UPSC CISF-AC-EXE Archives

41. The process of degradation of humus by some microorganisms and release

The process of degradation of humus by some microorganisms and release of inorganic nutrients is known as

eutrophication

mineralization

humification

stratification

This question was previously asked in

UPSC CISF-AC-EXE – 2024

Download PDF Attempt Online

The correct answer is B) mineralization.

Mineralization is the process by which organic matter, such as humus, is decomposed by microorganisms into inorganic nutrients (minerals) like nitrates, phosphates, and sulfates. These inorganic nutrients are then available for uptake by plants.

Humification is the process of formation of humus, a stable form of organic matter, from the decomposition of plant and animal residues. Eutrophication is the enrichment of water bodies with nutrients. Stratification refers to the layering of soil or water bodies. Mineralization is a key part of nutrient cycling in ecosystems.

42. Fruit formation from the thalamus instead of ovary is known as false f

Fruit formation from the thalamus instead of ovary is known as false fruit. The most common examples are

orange and mango

mango and banana

apple and strawberry

guava and cherry

This question was previously asked in

UPSC CISF-AC-EXE – 2024

Download PDF Attempt Online

The correct answer is C) apple and strawberry.

A false fruit (or accessory fruit) is one where the fleshy, edible part is developed from tissues other than the ovary, such as the thalamus, petals, or sepals. In apples and strawberries, the edible fleshy part is primarily derived from the receptacle (thalamus).

True fruits develop exclusively from the ovary after fertilization. Examples include mango, orange, tomato, and cherry. Banana is also considered a true fruit, often developing parthenocarpically (without fertilization). Guava is a true fruit.

43. The arrangement and distribution of flowers over a plant is called

The arrangement and distribution of flowers over a plant is called

flowering

inflorescence

thalamus

aestivation

This question was previously asked in

UPSC CISF-AC-EXE – 2024

Download PDF Attempt Online

The correct answer is B) inflorescence.

The arrangement of flowers on the floral axis of a plant is known as inflorescence. This arrangement can vary widely among different plant species (e.g., spike, raceme, panicle, umbel, capitulum).

Flowering is the process of producing flowers. Thalamus (or receptacle) is the part of the flower stalk from which the floral parts arise. Aestivation refers to the arrangement of petals and sepals within a flower bud before it opens.

44. Lichens represent the symbiotic relationships between algae and fungi.

Lichens represent the symbiotic relationships between algae and fungi. The algae component present in lichen is best known as

mycobiont

phycobiont

prion

symbiont

This question was previously asked in

UPSC CISF-AC-EXE – 2024

Download PDF Attempt Online

The correct answer is B) phycobiont.

Lichens are composite organisms resulting from the symbiotic association between a fungus and a photosynthetic partner, usually an alga or cyanobacterium. The fungal component is called the mycobiont, and the photosynthetic algal or cyanobacterial component is called the phycobiont.

In the lichen symbiosis, the fungus typically provides structure, protection, and absorbs water and minerals, while the phycobiont produces food through photosynthesis. This mutualistic relationship allows lichens to survive in harsh environments where neither partner could thrive alone. A prion is a misfolded protein that can cause disease. Symbiont is a general term for an organism involved in a symbiotic relationship.

45. Which of the following are the major contaminants from industries and

Which of the following are the major contaminants from industries and households that cause cultural eutrophication?

Chlorine and aldrin

Mercury and nitrates

Nitrates and phosphates

Phosphates and ammonium

This question was previously asked in

UPSC CISF-AC-EXE – 2024

Download PDF Attempt Online

The correct answer is C) Nitrates and phosphates.

Cultural eutrophication is the process of nutrient enrichment of water bodies by human activities. The major contaminants from industries, agriculture, and households that cause this are compounds of nitrogen (like nitrates) and phosphorus (like phosphates). These nutrients promote excessive growth of algae and aquatic plants.

Sources of nitrates include agricultural runoff (fertilizers), sewage, and atmospheric deposition. Sources of phosphates include detergents (historically), sewage, industrial waste, and agricultural runoff. High concentrations of these nutrients disrupt aquatic ecosystems by leading to algal blooms, oxygen depletion (hypoxia) upon decomposition of dead algae, and loss of biodiversity.

46. Consider the following statements about stem cells : 1. Stem cells h

Consider the following statements about stem cells :

1. Stem cells have the potential for self-renewal via mitotic cell division.
2. In 1908, James Thomas and his colleagues first derived human embryonic stem cells from donated blastocysts through in vitro fertilization.

Which of the statements given above is/are correct?

1 only

2 only

Both 1 and 2

Neither 1 nor 2

This question was previously asked in

UPSC CISF-AC-EXE – 2024

Download PDF Attempt Online

The correct answer is A) 1 only.

Statement 1 is correct: Stem cells possess the unique ability to divide and renew themselves through mitotic cell division, maintaining the stem cell population. Statement 2 is incorrect: Human embryonic stem cells were first successfully derived in 1998 by James Thomson and his colleagues at the University of Wisconsin-Madison, not in 1908 by James Thomas.

Stem cells are undifferentiated cells that can differentiate into specialized cell types and can self-renew. There are different types, including embryonic stem cells (derived from blastocysts) and adult stem cells (found in various tissues). Their discovery and potential applications in regenerative medicine are significant areas of research.

47. Ecotone is a

Ecotone is a

diversified ecosystem

transitional ecosystem

transparent ecosystem

stagnation ecosystem

This question was previously asked in

UPSC CISF-AC-EXE – 2024

Download PDF Attempt Online

The correct answer is B) transitional ecosystem.

An ecotone is defined as a transition zone between two different ecological communities or ecosystems. It contains species characteristic of both bordering ecosystems, and often includes species not found in either.

Ecotones are important ecologically as they often have higher biodiversity (edge effect) than the adjacent ecosystems due to the presence of species from both communities. Examples include the transition between a forest and a grassland, or a riverbank bordering a terrestrial area.

48. What is the length of a simple pendulum, which has a frequency of 0.5

What is the length of a simple pendulum, which has a frequency of 0.5 Hz (take g = 10 m/s²)?

1 m

2 m

1.5 m

3 m

This question was previously asked in

UPSC CISF-AC-EXE – 2024

Download PDF Attempt Online

The correct answer is A) 1 m.

The frequency (f) of a simple pendulum is related to its length (L) and the acceleration due to gravity (g) by the formula: f = 1 / (2π√(L/g)). Rearranging this formula to solve for L gives L = g / (4π²f²). Given f = 0.5 Hz and g = 10 m/s², and using the common approximation π² ≈ 10 when g ≈ 9.8 or 10 m/s², we get L = 10 / (4 * 10 * (0.5)²) = 10 / (40 * 0.25) = 10 / 10 = 1 meter.

The period (T) is the reciprocal of the frequency (T = 1/f = 1/0.5 = 2 seconds). The period formula is T = 2π√(L/g). Squaring both sides gives T² = 4π²(L/g), so L = gT² / (4π²). Using T=2s, g=10m/s², and π²≈10: L = 10 * (2)² / (4 * 10) = 10 * 4 / 40 = 40 / 40 = 1 meter. This confirms the result.

49. Who among the following does not have the power to make an order under

Who among the following does not have the power to make an order under Section 98 of the Code of Criminal Procedure, 1973, for restoration of abducted females ?

District Magistrate

Sub-Divisional Magistrate

Superintendent of Police

Magistrate First Class

This question was previously asked in

UPSC CISF-AC-EXE – 2023

Download PDF Attempt Online

The correct answer is C) Superintendent of Police.

Section 98 of the Code of Criminal Procedure, 1973, empowers a District Magistrate, a Sub-divisional Magistrate, or a Magistrate of the first class to make an order for the immediate restoration of abducted females. The Superintendent of Police is not listed among the authorities who can issue such an order under this specific section.

While the police play a crucial role in investigating cases of abduction and assisting in the recovery of victims, the power to issue a judicial order for restoration under Section 98 CrPC rests specifically with certain classes of Magistrates. Other sections of the CrPC deal with the powers and duties of the police in apprehending suspects and recovering persons.

50. Which one among the following metals is not a ferromagnetic material?

Which one among the following metals is not a ferromagnetic material?

Cobalt

Silver

Iron

Nickel

This question was previously asked in

UPSC CISF-AC-EXE – 2024

Download PDF Attempt Online

The correct answer is B) Silver.

Ferromagnetic materials are substances that are strongly attracted by a magnetic field and can be permanently magnetized. Common examples include Iron (Fe), Cobalt (Co), and Nickel (Ni). Silver (Ag) is a diamagnetic material, meaning it is weakly repelled by a magnetic field.

Materials can be classified based on their magnetic properties as diamagnetic, paramagnetic, or ferromagnetic. Diamagnetic materials have paired electrons and oppose external magnetic fields. Paramagnetic materials have unpaired electrons and are weakly attracted to magnetic fields. Ferromagnetic materials exhibit a strong attraction to magnetic fields due to the alignment of magnetic domains.