Previous Year UPSC Questions

Explanation

Insulin is a protein-based hormone produced by beta cells in the pancreas, specifically in the Islets of Langerhans. It consists of two peptide chains (A and B) connected by disulfide bonds and plays a crucial role in regulating blood glucose levels. By promoting glucose uptake in cells, it helps maintain energy balance and prevents hyperglycemia. Insulin was first discovered by Frederick Banting and Charles Best in 1921. It is the first recombinant DNA-based drug approved for human use.

Explanation

Statement 1 is incorrect: Pangolins (scaly anteaters) are fascinating toothless mammals covered in protective keratin scales. They use their long, sticky tongues to capture ants and termites, making them nature’s pest controllers. India is home to two species of pangolins:

Indian Pangolin (Manis crassicaudata) is found across most parts of India, except for the northeastern states. Chinese Pangolin (Manis pentadactyla) inhabits the forests of northeast India, including Assam, Arunachal Pradesh, and Meghalaya. Pangolins are the most trafficked mammals in the world due to demand for their scales and meat.

Statement 2 is correct: Hoolock Gibbon is India’s only ape species and is a true acrobat of the rainforest. Unlike monkeys, gibbons lack tails and move gracefully through the trees using brachiation (swinging from branch to branch). These lesser apes are found in Northeast India, especially in Assam (Hoollongapar Gibbon Sanctuary) Arunachal Pradesh, Meghalaya, Mizoram, Manipur, Nagaland and Tripura. Hoolock gibbons are known for their melodious calls, which echo through the dense forests. Sadly, habitat destruction and deforestation have put them at risk.

Explanation

The term "long bone" refers to bones that are longer than they are wide such as the femur and humerus. The bone marrow within these long bones is a primary site for lymphocyte production. This process is known as lymphopoiesis and involves the differentiation of hematopoietic stem cells into various lymphocyte types such as B cells, T cells, and natural killer cells.

Explanation

Statement 1 is correct: The femur, or thigh bone is the longest and strongest bone in the human body. It stretches from the hip to the knee and provides crucial support and stability, allowing us to walk, run, and jump. The femur can withstand forces up to 816-1,134 kg before breaking, making it one of the strongest structures in our skeletal system.

Statement 2 is correct: Cholera is a severe bacterial infection caused by Vibrio cholerae. It spreads mainly through contaminated water or food, leading to acute diarrhea and dehydration. In extreme cases a person with can lose up to 20 liters of fluid per day making rapid treatment with rehydration therapy essential.

Statement 3 is incorrect: Athlete’s foot (Tinea Pedis) is not caused by a virus, but by fungal infection. Dermatophyte fungi thrive in warm, damp environments like locker rooms, swimming pools, and sweaty shoes. The infection causes itchy, peeling, and cracked skin between the toes, making it a common concern among athletes and hence the name.

Explanation

Malaysia is not part of the Mekong River basin. The river does not flow through Malaysia at any point. Malaysia’s major rivers include the Rajang River and Kinabatangan River. The Mekong River is one of the longest rivers in Asia (about 4,350 km long). It originates in China’s Tibetan Plateau and flows through six countries: China, Myanmar, Laos, Thailand, Cambodia, and Vietnam before emptying into the South China Sea.

Explanation

Option (d) is correct: Latvia is a Baltic country in Northern Europe, bordered by four countries: Estonia to the north, Russia to the east, Belarus to the southeast, and Lithuania to the south. It also has a western coastline along the Baltic Sea. Latvia does not share a border with Poland. Options (a), (b) and (d) are incorrect:

Latvia shares a border with Russia to the east, specifically in the Pskov and Leningrad regions. Latvia is directly north of Estonia, and both countries share a common border. Lithuania borders Latvia to the south, making this option incorrect.

Explanation

A is matched with 1: The Black Sea is an inland sea in south-eastern Europe. It is bordered by six countries: Bulgaria, Romania, Ukraine, Russia, Georgia, and Turkey. Bulgaria’s eastern coastline lies along the western edge of the Black Sea, providing it with significant maritime access. This strategic position has historically facilitated trade and cultural exchanges between Bulgaria and other Black Sea nations. B is matched with 3: The Red Sea is a seawater inlet of the Indian Ocean. It is situated between northeastern Africa and the Arabian Peninsula. It is bordered by several countries, including Egypt to the northwest, Sudan to the southwest, and Eritrea to the southeast. Djibouti and Saudi Arabia lie to the east, while Yemen is situated to the southeast. The Red Sea is also connected to the Mediterranean Sea through the Suez Canal and to the Arabian Sea via the Bab el-Mandeb Strait. C is matched with 2: The Yellow Sea is a marginal sea of the Western Pacific Ocean. It lies between mainland China and the Korean Peninsula. D is matched with 4: The Caspian Sea is recognized as the world’s largest inland body of water, and is bordered by five countries, namely, Kazakhstan, Russia, Azerbaijan, Iran, and Turkmenistan.

Explanation

Option (d) is correct: Venezuela is situated on the northern coast of South America, bordered by the Caribbean Sea to the north, Colombia to the west, Brazil to the south, and Guyana to the east. Notably, Venezuela does not share a border with Panama; the two countries are separated by Colombia. Options (a), (b) and (c) are incorrect: Panama, a Central American nation, is strategically positioned on the Isthmus of Panama, connecting North and South America. It shares its western border with Costa Rica, while Colombia lies to the east. The Pacific Ocean forms its southern coastline, and the Caribbean Sea borders it to the north. This unique geography has established Panama as a critical conduit for international maritime trade, exemplified by the Panama Canal, which links the Atlantic and Pacific Oceans.

Explanation

Vijay Singh is a famous professional golfer from Fiji. He had a successful career in international golf, winning several major championships, including the PGA Championship and the Masters Tournament.

Explanation

V.V.S. Laxman holds the record for the highest score by an Indian in a Test match innings with his 281 against Australia in 2001 at Eden Gardens, Kolkata.