Previous Year UPSC Questions

Explanation

Microbeads are manufactured solid plastic particles of less than one millimetre in their largest dimension. They are most frequently made of polyethene but can be of other petrochemical plastics such as polypropylene and polystyrene. They are used in exfoliating personal care products, toothpaste and in biomedical and health-science research.

Option (a) is correct: Microbeads can cause plastic particle water pollution and pose an environmental hazard for aquatic animals in freshwater and ocean water. NGT had earlier directed the GoI to test cosmetic products containing microbeads after a plea sought a ban on their use on the ground they are extremely dangerous for aquatic life and the environment.

Explanation

Methane hydrate is an ice-like substance formed when CH₄ and water combine at low temperature (up to 250C) and moderate pressure (greater than 3-5 MPa, which corresponds to combined water and sediment depths of 300 to 500 m).

Statement 1 is correct: Owing to the melting of ice, global warming might trigger the release of methane gas from these deposits hence having a significant impact on climate change.

Statement 2 is correct: Sediment and sedimentary rock units below Arctic permafrost have the temperature and pressure conditions suitable for the formation and stability of methane hydrate.

Statement 3 is correct: Methane is relatively short-lived in the atmosphere; a molecule of methane is oxidised to water and carbon dioxide within a decade or so, mainly by reaction with other trace gases.

Explanation

Burning stubble (parali) is the process of removing crop residue from the field in order to prepare it for the next crop. Open stubble burning releases a lot of harmful pollutants into the air, including smoke, particles, greenhouse gases (CO₂, N₂O, O₃ CH₄), air pollutants (CO, NH₃, NOx, SO₂, NMHC), and volatile organic compounds. These pollutants are dangerous to human health. Husk burning reduces the fertility of the soil by destroying its nutrients. When stubble burns, heat is produced that permeates the soil, causing the loss of moisture and beneficial microbes.

Explanation

Statement 1 is incorrect: It was the 39th Constitutional Amendment (1975), passed during the Emergency, that placed elections for key offices like Prime Minister beyond judicial review. The 44th Amendment (1978) reversed several provisions of the 42nd Amendment, restoring civil liberties and the right to property.

Statement 2 is correct: The 99th Constitutional Amendment aimed to establish the National Judicial Appointments Commission (NJAC). But in 2015, the Supreme Court struck it down, affirming the collegium system. Justice JS Kehar, who was part of the bench that struck down the NJAC, emphasized that NJAC undermined the judicial independence which is crucial for safeguarding citizens’ rights.

Explanation

Statement 1 is incorrect: Though the 42nd Amendment Act of 1976 curtailed the power of HC in judicial review and debarred the HC from considering the constitutional validity of any central law. But the 43rd Amendment Act of 1978 restored the original position of the HC. Moreover now the HC is considered as the principal civil courts of original jurisdiction in each state and union territory. They can declare any central law to be constitutionally invalid in their jurisdiction.

Statement 2 is incorrect: The Constitution of India allows for amendments under Article 368 but the Supreme Court has the authority to review constitutional amendments, particularly to ensure that such amendments do not violate the basic structure of the Constitution. The Kesavananda Bharati case (1973) established the basic structure doctrine, where the Supreme Court ruled that Parliament could amend the Constitution but could not alter its basic structure.

Explanation

Statement 1 is correct: The Industrial Employment (Standing Orders) Central (Amendment) Rules, 2018 introduced fixed-term employment, allowing companies to hire workers for a specific period based on written contracts. Employers are not required to provide retrenchment benefits or notice periods for non-renewal of contracts, making it easier to terminate employment. Once the contract ends, the employer is not obliged to provide further employment. This effectively makes it easier for companies to let go of workers without facing legal hurdles.

Statement 2 is correct: As per the amendment rules, temporary workers, including those on fixed-term contracts, do not require a notice of termination if their contract expires naturally. The employer is not obligated to provide a prior notice period or severance pay unless stated in the contract.

Explanation

There is a renewed interest in two dominant methods of geoengineering such as stratospheric sulphate aerosol increase and cirrus cloud thinning aims to reduce global warming effects. Geoengineering, often known as climate intervention, is the deliberate and extensive modification of the Earth’s climatic system with the intention of reducing global warming. The stratosphere can be injected with sulphate aerosol particles to block some of the sun’s rays and possibly cool the planet. Sulphur droplets are good at scattering the sun’s light back out into space and it does not heat the stratosphere as much as other aerosols.

Explanation

Denisovans were an extinct hominin species closely related to Neanderthals and modern humans. Denisovans are an extinct species of archaic humans who lived around 50,000 to 300,000 years ago. They were first identified from DNA extracted from fossils found in the Denisova Cave in Siberia, Russia in 2010. They are closely related to Neanderthals and also interbred with early modern humans (Homo sapiens). Genetic studies show that traces of Denisovan DNA can still be found in present-day humans, especially in Melanesians, Australian Aboriginals, and some East Asian populations.

Explanation

As per the Indian Nitrogen Assessment report, 2017, the share of agriculture in total GHG emissions has gradually declined from 28% in 1994 to 14% in 2016. Agricultural emissions in India are primarily from the livestock sector (54.6%) and the use of nitrogenous fertilizers (19%). Rice cultivation in anaerobic conditions accounts for a major portion of agricultural emissions (17.5%).

Statement 1 is correct: Agricultural soils release nitrogen oxides into the environment Fertilizers (especially nitrogen-based like urea) lead to the emission of nitrous oxide (N₂O), a greenhouse gas. Microbial processes such as nitrification and denitrification release NO, NO, and NO.

Statement 2 is correct: Cattle release ammonia into the environment Cattle excrete urea in urine, which breaks down into ammonia (NH₃) through microbial action. Livestock farming is a major contributor to ammonia emissions.

Statement 3 is correct: Poultry industry releases reactive nitrogen compounds into the environment Poultry litter (manure, bedding material, and feed waste) contains nitrogen compounds that can convert into ammonia, nitrates, and nitrites. This contributes to air and water pollution.

Explanation

Option (a) is correct: Maintenance of law and order is not a sub-index of the Ease of Doing Business Index. While law and order are important for the business environment, the index does not specifically measure this factor. Options (b), (c) and (d) are incorrect:

Paying taxes is indeed a sub-index. It evaluates the tax system’s efficiency, ease of compliance, and tax rates. Registering property is a sub-index that measures the ease of transferring property ownership and registering real estate. Dealing with construction permits is a sub-index. It assesses the procedures, time, and cost to build a warehouse, considering factors like zoning and construction approvals.