Previous Year UPSC Questions

Explanation

Stem cells are undifferentiated cells with the potential to develop into various specialized cell types, offering promise for regenerative medicine and disease treatment

Statement 1 and 2 are incorrect: The blastocyst stage of embryos is a common source of embryonic stem cells, but it is not the only source. Stem cells can also be derived from adult tissues (adult stem cells) and umbilical cord blood. As of current techniques, obtaining embryonic stem cells typically requires the destruction of the blastocyst. Alternative methods are being actively researched to derive stem cells without causing harm to the blastocyst.

Statement 3 is correct: Stem cells, such as embryonic stem cells have the ability to self-renew and regenerate themselves in vitro indefinitely under appropriate conditions. This property makes them valuable for research and therapeutic applications.

Statement 4 is correct: Indian research centers, such as the National Centre for Biological Sciences (NCBS) and the Indian Council of Medical Research (ICMR), have successfully created a few stem cell lines capable of differentiating into multiple tissue types.

Explanation

In the latter part of the 18th century, following the grant of Diwani (revenue collection rights) of Bengal by the Mughal emperor in 1765, the British East India Company began establishing contact with the Garos. The estates bordering the Garo Hills, previously semi-independent, came under British control. However, like the Mughals, the British did not seek to directly govern these estates. Instead, the Zamindars were entrusted with maintaining order, including controlling the Garos. Conflict between the Zamindars and Garos continued until it escalated, leading to the British annexation of the Garo Hills in 1873.

Explanation

Mudrarakshasa by Vishakhadatta is a political drama revolving around the strategic acumen of Chanakya (Kautilya) in securing Chandragupta Maurya’s rise to power. The play narrates the clever maneuvering by Chanakya to win over Rakshasa, a loyal minister of the Nanda dynasty, to Chandragupta’s side. It provides valuable insights into Mauryan administrative policies and the importance of realpolitik during this era.

Explanation

Option (c) is correct: A sun halo is caused by the refraction of sunlight through ice crystals in cirrus clouds, forming a ring of light around the sun. This phenomenon occurs when light bends as it passes through the hexagonal ice crystals, creating a halo effect in the sky. The angle at which light is refracted by the ice crystals typically forms a halo with a radius of about 22 degrees, often appearing as a bright, circular ring. Sun halos are more common in colder regions and can be seen when thin cirrus clouds are present in the upper atmosphere. Options (a), (b) and (d) are incorrect:

Water vapor in stratus clouds: Stratus clouds are low-level clouds composed of water droplets, not ice crystals. Ice crystals in cirro-cumulus clouds: Cirro-cumulus clouds are not as common for halo formation as cirrus clouds. Dust particles in stratus clouds: Dust does not cause the refractive effects required for a halo.

Explanation

Statement 1 is incorrect: Equatorial regions generally experience two main seasons: a wet season (due to intense convectional rainfall) and a dry season (caused by a temporary shift in wind patterns). These regions do not have four distinct seasons like temperate zones.

Statement 2 is incorrect: In a Mediterranean climate, summers are dry due to the dominance of subtropical high-pressure systems, while winters are wet due to cyclonic activity. This climate is commonly found in areas like Southern California, parts of Australia, and the Mediterranean basin itself.

Statement 3 is correct: In China-type climate rainfall occurs throughout the year. This climate is known as the humid sub-tropical climate and is typical of regions like southern China, Taiwan, and parts of southeastern United States.

Statement 4 is correct: Tropical highlands show vertical zonation of climates, where altitude impacts temperature and vegetation. Example: In the Andes, conditions transition from tropical climates at lower elevations to temperate and alpine climates at higher altitudes. As the altitude increases, temperatures drop, and the climate changes from tropical conditions at the base to cooler temperate or even alpine climates at higher elevations.

Explanation

Statement 1 is Incorrect: Sheikh Ahmad Sirhindi, known as Mujaddid Alf Sani, lived during the Mughal period and was a contemporary of Akbar and Jahangir long after Ibrahim Lodi (who ruled from 1517 to 1526).

Statement 2 is Correct: Sheikh Nasiruddin Chirag-i-Dehlavi was a prominent disciple of Sheikh Nizamuddin Auliya, carrying forward the Chishti Sufi order in Delhi.

Statement 3 is Incorrect: Sheikh Salim Chisti, a revered Sufi saint of the Chishti order, was associated with Akbar’s reign and was not contemporary to Aurangzeb. He is known for his spiritual influence at Emperor Akbar’s court and for blessing him with the birth of his son, Salim (later Emperor Jahangir).

Statement 4 is Correct: The Qadiri Sufi order was one of the oldest in India and was introduced by saints like Sheikh Niamutullah and Makhdum Muhammad Jilani in the Deccant. These saints and orders significantly influenced Indian society by promoting spiritualism, tolerance, and equality.

Explanation

Albedo is the measure of a surface’s reflectivity, with higher albedo indicating greater reflection of sunlight.

Option (b) is correct: The correct sequence in decreasing order of albedo values is Tundra Taiga Tropical Deciduous Tropical Evergreen Tundra (Highest Albedo): Snow and ice dominate the Tundra landscape, leading to the highest reflectivity (albedo). Snow reflects up to 80-90% of sunlight. Taiga (Second Highest Albedo): Taiga, or boreal forests, have a lower albedo than tundra but still reflect sunlight during snowy winters. Dense coniferous forests, combined with snow, lead to moderate albedo values. Tropical Deciduous Forest - Moderate Albedo: These forests shed leaves seasonally, and during the dry season, the exposed ground and sparse canopy increase albedo slightly. Albedo ranges from 15% to 20%. Tropical Evergreen Forest - Low Albedo: Dense, evergreen canopies absorb most sunlight due to year-round leaf cover. Albedo is very low, around 10% to 15%.

Explanation

Ramananda, a 14th-century Bhakti saint, was the first to use Hindi and its dialects to spread devotional teachings, making Bhakti accessible to the common people. He focused on devotion to Lord Rama, rejected caste hierarchies, and advocated equality in worship. His followers, including Kabir, Ravidas, Tulsidas, and Dadu, further popularized Hindi, solidifying Ramananda’s role in using the vernacular for religious reform.

Explanation

The extremist nationalist movement in India (late 19th to early 20th century) was marked by its Swadeshi spirit, emphasizing self-reliance, national education, and rural rejuvenation. A detailed analysis of the statements is as follows:

Statement (a) is incorrect: Aswini Kumar Dutta, a prominent leader during the Swadeshi movement led the agitations of Muslim peasants in Barisal, not Liaquat Hussain. Statements (b), (c) and (d) are correct:

In 1889, the scheme of national education was formulated by Satish Chandra Mukherjee. The Bengal National College was founded in 1906 with Aurobindo as the first Principal, which was established in the context of the Swadeshi movement to promote nationalistic education. Rabindranath Tagore actively advocated for the philosophy of Atmasakti (self-reliance), highlighting the need for the socio-economic development of villages to achieve national progress.

Explanation

Assertion (A) is true: The 60°-65° latitudes in both hemispheres are dominated by the subpolar low-pressure belt, where the cold polar easterlies meet the warm westerlies, creating a zone of convergence. This leads to rising air and low-pressure conditions. Reason (R) is false: While oceans generally have a more stable pressure pattern due to their thermal inertia, low-pressure systems in the subpolar regions are not restricted to oceans and can also occur over land, especially in areas influenced by westerlies and cyclonic activity.