Previous Year UPSC Questions

Explanation

Lake Victoria is the largest lake in Africa and the largest tropical lake in the world. It is shared by three countries:

Tanzania, Uganda, and Kenya. The lake’s boundaries serve as international borders, most notably between Tanzania and Uganda. Its significance extends beyond political boundaries, as it plays a crucial role in the regional ecosystem and serves as a vital resource for the surrounding populations.

Explanation

Endocrine glands secrete hormones that regulate various bodily functions, from growth and metabolism to stress responses. A is matched with 2: The gonads (ovaries in females and testes in males) are responsible for producing sex hormones. In females the ovaries secrete progesterone which plays a key role in regulating the menstrual cycle and maintaining pregnancy. In males the testes primarily produce testosterone but it also produces progesterone in smaller amounts. B is matched with 3: Known as the master gland, pituitary gland secretes growth hormone (GH) (stimulates growth, cell reproduction, and regeneration), thyroid-stimulating hormone (TSH) (regulates metabolism), prolactin (stimulates milk production), and antidiuretic hormone (ADH) (maintains water balance). C is matched with 1: Pancreas regulates blood sugar levels through insulin (lowers blood glucose) and glucagon (raises blood glucose) and plays a major role in carbohydrate, fat, and protein metabolism. D is matched with 4: The adrenal glands located on top of the kidneys produce cortisone, a glucocorticoid hormone involved in stress response, metabolism, and immune regulation. Cortisone is part of the body’s natural response to stress and inflammation.

Explanation

Option (d) is correct: During intense exercise muscles rely on anaerobic respiration (without oxygen) to produce energy quickly. This process breaks down glucose into pyruvate, which is then converted into lactic acid (or lactate) in the absence of sufficient oxygen. The buildup of lactic acid in muscle tissues lowers the pH which causes a burning sensation and muscle fatigue.

Option (a), (b) and (c) are incorrect:

While a decrease in oxygen supply can contribute to fatigue but it is not the primary cause of the immediate sensation of muscle fatigue. Prolonged or intense exercise can cause microscopic damage to muscle fibers which causes delayed-onset muscle soreness (DOMS). However, this damage does not cause the immediate sensation of fatigue during exercise. Glucose is a primary energy source for muscles during exercise. While glycogen (stored glucose) depletion can contribute to fatigue during prolonged endurance activities (e.g., marathons) but it is not the primary cause of the acute fatigue and burning sensation

Explanation

The small pouch containing silica gel found in bottles of medicine (tablets or powder) is primarily used to absorb moisture. Silica gel is a desiccant, meaning it has a high affinity for water molecules. It absorbs moisture from the surrounding environment, preventing the tablets or powder from degrading due to humidity. This helps maintain the stability and efficacy of the medicine. Silica gel has a porous structure that traps water molecules through adsorption. Moisture can cause tablets to crumble or powders to clump, reducing their effectiveness and shelf life.

Explanation

To reach the final of the Australian Open, the first grand slam of the year 2000, Martina Hingis defeated Conchita Martinez 6-3,6-2.

Explanation

Since 1980, the tertiary sector (services sector) has consistently shown an increasing trend in its contribution to India’s Gross Domestic Product (GDP). This transformation is largely attributed to the rapid expansion of IT services, telecommunications, financial services, trade, and tourism. The sector’s growth was further fueled by the liberalization policies of the 1990s, which opened up the Indian economy to global markets, fostering private sector participation and foreign investment in service-oriented industries. Additionally, advancements in technology, rising demand for skilled professionals, and urbanization significantly boosted the role of services, making it the largest contributor to India’s GDP by the late 1990s. This structural shift highlights India’s transition from an agrarian economy to one dominated by the services sector. As per the Economic Survey 1998-99, the services sector contributed nearly 45% to India’s GDP by the late 1990s, surpassing agriculture and industry as the key driver of economic growth.

Explanation

Abdul Qadir Badayuni was an Indian historian, writer, and translator who lived during the Mughal Empire. He is notable for translating key Hindu texts, including the Ramayana and the Mahabharata (Razmnama), into Persian.

Option (c) is correct: Muhammad-bin-Tughlaq (1325-1351) was known for his controversial and ambitious policies. It includes the:

Introduction of token currency Shifting the capital from Delhi to Daulatabad, and aggressive expansionist campaigns. The quote "The king was freed from his people and they from their king" was made by Badauni on the death of Muhammad-bin-Tughlaq.

Explanation

"Aryan" primarily refers to a linguistic or speech group rather than an ethnic or racial group. It is associated with the Indo-Aryan languages, which are a branch of the larger Indo-European language family. The term was historically used to describe the speakers of these languages, who migrated to the Indian subcontinent and other parts of Asia. However, the details of the migration and the exact identity of these groups remain subjects of scholarly debate.

Explanation

First Anglo Maratha War (1775-82) was fought between the British East India Company and Maratha Confederacy in India. The war began with the Treaty of Surat and ended with the Treaty of Salbai. The war saw British defeat and restoration of positions of both the parties before the war. The Second Anglo-Mysore War (1780-1784) saw Hyder Ali and Tipu Sultan fight the British after their betrayal. Hyder’s forces advanced to Madras (1780), but after his death (1782), Tipu continued the war. It ended with the Treaty of Mangalore (1784), restoring territories and maintaining the status quo. First Anglo Burmese War (1824-26) was the first of three Anglo-Burmese wars, which eventually led to British control over Burma. Anglo Afghan War (1838/1839-42) was fought between the British East India Company and the Kingdom of Afghanistan, primarily over British concerns regarding Russian influence in Central Asia.

Explanation

The introduction of the Bt gene into the cotton genome provides effective protection against damage caused by insects, significantly reducing the need for chemical pesticides. Assertion (A) is true: Insect-resistant transgenic cotton, known as Bt cotton, has been developed by inserting the Bt gene into cotton plants. Reason (R) is true: This gene, derived from the bacterium Bacillus thuringiensis, enables the plant to produce a protein toxic to specific insect pests, such as bollworms, while being harmless to humans and non-target organisms. Since the Bt gene’s origin from Bacillus thuringiensis directly explains its role in imparting insect resistance. Hence, both the assertion and the reason are true, and the reason correctly explains the assertion.