UPSC Prelims 2020 Analysis

Explanation

The description mentions three spacecraft in an equilateral triangle formation with million-kilometre sides using lasers for measurement. This matches the design of the Evolved Laser Interferometer Space Antenna (eLISA) mission. eLISA is a proposed space observatory aiming to detect gravitational waves using precisely positioned spacecraft.

Voyager-2 and New Horizons are single spacecraft on exploration missions, not designed for gravitational wave detection.

LISA Pathfinder was a precursor mission to test technologies for eLISA, not the full mission itself.

Therefore, based on the details provided, the experiment refers to the Evolved LISA mission.

Explanation

In Andhra Pradesh, drones were banned from spraying fertilizers, however, it is practised in many parts of the world.

In Peru, a crater was inspected with the help of drones.

It has also been used for collecting water samples from aquatic animals to get their DNA data.

All three functions mentioned have been performed in different parts of the world.

Explanation

In India, the term "Public Key Infrastructure" (PKI) is used in the context of digital security infrastructure.

PKI is a system that facilitates secure electronic communication and transactions by using digital certificates, certificate authorities, and other related components. It plays a vital role in ensuring the authenticity, confidentiality, and integrity of data exchanged online.

Explanation

Statement 1 is correct. Visible Light Communication (VLC) utilizes the electromagnetic spectrum within the visible light range, which is roughly between 375 nm (violet) and 780 nm (red).

Statement 2 is incorrect. VLC is not considered long-range communication compared to other optical wireless technologies like fibre optics. Its range is typically limited to shorter distances due to factors like signal power and signal degradation.

Statement 3 is correct. VLC has the potential to transmit large amounts of data at high speeds, often faster than Bluetooth technology, especially in scenarios where high data transfer rates are required.

Statement 4 is also correct. VLC does not use radio frequencies (RF) like traditional wireless communication technologies, and therefore, it does not suffer from electromagnetic interference (EMI) that can affect RF-based systems.

Explanation

AI is now being used to analyze industrial data, optimize processes, and predict energy usage patterns. This allows for targeted interventions to reduce overall consumption.

AI can now generate more creative and coherent text formats compared to 2020. While still under development, some AI-generated content can be quite engaging, blurring the lines between human and machine creation.

AI has become a powerful tool in medical diagnosis. AI algorithms can analyze vast amounts of medical data, identify complex patterns, and assist healthcare professionals in diagnosis and treatment planning.

Text-to-speech conversion using AI continues to be a well-established technology. AI can now generate natural-sounding speech with various accents and emotions, making it a valuable tool for various applications.

While significant wireless transmission of electricity over long distances remains a challenge, there has been progress in short-range wireless charging and localized energy transfer using AI-powered systems.

Note: From the current status of AI development, all the listed applications of AI are feasible. However, this question was asked by the UPSC in 2020 when Generative AI was yet to become mainstream. UPSC's official answer key gave 'B' as the correct answer.

Explanation

Statement 1 is correct. Blockchain technology operates as a decentralized and transparent ledger that records transactions across a network of computers. The ledger is publicly accessible, allowing anyone to inspect the transactions recorded on it. Additionally, no single user or entity has control over the entire blockchain network, as it is distributed among multiple nodes.

Statement 2 is incorrect. While blockchain technology is best known for its association with cryptocurrencies like Bitcoin, the blockchain itself is capable of recording various types of data beyond just financial transactions. Blockchain can be used to record and verify any type of digital information, such as contracts, identity documents, supply chain data, and more.

Statement 3 is correct. Blockchain technology enables the development of decentralized applications (DApps) that can operate without the need for central authority or permission. Developers can create applications that utilize the basic features of blockchain, such as transparency, immutability, and decentralization, without requiring approval from a central entity.

Explanation

Statement 1 is correct. Pneumococcal Conjugate Vaccines (PCVs) are effective in preventing several serious diseases caused by Streptococcus pneumoniae bacteria. This includes pneumonia, meningitis (inflammation of the meninges surrounding the brain and spinal cord), and sepsis (a life-threatening blood infection).

Statement 2 is also correct. The growing prevalence of antibiotic-resistant strains of Streptococcus pneumoniae is a major concern. PCV vaccination helps reduce dependence on antibiotics, particularly for these resistant strains. This lowers the risk of antibiotic overuse and emergence of further resistance.

Statement 3 is incorrect. While most people experience no serious side effects with PCV vaccines, there can be mild reactions like redness, swelling, or soreness at the injection site. Serious allergic reactions are rare.

Explanation

Steel slag can be used for several purposes, and all of the options listed are valid applications.

Statement 1 is correct. Steel slag is a common and cost-effective material for use in road base construction due to its high durability, strength, and drainage properties.

Statement 2 is correct. Crushed steel slag can be used as an amendment for agricultural soil. It can improve drainage, provide some essential nutrients, and even help suppress weeds.

Statement 3 is correct. Steel slag can be partially substituted for some raw materials in cement production, reducing the need for quarrying and lowering the environmental impact of cement manufacturing.

Therefore, the correct answer is 1, 2, and 3.

Explanation

Statement 1 is correct. Techniques like CRISPR-Cas9 allow the editing of genes in sperm or egg cells (germline cells) before fertilization. This can potentially correct genetic diseases passed on to future generations.

Statement 2 is correct. Genome editing in early embryos CRISPR and other techniques can be used to edit genes in embryos at a very early stage of development. This allows for correcting genetic defects before implantation in the womb, potentially preventing the child from inheriting the disease.

Statement 3 is correct. Scientists can reprogram adult human cells into induced pluripotent stem cells (hiPSCs) that have the potential to develop into any cell type. These hiPSCs can be injected into animal embryos, like pigs, to create chimeric embryos containing both human and animal cells. This technology is used for research purposes to study human development and disease.

All three statements are correct.

Explanation

Pronuclear transfer, in the context of human reproductive technology, is used for preventing mitochondrial diseases in offspring.

Here's why

• Mitochondria: These are cellular organelles with their own DNA (mitochondrial DNA or mtDNA) separate from nuclear DNA. Mutations in mtDNA can cause various inherited mitochondrial diseases that can affect organs like muscles, nerves, and the brain.
• Pronuclear Transfer Technique: This technique involves the fertilization of an egg with sperm. Then, the pronuclei (nuclei before fusion) from both sperm and egg are removed. These pronuclei are then injected into a donor egg that has had its own pronuclei removed, but has healthy mtDNA.

Explanation

Statement 1 is correct. Plant cells have rigid cell walls made of cellulose, a complex carbohydrate, which animal cells lack. Animal cells rely on a plasma membrane for structure and protection.

Statement 2 is incorrect. Both plant and animal cells have a plasma membrane, a phospholipid bilayer that controls what enters and leaves the cell. It's a fundamental component for all cells.

Statement 3 is correct. Mature plant cells typically have a single, large central vacuole that stores water, nutrients, and waste products. Animal cells can have vacuoles, but they are usually smaller and more numerous.

Explanation

IAEA safeguards are a set of technical safeguards applied by the IAEA to independently verify any nuclear facilities to check if it is not misused or deviated from peaceful uses.

IAEA Safeguards are meant to understand if imported/enriched uranium is not used for non-peaceful purposes.

New reactors under IAEA safeguards The decision will be based on the source of uranium.

Explanation

Statement 1 is correct. Carbon nanotubes are being explored for their potential use as drug and antigen carriers in the human body. Their unique properties allow them to attach drugs or antigens and deliver them to specific target cells.

Statement 2 is incorrect. While research is ongoing, using carbon nanotubes for artificial blood capillaries in the human body is still in the theoretical or experimental stages.

Statement 3 is correct. Carbon nanotubes show promise in developing biosensors due to their high electrical conductivity and sensitivity to changes in their environment. This makes them suitable for detecting biomolecules like enzymes, DNA, or toxins.

Statement 4 is partially true. Some studies have found that carbon nanotubes are non-degradable, also some studies have shown them to be degradable.

The official answer key of the UPSC has given 'C' as the correct answer.