41. Which of the following is/are unique characteristic/characteristics of

Which of the following is/are unique characteristic/characteristics of equatorial forests?

  1. Presence of tall, closely set trees with crowns forming a continuous canopy
  2. Coexistence of a large number of species
  3. Presence of numerous varieties of epiphytes

Select the correct answer using the codes given below.

1 only
2 and 3 only
1 and 3 only
1, 2 and 3
This question was previously asked in
UPSC IAS – 2013
All three statements describe characteristic features of equatorial forests (tropical rainforests). The presence of tall, closely set trees with a continuous canopy (leading to stratification), extremely high biodiversity with a large number of coexisting species, and the abundance of epiphytes are all unique or highly pronounced characteristics of this biome compared to others.
Equatorial forests are known for their high temperature and rainfall year-round, leading to dense vegetation, complex vertical structure (canopy layers), and exceptional species richness. These conditions also favour the growth of plants that live on others, like epiphytes.
The multi-layered structure of the forest, from the emergent layer to the understorey and forest floor, is a direct consequence of the dense canopy. The high biodiversity is attributed to a stable climate over long periods and complex ecological interactions. Epiphytes thrive in the humid conditions, utilizing the trees for support and access to sunlight.

42. The most important fishing grounds of the world are found in the regio

The most important fishing grounds of the world are found in the regions where

warm and cold atmospheric currents meet
rivers drain out large amounts of freshwater into the sea
warm and cold oceanic currents meet
continental shelf is undulating
This question was previously asked in
UPSC IAS – 2013
The most important fishing grounds of the world are typically found where warm and cold oceanic currents meet. This is because the meeting of currents causes upwelling, bringing nutrient-rich cold water from the ocean depths to the surface. This nutrient supply supports a large growth of plankton, which forms the base of the marine food web, leading to high populations of fish and other marine life.
The convergence of different oceanic currents, especially warm and cold ones, is a major factor in creating productive marine environments suitable for large-scale fishing. Upwelling associated with these areas is key to nutrient availability.
Examples of major fishing grounds located at the convergence of currents include the Grand Banks off Newfoundland (meeting of the warm Gulf Stream and the cold Labrador Current) and the North Sea (meeting of the North Atlantic Drift and polar waters). The continental shelf is also important because it is shallow enough for sunlight penetration, supporting photosynthesis, but the current mixing provides the significant boost in productivity.

43. With reference to the food chains in ecosystems, which of the followin

With reference to the food chains in ecosystems, which of the following kinds of organism is/are known as decomposer organism/organisms?

  1. Virus
  2. Fungi
  3. Bacteria

Select the correct answer using the codes given below.

1 only
2 and 3 only
1 and 3 only
1, 2 and 3
This question was previously asked in
UPSC IAS – 2013
Fungi and Bacteria are the primary decomposers in most ecosystems. They break down dead organic matter, returning nutrients to the environment. Viruses are not decomposers; they are parasitic and reproduce within host cells.
Decomposers are organisms that break down dead or decaying organisms, and in doing so, they carry out the natural process of decomposition. They play a vital role in nutrient cycling, making essential nutrients available to producers (plants).
Decomposition is a critical part of the food web. While fungi and bacteria are the main decomposers, detritivores (like earthworms, beetles, and millipedes) also contribute by physically breaking down organic matter, which increases the surface area for fungi and bacteria to act upon.

44. Consider the following Bhakti Saints : Dadu Dayal Guru Nanak Tya

Consider the following Bhakti Saints :

  1. Dadu Dayal
  2. Guru Nanak
  3. Tyagaraja

Who among the above was/were preaching when the Lodi dynasty fell and Babur took over?

1 and 3
2 only
2 and 3
1 and 2
This question was previously asked in
UPSC IAS – 2013
Guru Nanak (1469-1539) lived during the period when the Lodi dynasty ruled Delhi and was succeeded by Babur in 1526. Dadu Dayal (1544-1603) and Tyagaraja (1767-1847) lived much later. Therefore, only Guru Nanak was preaching during the transition from the Lodi dynasty to Babur’s rule.
This question tests knowledge of the timeline of prominent Bhakti saints and their contemporaries among ruling dynasties. Identifying the lifespans of the saints is crucial to determine who was active during the specified historical period (fall of Lodi dynasty and rise of Babur, i.e., around 1526).
Guru Nanak, the founder of Sikhism, travelled widely during his lifetime and preached a message of equality, devotion to one God, and rejection of ritualism. The Lodi dynasty ruled from 1451 to 1526. Babur defeated Ibrahim Lodi in the First Battle of Panipat in 1526, marking the beginning of the Mughal Empire in India.

45. Consider the following statements: The Parliamentary Committee on Pu

Consider the following statements:

  • The Parliamentary Committee on Public Accounts
  • 1. consists of not more than 25 Members of the Lok Sabha
  • 2. scrutinizes appropriation and finance accounts of the Government
  • 3. examines the report of the Comptroller and Auditor General of India

Which of the statements given above is/are correct?

1 only
2 and 3 only
3 only
1, 2 and 3
This question was previously asked in
UPSC IAS – 2013
Statements 2 and 3 are correct. The Parliamentary Committee on Public Accounts examines the appropriation and finance accounts of the Government and scrutinizes the reports of the Comptroller and Auditor General of India (CAG). Statement 1 is incorrect as the committee consists of 22 members, not 25.
The Public Accounts Committee (PAC) is the oldest financial committee of the Indian Parliament. Its primary function is to examine the accounts showing the appropriation of sums granted by Parliament for expenditure and the annual finance accounts of the Union government, particularly focusing on the reports of the CAG.
The PAC consists of 22 members – 15 elected by the Lok Sabha from amongst its members and 7 elected by the Rajya Sabha from amongst its members by means of the single transferable vote. The term of office is one year. The Chairman of the committee is appointed by the Speaker of the Lok Sabha and is traditionally from the opposition party.

46. Consider the following minerals : 1. Calcium 2. Iron 3. Sodium Wh

Consider the following minerals :

  • 1. Calcium
  • 2. Iron
  • 3. Sodium

Which of the minerals given above is/are required by human body for the contraction of muscles?

1 only
2 and 3 only
1 and 3 only
1, 2 and 3
This question was previously asked in
UPSC IAS – 2013
Calcium and Sodium are minerals required by the human body for the contraction of muscles.
– **Calcium:** Calcium ions (Ca²⁺) are essential for initiating muscle contraction. In skeletal muscle, the release of calcium from the sarcoplasmic reticulum triggers the binding of myosin to actin filaments, leading to the sliding filament mechanism of contraction.
– **Sodium:** Sodium ions (Na⁺) play a critical role in the electrical signaling that initiates muscle contraction. An action potential, involving the influx of sodium ions across the muscle cell membrane, causes depolarization, which in turn leads to the release of calcium ions. Potassium ions (K⁺) are also crucial for repolarization and maintaining the membrane potential.
– **Iron:** Iron is vital for overall muscle function, primarily because it is a component of myoglobin, which stores oxygen in muscle cells, and enzymes involved in energy metabolism. However, it is not directly involved in the biochemical process of muscle fiber contraction itself in the same way calcium and sodium are.
Muscle contraction is a complex physiological process involving nerve impulses, changes in membrane potential, release of neurotransmitters, and the interaction of contractile proteins (actin and myosin) mediated by calcium ions. Electrolytes like sodium, potassium, calcium, and magnesium are all important for proper muscle and nerve function.

47. Photochemical smog is a resultant of the reaction among

Photochemical smog is a resultant of the reaction among

NO₂, O₃ and peroxyacetyl nitrate in the presence of sunlight
CO, O₂ and peroxyacetyl nitrate in the presence of sunlight
CO, CO₂ and NO₂ at low temperature
high concentration of NO₂, O₃ and CO in the evening
This question was previously asked in
UPSC IAS – 2013
Photochemical smog is a complex mixture of air pollutants that forms when sunlight reacts with certain chemicals in the atmosphere. Key components and precursors include nitrogen oxides (NOx) and volatile organic compounds (VOCs). The resulting smog contains pollutants like ozone (O₃), peroxyacetyl nitrate (PAN), and aldehydes.
The formation of photochemical smog is driven by sunlight. Nitrogen dioxide (NO₂) is a primary pollutant that photodissociates in sunlight to form nitric oxide (NO) and atomic oxygen (O). This atomic oxygen quickly reacts with molecular oxygen (O₂) to form ozone (O₃). VOCs react with NOx and other atmospheric components in the presence of sunlight to form a variety of secondary pollutants, including PAN. Therefore, NO₂, O₃ (as a product), and PAN (as a product), with sunlight as the driving force, are central to photochemical smog.
Photochemical smog is often referred to as “Los Angeles smog” because it was first recognized in Los Angeles. It differs from traditional “London smog” (sulfurous smog), which is caused by the burning of fossil fuels containing sulfur and occurs under cool, humid conditions. Photochemical smog is more common in sunny, dry climates with significant vehicular traffic.

48. Which one of the following terms describes not only the physical space

Which one of the following terms describes not only the physical space occupied by an organism, but also its functional role in the community of organisms?

Ecotone
Ecological niche
Habitat
Home range
This question was previously asked in
UPSC IAS – 2013
The term that describes both the physical space occupied by an organism and its functional role in the community is “Ecological niche”.
– **Habitat:** Refers primarily to the physical environment or location where an organism lives.
– **Ecotone:** Is a transition zone between two different ecosystems.
– **Home range:** Is the area an animal traverses in its activities, but it doesn’t define its functional role.
– **Ecological niche:** Encompasses not just the physical space (like habitat) but also the organism’s role, including how it interacts with other organisms (predators, prey, competitors), what it consumes, how it reproduces, and how it is affected by its environment. It is often described as the organism’s “profession” or “address + profession” within the ecosystem.
The concept of the ecological niche was first described by Joseph Grinnell (focused on habitat) and later refined by Charles Elton (focused on the functional role) and G. Evelyn Hutchinson (mathematical definition of the ‘n-dimensional hypervolume’). The principle of competitive exclusion states that no two species can occupy exactly the same niche in the same habitat for a prolonged period.

49. Which of the following statements is/are applicable to Jain doctrine?

Which of the following statements is/are applicable to Jain doctrine?

  • 1. The surest way of annihilating Karma is to practice penance.
  • 2. Every object, even the smallest particle has a soul.
  • 3. Karma is the bane of the soul and must be ended.

Select the correct answer using the codes given below.

1 only
2 and 3 only
1 and 3 only
1, 2 and 3
This question was previously asked in
UPSC IAS – 2013
All three statements are applicable to Jain doctrine.
1. **Penance (Tapas):** Jainism strongly emphasizes ascetic practices and penance as a means to burn off accumulated Karma and attain liberation. It is considered essential for purifying the soul and annihilating Karmic matter.
2. **Soul in every object:** Jain philosophy believes that souls (Jiva) exist not only in humans and animals but also in plants, water bodies, air, and even subtle particles (nigodas). This belief underlies the principle of Ahimsa (non-violence) towards all forms of life.
3. **Karma as bane of the soul:** Jainism views Karma as subtle matter that attaches to the soul, binding it to the cycle of birth, death, and suffering (samsara). The ultimate goal is to shed all Karmic matter to achieve Moksha (liberation) and attain the soul’s pure state of infinite knowledge, perception, bliss, and energy.
Key principles of Jainism include Ahimsa (non-violence), Satya (truthfulness), Asteya (non-stealing), Brahmacharya (celibacy/chastity), and Aparigraha (non-possession). The path to liberation involves following the three jewels (Triratna): Right Faith (Samyak Darshan), Right Knowledge (Samyak Gyan), and Right Conduct (Samyak Charitra).

50. Which of the following diseases can be transmitted from one person to

Which of the following diseases can be transmitted from one person to another through tattooing?

  • 1. Chikungunya
  • 2. Hepatitis B
  • 3. HIV-AIDS

Select the correct answer using the codes given below.

1 only
2 and 3 only
1 and 3 only
1, 2 and 3
This question was previously asked in
UPSC IAS – 2013
Hepatitis B and HIV-AIDS can be transmitted from one person to another through tattooing if contaminated equipment is used.
Tattooing involves piercing the skin. If needles or other instruments used for tattooing are not properly sterilized and have been contaminated with infected blood, blood-borne viruses can be transmitted.
1. Chikungunya is a viral disease transmitted by mosquitoes, not through blood-to-blood contact via needles.
2. Hepatitis B is a blood-borne virus that can be transmitted through contaminated needles, syringes, or other sharp instruments.
3. HIV-AIDS is caused by the Human Immunodeficiency Virus (HIV), which is primarily transmitted through blood, semen, vaginal fluids, and breast milk. Sharing contaminated needles is a known risk factor for HIV transmission.
Other infections that can potentially be transmitted through unsterile tattooing practices include Hepatitis C, tetanus, and various bacterial infections. Proper sterilization techniques and single-use needles are crucial for preventing the spread of diseases during tattooing.