• Procuring land for cultivation
• Building houses and factories
• Making furniture

These activities directly relate to the need for land and resources to support human populations and economies.

Explanation of Incorrect Options

Option B is incorrect because while scientific research and establishing zoos may involve trees, they are not primary purposes for cutting down trees in forests.

Option C is also incorrect as expanding urban areas and increasing tourism do not directly necessitate cutting down trees; rather, they can often be achieved through sustainable practices.

Option D is misleading because while trees can be used to manufacture medicines and cosmetics, these are not the primary reasons for cutting down trees in forests.

Desertification refers to the conversion of fertile land into deserts. This process is primarily caused by various factors, including climate change and human activities such as deforestation and unsustainable agricultural practices.

Explanation of Correct Answer

The correct answer is C because desertification specifically involves the degradation of land in arid, semi-arid, and dry sub-humid areas, resulting in the loss of productivity and the transformation of fertile land into desert.

Explanation of Incorrect Options

• A: Formation of new deserts - This option is misleading as desertification is about the degradation of existing fertile land rather than the creation of new deserts.
• B: Increased soil fertility - This is incorrect because desertification leads to a decrease in soil fertility, not an increase.
• D: Enhancement of plant growth - This option is also incorrect as desertification results in reduced vegetation and plant growth due to the loss of fertile soil.

Explanation of Correct Answer

The correct answer is Carbon Dioxide. Deforestation reduces the number of trees available to absorb carbon dioxide during photosynthesis. As trees are cut down, less carbon dioxide is utilized, leading to an increase in its levels in the atmosphere, which contributes to global warming.

Explanation of Incorrect Options

• Oxygen: Deforestation does not increase oxygen levels; in fact, it decreases them because fewer trees mean less oxygen is produced through photosynthesis.
• Nitrogen: The level of nitrogen in the atmosphere is not significantly affected by deforestation. Nitrogen is abundant in the atmosphere and is not directly related to tree cover.
• Hydrogen: Hydrogen levels in the atmosphere are not influenced by deforestation. This element is not produced or consumed in significant amounts by trees.

The correct answer is Biosphere. The biosphere is the global sum of all ecosystems, where living organisms exist and interact with their environment. It includes land, water, and the atmosphere, supporting life on Earth.

Explanation of Incorrect Options

• Xerosphere: This term is not commonly used in scientific literature and does not refer to a recognized part of the Earth.
• Lithosphere: This refers to the rigid outer layer of the Earth, consisting of the crust and upper mantle, but it does not specifically denote the area where living organisms exist.
• Microsphere: This term typically refers to small spherical structures and is not used to describe a part of the Earth where life exists.

The correct answer is Conservation of biodiversity. Wildlife sanctuaries, national parks, and biosphere reserves are established primarily to protect various species of flora and fauna and their habitats. They serve as safe havens for wildlife, ensuring that ecosystems are preserved and biodiversity is maintained.

Explanation of Incorrect Options

• Commercial land use: This option is incorrect because wildlife sanctuaries and national parks are not intended for commercial exploitation; rather, they are protected areas aimed at conservation.
• Urban development: This option is incorrect as these protected areas are specifically designated to prevent urbanisation and maintain natural habitats.
• Agricultural expansion: This option is also incorrect because wildlife sanctuaries, national parks, and biosphere reserves are meant to restrict agricultural activities that could harm wildlife and their habitats.

Explanation of Correct Answer

The correct answer is More soil erosion. Deforestation leads to the removal of trees that anchor the soil, which increases the likelihood of soil erosion. Without vegetation, the soil is more susceptible to being washed away by rain and wind.

Explanation of Incorrect Options

• Improved fertility: This option is incorrect because deforestation typically decreases soil fertility due to the loss of organic matter and nutrients that trees provide.
• Increased water holding capacity: This is incorrect as deforestation generally reduces the soil's ability to retain water, leading to increased runoff and decreased moisture levels.
• Better texture: This option is also incorrect because deforestation can lead to a degradation of soil structure, making it less suitable for plant growth.

Explanation of Correct Answer

The correct answer is Disturbance of the water cycle. Deforestation disrupts the natural processes of the water cycle by reducing the number of trees that can absorb and release water through transpiration. This leads to changes in rainfall patterns and can contribute to both droughts and floods.

Explanation of Incorrect Options

• Increased rainfall: This option is incorrect because deforestation typically leads to decreased rainfall due to the reduction in transpiration and changes in local climate.
• Stable groundwater levels: This is incorrect as deforestation can lead to lower groundwater levels due to reduced infiltration and increased runoff.
• Enhanced soil moisture: This option is also incorrect because deforestation generally decreases soil moisture levels, as there are fewer trees to retain water in the soil.

Explanation of Correct Answer

The correct answer is Satpura National Park, which is indeed part of the Pachmarhi Biosphere Reserve. This reserve includes one national park and two wildlife sanctuaries, with Satpura being the national park.

Explanation of Incorrect Options

• Sundarbans National Park: This national park is located in West Bengal and is known for its mangrove forests and the Royal Bengal tiger, but it is not part of the Pachmarhi Biosphere Reserve.
• Himalayan National Park: This refers to various national parks in the Himalayan region, none of which are associated with the Pachmarhi Biosphere Reserve.
• Gir National Park: Located in Gujarat, this park is famous for its Asiatic lions but is not part of the Pachmarhi Biosphere Reserve.

Explanation of Correct Answer

The correct answer is Deforestation. Deforestation refers to the clearing of forests, which is a significant threat to biodiversity. It leads to habitat loss for many species, disrupting ecosystems and contributing to the extinction of various plants and animals.

Explanation of Incorrect Options

• Urbanisation: While urbanisation contributes to habitat loss and can threaten wildlife, it is a broader process that includes various factors, including deforestation.
• Industrialisation: This process can lead to pollution and habitat destruction, but it is not as direct a threat to biodiversity as deforestation.
• Pollution: Pollution affects ecosystems and species health but is often a consequence of other activities, including industrialisation and urbanisation, rather than a direct cause of habitat loss.

Explanation of Correct Answer

The correct answer is Increases the temperature. Increased levels of carbon dioxide (CO2) in the atmosphere enhance the greenhouse effect, leading to a rise in Earth's average temperature. This phenomenon is a significant contributor to global warming.

Explanation of Incorrect Options

• Decreases the temperature: This option is incorrect because carbon dioxide does not have a cooling effect; rather, it traps heat in the atmosphere.
• Stabilises the temperature: This option is misleading as increased CO2 levels do not stabilise temperatures but contribute to their increase.
• Has no effect on temperature: This option is incorrect as scientific evidence shows that rising CO2 levels significantly impact global temperatures.

Explanation of Correct Answer

The correct answer is Species found exclusively in a particular area. Endemic species are defined as those species that are native to and restricted to a specific geographical region. They are not naturally found anywhere else in the world.

Explanation of Incorrect Options

• Species found in zoos: This option is incorrect because endemic species are not defined by their presence in zoos; they are defined by their geographical exclusivity.
• Species common in urban areas: This option is misleading as it refers to species that thrive in urban environments, which can be widespread and not necessarily endemic.
• Species that migrate annually: This option is incorrect because migratory species are those that move from one habitat to another, which is contrary to the definition of endemic species that remain in a specific area.

Explanation of Correct Answer

The correct answer is Biosphere reserve. Biosphere reserves are designated areas that encompass large regions of land and water, aimed at conserving biodiversity and promoting sustainable development. They are typically larger than national parks and wildlife sanctuaries, which focus more on specific species or ecosystems.

Explanation of Incorrect Options

• Wildlife sanctuary: While wildlife sanctuaries provide protection for animals and their habitats, they are generally smaller in size compared to biosphere reserves.
• Botanical garden: Botanical gardens are primarily focused on the cultivation and display of plants for education and research, and do not serve the same purpose as protected areas for wildlife conservation.
• National park: National parks are protected areas for wildlife and natural resources, but they are usually smaller than biosphere reserves and have more restrictions on human activities.

Migratory birds fly to distant areas annually due to climatic changes, often to escape harsh weather conditions in their natural habitats and to find more hospitable environments for laying eggs.