Explanation:

Carbon Nanotubes UPSC 2020 PYQ

Statement 1: They can be used as carriers of drugs and antigens in the human body.

This statement is correct. Carbon nanotubes are effective carriers for drugs and antigens in the human body. Their high surface area and ability to be functionalized with various biomolecules make them suitable for targeted drug delivery systems.

Statement 2: They can be made into artificial blood capillaries for an injured part of the human body.

This statement is not entirely accurate as of the current state of research. While carbon nanotubes have potential in biomedical applications, creating artificial blood capillaries is not currently feasible. Challenges include biocompatibility, integration with existing vasculature, and preventing clotting and immune responses.

Statement 3: They can be used in biochemical sensors.

This statement is correct. Carbon nanotubes are widely used in biochemical sensors. Their high electrical conductivity and surface area allow for sensitive and specific detection of biological molecules like glucose, DNA, and proteins.

Statement 4: Carbon nanotubes are biodegradable.

This statement is correct but requires some nuance. The biodegradability of carbon nanotubes depends on their functionalization and environment. Some types can degrade under specific conditions, such as in the presence of oxidative enzymes. However, degradation rates vary, and some forms may persist for extended periods in biological systems or the environment.

Given the analysis above, the correct answer is (c) 1, 3, and 4 only. Statement 2 is not entirely accurate with the current state of technology and understanding of carbon nanotubes in biomedical engineering, making options (a), (b), and (d) incorrect. This is the official answer but other websites are saying (d).

Explanation:

Paramitas and Bodhisattva for UPSC

The term ‘paramitas’ in Buddhist philosophy refers to the perfections or virtues that are cultivated as a way of purification by those aspiring to attain Buddhahood. The concept is particularly emphasized in Mahayana Buddhism and is central to the path of a Bodhisattva.

A Bodhisattva is a being who seeks Buddhahood through the systematic practice of these virtues, not just for their own liberation, but for the benefit of all sentient beings. The paramitas are considered essential qualities to be developed for the attainment of enlightenment and include generosity, morality, patience, effort, meditation, and wisdom, among others, depending on the tradition.

Thus, option (c) is the correct description of ‘paramitas’ in the context of the cultural history of India.

Explanation:

Aggregate money supply if you withdraw rs 1 lakh ?

The aggregate money supply in an economy is typically considered to include both physical currency (cash) in circulation and demand deposits (balances in bank accounts that can be accessed on-demand).

When you withdraw ₹1,00,000 in cash from your Demand Deposit Account, you are essentially converting one form of money (bank deposits) into another form of money (physical currency).

The total amount of money in the economy (the sum of physical currency and demand deposits) does not change due to this transaction. You have simply changed the composition of the money supply, not the total amount.

Therefore, the immediate effect on the aggregate money supply in the economy is to leave it unchanged.

Explanation:

If another global financial crisis happens ???

1. Not Depending on Short-Term Foreign Borrowings

This is a crucial strategy for any country looking to insulate itself from global financial crises. Short-term foreign borrowings can be highly volatile. In times of global financial stress, foreign investors may quickly withdraw their investments, leading to a sudden shortage of foreign currency, which can exacerbate the crisis for the borrowing country. By not depending heavily on such borrowings, a country can reduce its vulnerability to sudden stops and reversals of capital flows, which are common features of global financial crises.

2. Opening up to More Foreign Banks

While this can have benefits in terms of bringing in more capital and potentially more efficient banking services, it does not necessarily provide immunity against a global financial crisis. In fact, it could increase vulnerability in some cases. Foreign banks may quickly repatriate capital in times of global stress, exacerbating liquidity issues in the domestic market. Therefore, this option does not directly contribute to immunity against a global financial crisis.

3. Maintaining Full Capital Account Convertibility

This means allowing the free exchange of local currency for foreign currency and vice versa without restrictions. While it can encourage foreign investment and economic integration with global markets, full capital account convertibility also increases vulnerability to global financial shocks. It can lead to rapid and large-scale capital outflows during times of global financial stress, destabilizing the domestic financial system.

Therefore, the option that most directly contributes to some level of immunity against a global financial crisis for India is not depending on short-term foreign borrowings. Opening up to more foreign banks and maintaining full capital account convertibility, while having their own merits in certain contexts, do not directly offer protection against a global financial crisis and, in some scenarios, could even increase vulnerability.

Explanation:

Factors for exposure to benzene pollution:

1. Automobile Exhaust:

Benzene is a well-known component of gasoline and is emitted in automobile exhaust. Therefore, areas with heavy traffic or enclosed spaces like garages can have higher levels of benzene pollution.

2. Tobacco Smoke:

Tobacco smoke is a significant source of benzene exposure for both smokers and those exposed to secondhand smoke. It is one of the most hazardous sources of indoor air pollution in terms of benzene.

3. Wood Burning:

Burning wood can release benzene, among other volatile organic compounds (VOCs), into the environment. This is especially relevant in homes that use wood as a primary heating source or in areas where open burning is common.

4. Using Varnished Wooden Furniture:

Varnishes and paints can contain benzene and other VOCs, especially if they are solvent-based. However, once these finishes have dried and cured, the amount of benzene they emit is significantly reduced. The risk of exposure from varnished wooden furniture is generally lower compared to direct sources like smoke or exhaust, but it can still contribute to indoor air levels of benzene, especially in newly furnished or renovated spaces.

5. Using Products Made of Polyurethane:

Polyurethane foam, used in furniture, mattresses, and various building materials, can emit VOCs. However, benzene is not typically a significant component of the emissions from polyurethane products. The primary concern with polyurethane often relates to isocyanates used in its production and other VOCs, rather than benzene specifically.

Given the analysis:

• Automobile exhaust, tobacco smoke, and wood burning are direct sources of benzene pollution.
• Using varnished wooden furniture can be a source, albeit less direct and typically with lower exposure levels once the varnish has cured.
• Using products made of polyurethane is less about benzene exposure and more about other VOCs and chemicals.

Therefore, the most accurate answer, considering the directness and significance of benzene exposure, would be:

(a) 1, 2, and 3 only. This is also official UPSC Answer but other websites are saying d)

Explanation:

Public Key Infrastructure is used in the context of ?

The term “Public Key Infrastructure” (PKI) is used in the context of digital security infrastructure. PKI is a set of roles, policies, hardware, software, and procedures needed to create, manage, distribute, use, store, and revoke digital certificates and manage public-key encryption. The purpose of a PKI is to facilitate the secure electronic transfer of information for a range of network activities such as e-commerce, internet banking and confidential email. It is used to secure the identities of people, devices, and services, ensuring that communications and transactions can be trusted.

Explanation:

1. These vaccines are effective against pneumonia as well as meningitis and sepsis.

This statement is true. Pneumococcal Conjugate Vaccines (PCVs) are designed to protect against pneumococcal diseases caused by Streptococcus pneumoniae, which include pneumonia, meningitis, and sepsis. These diseases can be severe and sometimes fatal, especially in young children, the elderly, and individuals with certain health conditions that compromise their immune systems.

2. Dependence on antibiotics that are not effective against drug-resistant bacteria can be reduced.

This statement is also true. Overuse and misuse of antibiotics have contributed to the rise of antibiotic-resistant bacteria. By preventing pneumococcal diseases, PCVs reduce the need for antibiotics, thereby helping to slow down the development of antibiotic resistance.

3. These vaccines have no side effects and cause no allergic reactions.

This statement is not accurate. While PCVs are generally safe and well-tolerated, they can cause side effects and allergic reactions in some individuals, like any other vaccine. Common side effects include pain at the injection site, fever, irritability, and loss of appetite. Severe allergic reactions are rare but can occur.

Therefore, the statements 1 and 2 highlight the importance of using Pneumococcal Conjugate Vaccines in India, making option (b) the correct answer.

Explanation:

Genetic changes can be introduced in the cells that produce eggs or sperms of a prospective parent ?

Genetic changes can be introduced in the cells that produce eggs or sperms of a prospective parent. Techniques such as CRISPR-Cas9 have made it possible to edit the genome of germ cells (sperm and eggs), which can then pass these genetic changes to future generations. This approach has significant implications for eliminating genetic diseases but also raises ethical concerns.

Genome Editing at the Early Embryonic Stage

A person’s genome can be edited before birth at the early embryonic stage. Genome editing technologies like CRISPR can be used to edit the genome of embryos at the early developmental stage. This has been a subject of much debate, especially after the announcement of the birth of the first genetically edited babies in China in 2018, where CRISPR was used to edit embryos to make them resistant to HIV.

Human induced pluripotent stem cells

Human induced pluripotent stem cells (iPSCs) can be injected into the embryo of a pig. Research has been conducted where human iPSCs are introduced into the embryos of other species, such as pigs, to study the development of human organs within these animals for research and potential organ transplantation. This field is known as interspecies chimerism and has been explored as a way to potentially grow human organs in animals for transplantation, though it also faces significant ethical and technical challenges.

Explanation:

The experiment will employ a trio of spacecraft is Evolved LISA

The experiment described refers to the Evolved Laser Interferometer Space Antenna (eLISA) project, commonly referred to as LISA (Laser Interferometer Space Antenna). It involves a trio of spacecraft flying in formation in the shape of an equilateral triangle, with sides one million kilometers long, and using lasers to communicate between the craft.

LISA is a planned space mission by the European Space Agency (ESA) designed to detect and accurately measure gravitational waves — tiny ripples in the fabric of space-time — from astronomical sources. LISA aims to achieve this by deploying three spacecraft in a triangular formation, following Earth in its orbit around the Sun. The spacecraft will be positioned millions of kilometers apart, using laser interferometry to measure the minute changes in distances between them caused by passing gravitational waves.

This mission is distinct from the other options provided:

1. Voyager-2: Part of NASA’s Voyager program, which launched two spacecraft, Voyager 1 and Voyager 2, in 1977 to explore the outer planets and beyond. It is not designed for detecting gravitational waves.
2. New Horizons: A NASA mission launched to study Pluto and the Kuiper Belt. It conducted a flyby of Pluto in July 2015 and is continuing its journey through the Kuiper Belt. Like Voyager-2, it is not designed for gravitational wave detection.
3. LISA Pathfinder: A precursor mission to LISA, launched by the European Space Agency (ESA) to test technologies for detecting gravitational waves in space. While it was related to the LISA project, it was not the full gravitational wave observatory described in the question.

Therefore, the correct answer is Evolved LISA, which directly corresponds to the description of the experiment involving spacecraft in a triangular formation using lasers to detect gravitational waves.

Explanation:

Drones have become increasingly versatile tools, capable of performing a wide range of tasks across various fields. Let’s examine the feasibility of using drones for each of the activities mentioned:

Spraying pesticides on a crop field

Drones are already being used extensively in agriculture for various purposes, including the spraying of pesticides. They offer a precise and efficient means of applying pesticides, reducing the amount of chemicals used and minimizing human exposure to these potentially harmful substances. Drones equipped with spraying mechanisms can cover large areas quickly, making this task not only feasible but also increasingly common.

Inspecting the craters of active volcanoes

Drones are also used in the field of volcanology to inspect and monitor active volcanoes. They can fly into hazardous areas that are inaccessible or too dangerous for humans, collecting data and imagery that help scientists study volcanic activity, gas emissions, and predict eruptions. The use of drones in this context reduces the risk to human life and provides valuable information that might not be otherwise obtainable.

Collecting breath samples from spouting whales for DNA analysis

This is another area where drones have been successfully deployed. Researchers have used specially equipped drones, sometimes referred to as “snotbots,” to fly through the blow (the exhaled breath) of whales to collect DNA, microbiomes, and stress hormones. This non-invasive method of data collection is less stressful for the whales compared to traditional methods and provides scientists with important biological and ecological information.

Given the above, the correct answer is: (d) 1, 2, and 3