UPSC Prelims 2024 Analysis

Explanation

Statement-I: The Indian Flying Fox is placed under the vermin category in the Wild Life (Protection) Act, 1972.

The flying fox (Pteropus giganteus) is generally considered a vermin as they raid orchards. It had a similar official status under Schedule V of the Wildlife (Protection) Act of 1972

Though now it is put on the Schedule II list entailing a higher degree of protection.

Statement-II: The Indian Flying Fox feeds on the blood of other animals.

This statement is incorrect. The Indian Flying Fox is a frugivore, meaning it primarily feeds on fruits, nectar, and flowers, not on the blood of other animals.

Hence, statement 1 is correct while statement 2 is incorrect.

Explanation

Explanation:

• Butterflies: Some butterfly species, like the Monarch butterfly, are poisonous. They consume milkweed during their larval stage, which makes them toxic to predators.

• Fish: Many fish species are poisonous, such as pufferfish, lionfish, and stonefish. They possess venom as a defense mechanism.

• Frogs: Poison dart frogs are a well-known example of poisonous frogs. Their skin secretes toxins that can be deadly.

Therefore, all three groups have poisonous species.

Explanation

• Statement 1: Lions do not have a particular breeding season.: This statement is correct. Lions can breed throughout the year, but they do show some seasonal preferences depending on their location and environmental factors like rainfall.

• Statement 2: Unlike most other big cats, cheetahs do not roar.: This statement is correct. Cheetahs have a different vocal structure compared to lions, tigers, leopards, and jaguars, preventing them from roaring. They purr, chirp, and make other bird-like sounds.

• Statement 3: Unlike male lions, male leopards do not proclaim their territory by scent marking.: This statement is incorrect. Both male lions and male leopards use scent marking extensively to define their territories. They spray urine and scrape the ground, leaving both olfactory and visual signals for other cats.

Therefore, only statements 1 and 2 are correct.

Explanation

• Insolation reaches the earth's surface in short waves and heat is radiated from the earth in long waves, Hence energy leaving the earth's surface i.e. terrestrial radiation heats up the atmosphere more than the incoming solar radiation i.e. insolation.

Hence, statement 1 is incorrect.

• Greenhouse gases in the atmosphere (such as water vapour and carbon dioxide) absorb most of the Earth's emitted longwave infrared radiation, which heats the lower atmosphere.

Hence, statement 2 is correct.

Explanation

Explanation:

• Membrane Bioreactors are often discussed in the context of: D. Wastewater treatment technologies.

• Membrane Bioreactors (MBRs) combine a membrane process like microfiltration or ultrafiltration with a biological wastewater treatment process. 

• They are used to improve the quality of treated wastewater and are known for their efficiency in removing contaminants.

Explanation

Power plants burning fossil fuels (coal, oil, and, to a lesser extent, natural gas) are the largest source of sulfur dioxide emissions globally. Coal, in particular, contains high levels of sulfur, and when burned, it releases large amounts of SO₂.   

• Locomotives, especially older ones, use diesel fuel which contains sulfur. While locomotives do contribute to sulfur dioxide (SO₂) emissions, their contribution is relatively minor compared to larger industrial sources.  

• Ships, particularly large cargo vessels and tankers, often use bunker fuel, a heavy, sulfur-rich fuel oil. This contributes significantly to SO₂ emissions, particularly in maritime regions.  However, they are still overshadowed by emissions from power plants 

• The process of extraction of metals from ore involves heating ores that contain sulfur compounds, releasing SO₂ into the atmosphere. However, its contribution is less than that of power plants.

Explanation

Explanation:

1. Carabid beetles: Many carabid beetles are predatory, and some species are known to be parasitoids, particularly of other insects. 

2. Centipedes: Centipedes are predatory arthropods and not parasitoids. They hunt and kill their prey.

3. Flies: The order Diptera (flies) includes a large number of parasitoid species. For example, Tachinid flies are parasitoids of various insects.

4. Termites: Termites are not parasitoids. They are social insects that primarily feed on wood and other plant matter.

5. Wasps: The order Hymenoptera (wasps, bees, ants) has numerous parasitoid species. Many wasp species are parasitoids, laying their eggs on or in other insects.

Therefore, parasitoid species are found in Carabid beetles, Flies, and Wasps.

Explanation

Explanation:

• Statement 1: PFAS are found to be widespread in drinking water, food and food packaging materials. This statement is TRUE. PFAS are used in a wide range of consumer products, and due to their persistence, they can leach into the environment and contaminate water sources, food, and packaging materials.

• Statement 2: PFAS are not easily degraded in the environment. This statement is TRUE. PFAS are known as 'forever chemicals' because the strong carbon-fluorine bond makes them highly resistant to natural degradation processes. This persistence leads to their accumulation in the environment.

• Statement 3: Persistent exposure to PFAS can lead to bioaccumulation in animal bodies. This statement is TRUE. Because PFAS don't break down easily, they can build up in the tissues of animals and humans over time, leading to potential health concerns.

Therefore, all three statements are correct.

Explanation

Explanation:

Congo Basin Peatlands: The Congo Basin in Central Africa is home to the world's largest tropical peatland complex. This vast peatland stores an immense amount of carbon, estimated to be equivalent to about three years of global fossil fuel emissions. 

Importance of Peatlands: Peatlands are a critical carbon sink. They store more carbon than all the world's forests combined. When peatlands are drained or degraded, this stored carbon is released into the atmosphere, contributing to climate change. The Republic of Congo, the Democratic Republic of Cong and Indonesia are parties to the Brazzaville Declaration, aimed at protecting the Cuvette Centrale region in the Congo Basin, the world’s largest tropical peatlands, from unregulated land use and preventing its drainage and degradation. 

Other Options: 

• Amazon Basin: While the Amazon is known for its vast rainforests, it is not the primary location of the world's largest tropical peatland.

•  Kikori Basin: The Kikori Basin is located in Papua New Guinea and contains significant peatlands, but not the largest tropical peatland complex.

• Rio de la Plata Basin: This basin in South America is primarily known for its grasslands and is not associated with major peatland areas.

Explanation

Statement-I: Correct

• Chewing gums are a source of environmental pollution due to several factors:

  •  Non-biodegradable gum base: Traditional chewing gums often contain polymers like polyisobutylene, polyvinyl acetate, or polyethylene, which do not decompose easily in the environment.

  •  Littering: Discarded chewing gum remains on sidewalks, streets, and other public spaces, creating an eyesore and requiring significant resources for removal.

Statement-II: Correct and explains Statement-I

• The plastic-like polymers used as gum bases in many chewing gums are the primary reason they are difficult to biodegrade. These polymers contribute significantly to the environmental persistence of chewing gum litter.

Therefore, the correct option is (A): Both Statement-I and Statement-II are correct and Statement-II explains Statement-I.

Explanation

Fig-Wasp Mutualism: Figs and fig wasps share an obligate mutualistic relationship, meaning they are entirely dependent on each other for survival and reproduction. Fig wasps are the only insects that can pollinate fig trees, and fig trees are the sole source of food and shelter for developing fig wasps.

Highly Specialized Pollination: The fig fruit (technically a syconium) has its flowers enclosed within. Female fig wasps enter the syconium through a tiny opening called the ostiole. They lay eggs inside and pollinate the flowers in the process.

Coevolution: This intricate relationship is a classic example of coevolution, where two species have evolved together over millions of years, with each species' adaptations influencing the other's.

The other options are incorrect:

• Mahua (B): It is pollinated by various insects and even bats. Mahua (Madhuca indica) is found in the dry deciduous type of forests like the Forests of Chhattisgarh and Jharkhand.

• Sandalwood (C): It is primarily pollinated by bees and flies. Sandalwood is a dry deciduous forest species native to China, India, Indonesia, Australia, and the Philippines. Sandalwood is listed as Vulnerable in the IUCN Red list. Sandalwood grows as a partial or hemiparasite, relying on the presence of four or five other trees nearby. Beneath the ground, its roots develop a haustorium, an octopus-like structure that attaches to the host tree's roots, drawing water and nutrients from them. 

Silk cotton (D): It is pollinated by bats and birds. The Silk Cotton Tree is a tropical deciduous tree native to the Indian subcontinent and other parts of Southeast Asia. It produces a capsule that, when ripe, contains white fibres like cotton.

Explanation

•  Cicada: Known for their loud buzzing sounds, cicadas are insects.

•  Froghopper: Also known as spittlebugs, they are small, jumping insects.

•  Pond Skater: These insects are known for their ability to walk on the surface of water.

All three organisms are classified as insects.

Explanation

Explanation:

• Agricultural residues: These include materials like crop stalks, husks, and leaves. They are a viable source of biomass that can be converted into biofuels, including Sustainable Aviation Fuel (SAF).

• Corn grain: Corn grain is a source of sugars that can be fermented to produce ethanol, a biofuel. While ethanol is primarily used in gasoline blends, it can also be further processed into SAF.

• Wastewater treatment sludge: This sludge is rich in organic matter. Through processes like anaerobic digestion, it can produce biogas, which can be further converted into SAF.

• Wood mill waste: This includes sawdust, wood chips, and bark. These lignocellulosic materials can be converted into biofuels through various thermochemical or biochemical processes, ultimately leading to SAF production.

Therefore, all four materials can be used as feedstock for producing Sustainable Aviation Fuel.