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Question 2561Question →

Arrange the following stages of primary xerarch (lithosere) ecological succession on a bare rock substrate in the correct chronological sequence of community development, from the initial pioneer stage to the final climax stage:

Drag items to arrange them in the correct order

Show answer & explanation

Answer

The correct chronological sequence of primary xerarch (lithosere) succession on a bare rock is: Crustose Lichen Stage → Foliose Lichen Stage → Moss Stage → Herbaceous Grass Stage → Climax Forest Stage.
Primary lithosere succession is autogenic and progressive, driven by microenvironmental modification of bare rock. Crustose lichens initially weather rock minerals and trap organic dust. Foliose lichens build upon this substrate, creating conditions suitable for xerophytic mosses. The accumulating moss mat provides enough soil depth for vascular grasses, which eventually yield to shrubs and a stable, self-perpetuating mesophytic climax forest.

Step-by-Step Solution

1
Identify the pioneer community capable of colonizing bare, unweathered rock.
Crustose lichens are the pioneer organisms because they survive extreme desiccation and produce acidic exudates that initiate micro-weathering of minerals.
Primary succession on rock must begin with organisms that do not require pre-existing soil.
2
Determine the succeeding lichen form that replaces crustose lichens.
Foliose and fruticose lichens override crustose lichens once minimal wind-borne dust and weathered rock particles collect beneath their thalli.
Foliose lichens have larger leaf-like thalli that shade out crustose lichens and accumulate more organic particles.
3
Trace the transition from lichen-dominated substrate to bryophytes.
Xerophytic mosses establish in the fine soil accumulated by foliose lichens.
Mosses have rhizoids that hold soil together and accumulate significantly more organic matter and moisture than lichens.
4
Identify the stage where true vascular herbaceous vegetation invades.
Annual and perennial grasses colonize as the soil substrate thickens and retains sufficient moisture.
Vascular plant roots penetrate deeper, binding soil particles and enriching substrate nitrogen and humus through root turnover.
5
Identify the ultimate equilibrium stage of community succession.
Woody shrubs pave the way for shade-tolerant, tall trees forming a stable mesophytic climax forest.
The mature soil layer reaches sufficient depth and fertility to support deep-rooted, long-lived arboreal species adapted to ambient climatic conditions.

Key Concept

Primary Xerarch (Lithosere) Ecological Succession Stages
Question 2562Question →

With reference to transgenic Bt (*Bacillus thuringiensis*) technology used in agricultural crop protection, consider the following statements:

1. The crystalline insecticidal proteins produced by *Bacillus thuringiensis* are inactive protoxins that require the alkaline pH environment of the insect midgut for solubilization and activation.
2. Transgenic crops expressing *Cry1Ac* genes provide broad-spectrum protection primarily against sap-sucking insect pests such as aphids and whiteflies.
3. The mandatory planting of non-Bt 'refuge' crops surrounding Bt crop fields is an agronomic management strategy intended to delay the development of insect resistance to Bt toxins.

Which of the statements given above is/are correct?

Show answer & explanation

Answer: 1 and 3 only

Answer

1 and 3 only
The correct response identifies statements 1 and 3 as true. The Bt crystal protoxin requires an alkaline midgut pH for conversion into an active toxin that disrupts gut cell membrane integrity. Furthermore, non-Bt refuge planting is a established IPM strategy designed to preserve susceptible alleles within target pest populations, slowing down natural selection for resistance.

Step-by-Step Solution

1
Analyze Statement 1 regarding the mechanism of action of Bt endotoxins.
Bt bacteria produce inactive crystal proteins (protoxins). Upon ingestion by susceptible insects, these protoxins are solubilized in the alkaline environment of the insect midgut and cleaved by proteases into active toxins, which bind to midgut epithelial cells and create pores. Thus, statement 1 is correct.
Understanding the biochemical trigger for Bt toxin activation is essential for evaluating plant biotechnology applications.
2
Analyze Statement 2 regarding the target pest spectrum of Cry1Ac gene products.
The Cry1Ac gene specifically encodes toxins active against lepidopteran pests (such as the American bollworm, Pink bollworm, and tobacco budworm). Sucking pests (order Hemiptera, such as aphids, jassids, and whiteflies) are not susceptible to Cry1Ac toxins. Thus, statement 2 is incorrect.
Distinguishing between pest orders and their specific susceptibility to Cry protein sub-classes is key to agronomic crop protection analysis.
3
Analyze Statement 3 regarding the agronomic purpose of refuge crop strategies.
Planting non-Bt refuge crops ensures a localized population of susceptible insects that mate with any rare homozygous resistant insects emerging from Bt fields. This dilutes resistance genes in the pest population and significantly delays resistance development. Thus, statement 3 is correct.
Insect resistance management (IRM) strategies are vital components of sustainable agricultural biotechnology policy.

Key Concept

Bt Transgenic Technology and Insect Resistance Management
Question 2563Question →

Consider the following statements regarding Biodiversity Hotspots and Endemism in India:

1. To qualify as a biodiversity hotspot under Norman Myers' criteria, a region must contain at least 1,500 species of endemic vascular plants and must have lost at least 70% of its primary vegetation.
2. The Western Ghats region hosts endemic fauna such as the Lion-tailed Macaque (*Macaca silenus*) and the Nilgiri Tahr (*Nilgiritragus hylocrius*).
3. Geographically, the Andaman group of islands falls within the Indo-Burma biodiversity hotspot, whereas the Nicobar group of islands is included under the Sundaland biodiversity hotspot.

Which of the statements given above are correct?

Show answer & explanation

Answer: 1, 2 and 3

Answer

All three statements (1, 2, and 3) are correct.
The correct answer includes all three statements because Norman Myers' quantitative criteria mandate 1,500 endemic vascular plant species and at least 70% loss of primary vegetation, the Western Ghats harbors endemic species like the Lion-tailed Macaque and Nilgiri Tahr, and the Andaman and Nicobar Islands are split biogeographically between the Indo-Burma and Sundaland hotspots respectively.

Step-by-Step Solution

1
Evaluate Statement 1 regarding hotspot qualification criteria.
Statement 1 is correct. According to Conservation International and Norman Myers, a region must meet two strict quantitative threshold criteria: (a) it must contain at least 1,500 species of endemic vascular plants (>0.5% of the world total), and (b) it must have lost at least 70% of its primary native vegetation (retaining 30% or less of its original natural habitat).
Quantitative thresholds ensure standardized global hotspot identification.
2
Evaluate Statement 2 regarding endemic species of the Western Ghats.
Statement 2 is correct. The Western Ghats is an endemic-rich biodiversity hotspot featuring habitat-restricted flagship species such as the Lion-tailed Macaque (*Macaca silenus*) and the Nilgiri Tahr (*Nilgiritragus hylocrius*).
High levels of endemism define the conservation priority of this biome.
3
Evaluate Statement 3 regarding regional delineation of Indian hotspots.
Statement 3 is correct. India features four recognized biodiversity hotspot regions. Biogeographically, the Andaman island chain forms part of the Indo-Burma hotspot, while the Nicobar island chain is part of the Sundaland hotspot.
Island archipelagos in eastern India span distinct biogeographical realm transitions.

Key Concept

Biodiversity Hotspot Criteria, Endemic Species, and Regional Delineation of Indian Hotspots
Question 2564Question →

Which of the following statements regarding a Proclamation of Financial Emergency under Article 360 of the Constitution of India are correct?

Select all that apply

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Answer: A proclamation of Financial Emergency must be approved by both Houses of Parliament within two months from the date of its issue.; During the period of Financial Emergency, the President may issue directions requiring all Money Bills passed by a state legislature to be reserved for presidential consideration.; Once approved by both Houses of Parliament, the Financial Emergency continues indefinitely until it is revoked by the President, without requiring periodic parliamentary approval.

Answer

The correct statements are that a proclamation of Financial Emergency must be approved within two months by both Houses of Parliament, state Money Bills can be directed to be reserved for the President's consideration, and once approved, the emergency continues indefinitely until revoked without needing periodic parliamentary re-approval.
Under Article 360 of the Indian Constitution, a Financial Emergency must be approved by both Houses of Parliament within two months by a simple majority. During its operation, the Centre can direct states to observe financial discipline, including reserving Money Bills for the President's approval. Furthermore, once approved by Parliament, a Financial Emergency remains in force indefinitely until revoked by the President, with no requirement for periodic extensions.

Step-by-Step Solution

1
Analyze the parliamentary approval timeframe for Article 360.
Article 360(2) specifies a two-month timeframe for approval by both Houses of Parliament from the date of issuance.
Establishing the constitutional timeline for parliamentary ratification of a Financial Emergency.
2
Examine the executive powers of the Union over state financial legislation during a Financial Emergency.
Under Article 360(4)(a)(ii), the Union can direct that Money Bills passed by state legislatures be reserved for the President.
Verifying Union legislative control over state finances during financial crises.
3
Evaluate the majority threshold required for passing the approval resolution.
Article 360 requires a simple majority (majority of members present and voting) in each House, not a special majority.
Distinguishing parliamentary voting requirements of Article 360 from Article 352.
4
Verify the duration and periodic renewal requirements for Financial Emergency.
Once ratified by Parliament, a Financial Emergency continues indefinitely until revoked by the President, with no requirement for 6-month periodic extensions.
Understanding the temporal limits and continuation procedures under Article 360.

Key Concept

Constitutional provisions, parliamentary approval rules, and executive effects of Financial Emergency under Article 360
Estimated Time:1m 30s
Question 2565Question →

Consider the following statements regarding global biodiversity hotspots that encompass regions of India:

1. The Western Ghats region is designated as one of the global biodiversity hotspots.
2. The entire Indo-Gangetic Plain is classified as a global biodiversity hotspot owing to high agricultural crop diversity.

Which of the statements given above is/are correct?

Show answer & explanation

Answer: 1 only

Answer

The statement asserting that the Western Ghats region is designated as a global biodiversity hotspot is correct, whereas the statement regarding the Indo-Gangetic Plain is incorrect.
The correct response identifies that only the first statement is factual. India features four recognized biodiversity hotspots: the Western Ghats, the Himalayas, Indo-Burma, and Sundaland (Nicobar Islands). The Indo-Gangetic Plain is an agricultural belt and not a designated global biodiversity hotspot.

Step-by-Step Solution

1
Evaluate Statement 1 regarding the Western Ghats.
Statement 1 is correct.
The Western Ghats (along with Sri Lanka) is one of the four biodiversity hotspots present in/around India, possessing high species endemism and facing severe habitat degradation.
2
Evaluate Statement 2 regarding the Indo-Gangetic Plain.
Statement 2 is incorrect.
Global biodiversity hotspots require exceptional levels of plant endemism (at least 1,500 endemic vascular plant species) and high habitat loss (at least 70% lost). Agricultural landscapes like the Indo-Gangetic Plain do not fulfill these criteria.

Key Concept

Indian Biodiversity Hotspots
Estimated Time:45s
Question 2566Question →

Match the inflation types and phenomena listed in List-I with their corresponding economic characteristics listed in List-II.

Click a left item, then click its matching right item

Items

Shrinkflation
Skewflation
Headline Inflation
Core Inflation

Matches

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Answer

Shrinkflation matches with the reduction of product quantity at constant retail price; Skewflation matches with price rise concentrated in a specific group of commodities; Headline Inflation matches with total inflation including food and fuel; and Core Inflation matches with persistent inflation excluding food and fuel.
Shrinkflation is characterized by hidden price increases where packaging size drops while retail price stays fixed. Skewflation describes price inflation concentrated within limited specific items like food products. Headline Inflation represents total price variation across the entire representative consumer basket. Core Inflation excludes volatile components such as food and energy to reflect long-term underlying inflationary trends.

Step-by-Step Solution

1
Identify the characteristic of Shrinkflation
Shrinkflation corresponds to maintaining the price sticker while reducing volume, weight, or count of the product.
Firms use this subtle cost-pass-through method when input costs rise without triggering consumer price resistance.
2
Identify the characteristic of Skewflation
Skewflation denotes price increases concentrated within one or a few sectors while prices in other sectors remain moderate or flat.
It highlights sectoral supply bottlenecks rather than generalized monetary expansion.
3
Distinguish between Headline Inflation and Core Inflation
Headline inflation evaluates the entire consumer price index basket, whereas Core inflation filters out volatile food and fuel items.
Excluding temporary supply-side price spikes in food and fuel reveals persistent macroeconomic monetary pressure.

Key Concept

Inflation Types, Price Indices, and Structural Inflationary Dynamics
Question 2567Question →

Consider the following statements regarding the Estimates Committee of the Indian Parliament:

1. It consists of 30 members, all of whom are drawn exclusively from the Lok Sabha.
2. A Minister can be elected as a member of this committee provided the Speaker approves.
3. By parliamentary convention, the Chairman of the committee is appointed from amongst the members belonging to the ruling party.

Which of the statements given above are correct?

Show answer & explanation

Answer: 1 and 3 only

Answer

Statements 1 and 3 are correct.
The correct response identifies that statements 1 and 3 are accurate. The Estimates Committee is the largest parliamentary committee, consisting of 30 members elected solely from the Lok Sabha (Rajya Sabha has zero representation). Ministers are excluded from election to ensure legislative independence over executive financial estimates. Furthermore, by political convention, the Speaker appoints a Chairman belonging to the ruling party, unlike the Public Accounts Committee whose Chairman is customarily from the opposition.

Step-by-Step Solution

1
Analyze Statement 1 regarding the membership structure of the Estimates Committee.
The Estimates Committee has 30 members, and all 30 are elected from the Lok Sabha every year from amongst its members according to the principle of proportional representation by means of a single transferable vote. Rajya Sabha has no representation in this committee.
This establishes that Statement 1 is correct.
2
Analyze Statement 2 regarding minister eligibility for committee membership.
A Minister cannot be elected as a member of the Estimates Committee. If a member, after election to the committee, becomes a Minister, he or she ceases to be a member of the committee from the date of such appointment.
This proves Statement 2 is incorrect.
3
Analyze Statement 3 regarding the convention of appointing the Chairman of the Estimates Committee.
The Chairman of the Estimates Committee is appointed by the Speaker from amongst its members. By established convention, the Chairman is invariably selected from the ruling party/coalition.
This confirms Statement 3 is correct.

Key Concept

Structure, membership rules, and chairmanship conventions of Parliamentary Financial Committees (Estimates Committee)
Question 2568Question →

With reference to ecosystem functions and nutrient cycling, consider the following statements:

1. Gaseous cycles generally have their primary reservoir pool located in the Earth's crust, whereas sedimentary cycles have their main reservoir pool in the atmosphere or hydrosphere.
2. Nitrifying bacteria such as *Nitrosomonas* and *Nitrobacter* convert ammonia into nitrites and nitrates during the nitrogen cycle.
3. The pyramid of energy is always upright in any functional ecosystem because energy is lost as heat at each successive trophic level.

Which of the statements given above are correct?

Show answer & explanation

Answer: 2 and 3 only

Answer

Statements 2 and 3 are correct.
Statement 2 accurately describes the process of nitrification carried out by nitrifying bacteria (*Nitrosomonas* and *Nitrobacter*). Statement 3 accurately describes why the pyramid of energy is always upright in functional ecosystems due to progressive energy loss across trophic levels. Statement 1 is incorrect because the reservoir pool for gaseous cycles is the atmosphere or hydrosphere, whereas for sedimentary cycles, it is the lithosphere (Earth's crust). Therefore, the correct combination includes only statements 2 and 3.

Step-by-Step Solution

1
Analyze statement 1 regarding biogeochemical reservoir pools.
Gaseous nutrient cycles (e.g., carbon, nitrogen) have their main reservoir pool in the atmosphere or hydrosphere. Sedimentary cycles (e.g., phosphorus, sulfur) have their primary reservoir pool in the lithosphere (Earth's crust/rocks). Statement 1 incorrectly swaps these definitions.
To evaluate the correct reservoir pool classifications.
2
Analyze statement 2 regarding nitrogen transformation.
Nitrification is a two-step biological oxidation process where *Nitrosomonas* converts ammonia into nitrite (NO2−NO_2^-) and *Nitrobacter* converts nitrite into nitrate (NO3−NO_3^-). Thus, statement 2 is correct.
To verify the roles of specific microbial organisms in the nitrogen cycle.
3
Analyze statement 3 regarding ecological pyramids.
Energy flows unidirectionally and diminishes at higher trophic levels (governed by the 10% law of energy transfer), making the pyramid of energy universally upright in all ecosystems without exception. Statement 3 is correct.
To confirm thermodynamic principles governing energy flow.

Key Concept

Classification of Biogeochemical Cycles and Trophic Energy Flow
Estimated Time:1m 15s
Question 2569Question →

With reference to recent developments in Biotechnology and Nanotechnology, consider the following statements:

1. Quantum dots are semiconductor nanocrystals whose fluorescence wavelength decreases as the particle size increases.
2. Somatic Cell Nuclear Transfer (SCNT) produces embryonic stem cells that inherit nuclear genomic DNA primarily from the somatic cell donor rather than the egg donor.
3. Carbon nanotubes can display either metallic or semiconducting electrical conductivity depending on their chiral angle and diameter.

Which of the statements given above is/are correct?

Show answer & explanation

Answer: 2 and 3 only

Answer

Statements 2 and 3 are correct, while Statement 1 is incorrect.
The option stating '2 and 3 only' is correct because Statement 2 accurately describes how SCNT transfers nuclear DNA from the somatic cell donor, and Statement 3 accurately describes chirality-governed electrical properties of carbon nanotubes. Statement 1 is false because larger quantum dots emit longer wavelengths (red-shift), not shorter wavelengths.

Step-by-Step Solution

1
Analyze Statement 1 regarding Quantum Dots and optical emission.
Statement 1 is incorrect. In quantum dots, confinement effects broaden the band gap as particle size decreases. Smaller dots emit higher-energy, shorter-wavelength light (blue light), whereas larger dots emit lower-energy, longer-wavelength light (red light).
Quantum confinement correlates bandgap energy inversely with nanoparticle size.
2
Analyze Statement 2 regarding Somatic Cell Nuclear Transfer (SCNT).
Statement 2 is correct. SCNT transfers a somatic nucleus into an enucleated oocyte, making the nuclear DNA virtually identical to the somatic donor cell.
The recipient egg cell contributes only cytoplasm and mitochondrial DNA, while the nuclear gene payload originates entirely from the somatic donor.
3
Analyze Statement 3 regarding Carbon Nanotubes (CNTs).
Statement 3 is correct. The orientation of the graphene roll (chirality vector (n,m)(n, m)) determines whether a single-walled carbon nanotube is metallic or semiconducting.
When (n−m)(n - m) is a multiple of 3, the CNT exhibits metallic conductivity; otherwise, it behaves as a semiconductor.

Key Concept

Quantum confinement in quantum dots, nuclear donor inheritance in SCNT, and chirality-dependent conductivity of carbon nanotubes
Question 2570Question →

Match the everyday physical observations in List-I with their primary underlying physics principles in List-II:

Click a left item, then click its matching right item

Items

Cooling of water stored in an earthen pot
Vacuum space in a double-walled thermos flask
Occurrence of land breeze during nighttime in coastal areas
Loosening a tight metal jar lid by running hot water over it

Matches

Show answer & explanation

Answer

Cooling of water in an earthen pot matches with absorption of latent heat during porous surface evaporation; Vacuum space in a double-walled thermos flask matches with prevention of heat transfer mechanisms that require a material medium; Occurrence of land breeze matches with convective circulation driven by differential specific heat capacities; Loosening a tight metal jar lid matches with differential expansion rates of distinct solid materials upon heating.
Each everyday observation corresponds directly to a fundamental law of thermal physics: earthen pot cooling functions via latent heat of vaporization during evaporation; a thermos vacuum jacket blocks medium-dependent heat transfer (conduction and convection); land breezes are thermal convection currents caused by specific heat differences between land and water; and loosening a glass jar lid utilizes the higher coefficient of thermal expansion of metals compared to glass.

Step-by-Step Solution

1
Analyze the cooling mechanism in an earthen pot.
Microscopic pores facilitate surface evaporation. The phase change consumes thermal energy in the form of latent heat of vaporization from the stored liquid.
Evaporative cooling directly relies on latent heat absorption from the remaining liquid.
2
Examine the role of a vacuum gap in thermal insulation.
Conduction and convection mandate atomic or molecular collisions within a medium. A vacuum evacuates matter, blocking both heat transfer paths.
Thermal energy cannot conduct or convect without physical particles.
3
Evaluate the thermal dynamics driving coastal land breezes.
Because land has a lower specific heat capacity than ocean water, land loses heat faster at night. The resulting temperature difference induces density changes and convective air circulation.
Differential cooling rates establish local atmospheric pressure gradients.
4
Determine the principle behind thermal opening of glass jars.
When exposed to hot water, both the metal lid and glass container absorb heat, but the metal lid expands to a greater degree due to its higher thermal expansion coefficient.
Different materials expand at distinct rates per unit of temperature increase.

Key Concept

Thermal energy transfer mechanisms, latent heat, specific heat capacity, and thermal expansion in daily applications.
Estimated Time:1m 30s
Question 2571Question →

With reference to modern biotechnology, consider the following statements regarding CRISPR-Cas9 technology:

1. It functions as a precise genome-editing tool in living organisms.
2. The Cas9 enzyme acts as molecular scissors to cut target DNA sequences.

Which of the statements given above is/are correct?

Show answer & explanation

Answer: Both 1 and 2

Answer

Both statements 1 and 2 are correct.
Both statements are correct. CRISPR-Cas9 is a major biotechnological advancement adapted from bacterial immune systems. Guide RNA leads the complex to a complementary target sequence on the DNA strand, and the Cas9 enzyme acts as molecular scissors to cut the DNA, enabling precise genomic modifications.

Step-by-Step Solution

1
Evaluate Statement 1 regarding the application of CRISPR-Cas9.
Statement 1 is correct because CRISPR-Cas9 is widely used as a gene-editing technology to add, remove, or alter genetic material in organisms.
CRISPR enables precise modification of DNA sequences within genomes.
2
Evaluate Statement 2 regarding the specific role of the Cas9 component.
Statement 2 is correct because Cas9 is an endonuclease protein that cuts double-stranded DNA at targeted sites specified by guide RNA.
The endonuclease activity of Cas9 functions analogously to molecular scissors.

Key Concept

CRISPR-Cas9 Genome Editing Mechanism
Estimated Time:45s
Question 2572Question →

Regarding the Charter Act of 1833 passed by the British Parliament during colonial rule in India, which of the following provisions are correct?

Select all that apply

Show answer & explanation

Answer: It elevated the Governor-General of Bengal to the Governor-General of India, centralizing all civil, military, and legislative powers for British India under his council.; It ended all remaining commercial activities of the East India Company, converting it into a purely administrative body holding Indian territories in trust for the British Crown.

Answer

The correct provisions are the designation of the Governor-General of Bengal as the Governor-General of India with centralized legislative powers, and the complete termination of the East India Company's commercial activities to make it a purely administrative body.
The Charter Act of 1833 marked a decisive step toward administrative centralization in British India. It elevated the Governor-General of Bengal to the Governor-General of India, conferring upon him full civil, military, and legislative jurisdiction over all British territories while depriving provincial governors of independent lawmaking. Additionally, it stripped the East India Company of its commercial character entirely, turning it into a purely administrative organ managing Indian territories in trust for the British Sovereign.

Step-by-Step Solution

1
Analyze administrative and legislative centralization provisions under colonial charters
The Charter Act of 1833 created the post of Governor-General of India (Lord William Bentinck being the first) and centralized all legislative powers for British India, stripping Bombay and Madras of legislative authority.
Comprehensive legislative centralization was the primary structural reform of the 1833 Act.
2
Evaluate the commercial status of the East India Company after 1833
The Act terminated the company's remaining commercial privileges (tea trade and China trade), transforming it into a purely administrative trustee body for the Crown.
While the 1813 Charter removed most commercial monopolies, the 1833 Charter ended the remaining ones.
3
Identify misattributed features from subsequent constitutional acts
The creation of a distinct legislative council occurred under the Charter Act of 1853, while separate electorates were established under the Indian Councils Act of 1909.
Distinguishing the specific contributions of sequential colonial legislations prevents misattribution errors.

Key Concept

Charter Act of 1833 Provisions and Administrative Centralization
Estimated Time:1m 0s
Question 2573Question →

Consider the following statements regarding Public Key Infrastructure (PKI) and digital signature mechanisms:

1. A digital signature ensures non-repudiation and data integrity, but it does not inherently provide message confidentiality.
2. The Online Certificate Status Protocol (OCSP) allows real-time verification of a digital certificate's revocation status without requiring the download of complete Certificate Revocation Lists (CRLs).
3. In asymmetric cryptography, a sender encrypts a message with their own private key to ensure confidentiality for the intended recipient.

Which of the statements given above is/are correct?

Show answer & explanation

Answer: 1 and 2 only

Answer

The statements asserting that digital signatures provide non-repudiation and integrity without inherent confidentiality (Statement 1) and that OCSP enables real-time certificate status verification compared to CRLs (Statement 2) are correct. The statement regarding private key encryption for confidentiality (Statement 3) is incorrect.
Statements 1 and 2 are accurate. A digital signature verifies origin and prevents tampering but does not hide the content from third parties. OCSP provides live, real-time revocation checks per certificate, improving on CRL download overhead. Statement 3 is wrong because recipient confidentiality requires encryption using the recipient's public key.

Step-by-Step Solution

1
Analyze Statement 1 regarding digital signature security services.
Digital signatures are created by hashing data and encrypting the hash with the sender's private key. This guarantees integrity and non-repudiation. However, the plaintext payload remains unencrypted unless symmetric/asymmetric encryption is added.
Verify if confidentiality is an inherent property of digital signatures.
2
Analyze Statement 2 regarding PKI certificate revocation protocols.
CRL requires downloading complete, potentially large lists of revoked certificates periodically. OCSP sends a lightweight request for a single certificate status directly to an OCSP responder in real time, making it faster and less bandwidth-intensive.
Compare CRL and OCSP certificate revocation checking mechanisms.
3
Analyze Statement 3 regarding asymmetric key cryptography for confidentiality.
To achieve confidentiality, data must be encrypted using the recipient's public key, ensuring only the recipient holding the corresponding private key can decrypt it. Encrypting with a sender's private key provides authentication/signature, not confidentiality.
Identify the proper key selection for message encryption.

Key Concept

Public Key Infrastructure, Asymmetric Cryptography Key Usage, and Certificate Revocation Protocols
Question 2574Question →

In public health and epidemiology, infectious human diseases are categorized by the biological nature of their causative agents to determine appropriate clinical treatments and preventive measures. Which of the following human diseases is caused by a bacterial pathogen?

Show answer & explanation

Answer: Diphtheria

Answer

Diphtheria is caused by a bacterial pathogen (Corynebacterium diphtheriae).
Diphtheria is a serious contagious infection of the upper respiratory tract caused by the bacterium Corynebacterium diphtheriae, which produces an exotoxin responsible for forming a characteristic pseudomembrane in the throat.

Step-by-Step Solution

1
Identify the causative organism for each disease option listed.
Diphtheria is caused by Corynebacterium diphtheriae (bacterium); Rabies is caused by Rabies virus (virus); Sleeping sickness is caused by Trypanosoma brucei (protozoan); Athlete's foot is caused by Trichophyton species (fungus).
Classifying pathogens by biological kingdom/type determines the mechanism of infection and appropriate medical intervention.
2
Select the disease that corresponds strictly to a bacterial etiology.
Diphtheria is the only disease in the list caused by a bacterium.
Antibiotics are effective against bacterial pathogens like Corynebacterium diphtheriae, whereas viral, protozoan, and fungal infections require distinct therapeutic agents.

Key Concept

Pathogen Etiology of Infectious Human Diseases
Estimated Time:1m 0s
Question 2575Question →

Based on the family relationships described below, match each person in List I with their correct relationship to AA in List II:

- AA and DD are a married couple, where AA is male.
- BB and CC are the children of AA and DD, where BB is male and CC is female.
- EE is the son of CC.
- FF is the daughter of BB.

Click a left item, then click its matching right item

Items

B
D
E
F

Matches

Show answer & explanation

Answer

B corresponds to Son of A; D corresponds to Wife of A; E corresponds to Grandson of A; and F corresponds to Granddaughter of A.
Each member is mapped according to explicit generation depth and gender: D is the female spouse (Wife of A), B is the male child (Son of A), E is the child of daughter C (Grandson of A), and F is the female child of son B (Granddaughter of A).

Step-by-Step Solution

1
Determine the relationship between A and D
Since A and D are married and A is male, D is female and is the Wife of A.
Marriage establishes a spouse relationship between A and D.
2
Determine the relationship of B to A
B is a male child of A and D, so B is the Son of A.
Direct male offspring of a parent is a son.
3
Determine the relationship of E to A
C is the female child (daughter) of A, and E is the male child (son) of C. Thus, E is the Grandson of A.
A child's child represents the grand-generation, specifically maternal grandson here.
4
Determine the relationship of F to A
B is the son of A, and F is the female child (daughter) of B. Thus, F is the Granddaughter of A.
A son's daughter is a paternal granddaughter.

Key Concept

Multi-generational Family Tree Relationship Deduction
Question 2576Question →

Satellite orbits around Earth are designated according to their altitude above the Earth's surface. Arrange the following satellite orbits in increasing order of their average altitude from the surface of Earth (from lowest altitude to highest altitude).

Drag items to arrange them in the correct order

Show answer & explanation

Answer

The correct sequence from lowest to highest altitude is Low Earth Orbit (LEO), followed by Medium Earth Orbit (MEO), and finally Geostationary Earth Orbit (GEO).
Low Earth Orbit (LEO) is closest to Earth at 160–2,000 km160\text{--}2,000\text{ km}, followed by Medium Earth Orbit (MEO) extending from 2,000 km2,000\text{ km} up to 35,786 km35,786\text{ km}, and Geostationary Earth Orbit (GEO) positioned at a high altitude of 35,786 km35,786\text{ km}.

Step-by-Step Solution

1
Identify the altitude range for Low Earth Orbit (LEO).
LEO ranges from approximately 160 km160\text{ km} to 2,000 km2,000\text{ km} altitude.
It is the closest orbit to Earth.
2
Identify the altitude range for Medium Earth Orbit (MEO).
MEO ranges from approximately 2,000 km2,000\text{ km} up to 35,786 km35,786\text{ km} altitude.
It lies between Low Earth Orbit and Geostationary Earth Orbit.
3
Identify the altitude for Geostationary Earth Orbit (GEO).
GEO is positioned at a fixed altitude of approximately 35,786 km35,786\text{ km}.
This specific altitude matches Earth's rotational period of approximately 24 hours.
4
Arrange the orbits in increasing order of altitude.
Sequence: LEO (160–2,000 km160\text{--}2,000\text{ km}) →\rightarrow MEO (2,000–35,786 km2,000\text{--}35,786\text{ km}) →\rightarrow GEO (35,786 km35,786\text{ km}).
Ordering from lowest numeric altitude to highest altitude.

Key Concept

Classification of satellite orbits by altitude (LEO, MEO, GEO)
Question 2577Question →

Consider the following statements regarding skill development initiatives and key labor market indicators in India:

1. SANKALP (Skill Acquisition and Knowledge Awareness for Livelihood Promotion) is a World Bank-assisted project under the Ministry of Skill Development and Entrepreneurship focusing on district-level skilling ecosystems and institutional strengthening.
2. The Labor Force Participation Rate (LFPR) is defined as the percentage of persons in the labor force (either employed or actively seeking/available for work) relative to the total population.
3. Structural unemployment refers to temporary joblessness experienced by individuals who are in the process of moving between jobs or entering the labor market for the first time.

Which of the statements given above are correct?

Show answer & explanation

Answer: 1 and 2 only

Answer

1 and 2 only
The combination stating that only statements 1 and 2 are correct is accurate. SANKALP is a Centrally Sponsored Scheme assisted by the World Bank to enhance district-level skilling institutions. LFPR correctly measures the total economically active population (employed plus unemployed seeking work) as a percentage of the total population. Statement 3 describes frictional unemployment, not structural unemployment.

Step-by-Step Solution

1
Evaluate Statement 1 regarding skill development initiatives.
Statement 1 is correct. SANKALP was launched by the Ministry of Skill Development and Entrepreneurship (MSDE) with World Bank loan assistance to strengthen institutional mechanisms and decentralized district-level skill training.
SANKALP focuses on convergence, quality assurance, and inclusion of marginalized groups at district levels.
2
Evaluate Statement 2 regarding labor market indicators.
Statement 2 is correct. In official statistics (such as the Periodic Labour Force Survey by NSO), LFPR = [(Employed + Unemployed) / Total Population] × 100.
LFPR includes both persons who are working and those who are unemployed but seeking work.
3
Evaluate Statement 3 regarding unemployment classifications.
Statement 3 is incorrect. Short-term unemployment occurring when individuals are between jobs or searching for initial employment is 'frictional unemployment'. 'Structural unemployment' results from long-term mismatches between economic demand and available labor skills.
Confusing frictional and structural unemployment is a common conceptual error.

Key Concept

Institutional Skill Initiatives and Unemployment Typologies
Question 2578Question →

Which of the following soil types, formed by the weathering of Deccan basaltic lava, is highly moisture-retentive and most suitable for dryland agriculture of cotton crops in plateau regions?

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Answer: Regur (Black) Soil

Answer

Regur (Black) Soil is formed from basaltic lava weathering and is renowned for its high moisture retention capacity, making it exceptionally suited for rainfed cotton farming.
Regur (Black) Soil is derived from basaltic lava flows found extensively across plateau regions. Its high clay content gives it strong moisture-retention properties, making it optimal for cotton and oilseed agriculture.

Step-by-Step Solution

1
Identify parent rock material and soil characteristics mentioned in the question stem.
The stem specifies soil formed from basaltic lava with high moisture retention suited for cotton.
Parent rock (basalt) and physical property (moisture retention) determine the primary soil category.
2
Match the soil properties to the correct agricultural classification.
Regur (Black) soil is self-ploughing, rich in clay, retains moisture for long periods, and is famously known as black cotton soil.
Black soil is the characteristic soil type of the volcanic Deccan Trap region.

Key Concept

Soil Types and Agricultural Adaptation in State Regions
Question 2579Question →

The historic Paika Rebellion of 1817, an early armed uprising against British East India Company rule, originated in which of the following modern Indian states?

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Answer: Odisha

Answer

Odisha
The correct answer is Odisha. The Paikas were the traditional landed militia of the Gajapati rulers of Odisha. In 1817, led by Bakshi Jagabandhu Bidyadhar, they revolted against the extortionate land revenue policies and administrative oppression of the British East India Company in Khurda, Odisha.

Step-by-Step Solution

1
Identify the historical movement and its regional origin
The Paika Rebellion was an armed uprising of traditional landed militia (Paikas) against British rule in 1817.
Understanding the geographical region of key state-level historical resistance movements is fundamental to state history.
2
Map the historical region to modern state boundaries
The movement occurred in Khurda, which is located in the modern state of Odisha.
Connecting historical administrative regions to contemporary states confirms the correct answer.

Key Concept

Regional Peasant and Tribal Historical Movements
Question 2580Question →

With reference to the Santhal Rebellion (1855–1856), a major tribal uprising in regional state history, consider the following statements:

1. The rebellion was led primarily by the brothers Sidhu and Kanhu Murmu.
2. The movement was geographically centered in the Damin-i-Koh region around the Rajmahal Hills.
3. The rebellion was launched in direct response to the legislative reforms introduced under the Government of India Act 1858.

Which of the statements given above are correct?

Show answer & explanation

Answer: 1 and 2 only

Answer

1 and 2 only
The Santhal Rebellion (1855–1856) was a prominent regional tribal uprising led by Sidhu and Kanhu Murmu in the Damin-i-Koh region around the Rajmahal Hills against oppressive revenue extraction. Statements 1 and 2 are accurate, while statement 3 is historically inaccurate as the uprising occurred before the Government of India Act 1858.

Step-by-Step Solution

1
Evaluate Statement 1 regarding movement leadership
Sidhu and Kanhu Murmu were the principal leaders who mobilized the Santhals.
Historical records verify that the Murmu brothers declared insurrection against local exploiters in June 1855.
2
Evaluate Statement 2 regarding geographical region
The movement was concentrated in the Damin-i-Koh region of the Rajmahal Hills.
Damin-i-Koh was a demarcated tract assigned to Santhals, where revenue exploitation sparked the rebellion.
3
Evaluate Statement 3 regarding chronological context and colonial acts
Statement 3 is historically incorrect.
The rebellion was suppressed by early 1856, whereas the Government of India Act 1858 was enacted after the Revolt of 1857.

Key Concept

Santhal Rebellion and Regional Tribal Movements
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