Life Sciences (XL) PYQs Feb 2013

General Aptitude and Chemistry

The rate of a chemical reaction is tripled when the temperature of the reaction is increased from 298 K to 308 K. The ac

Mechanistically, molecular bonding involves hybridization and orbital overlap dictate geometry and reactivity. This validates Option NAT because it satisfies bonding and stability criteria, a pattern repeatedly demonstrated in chemistry research.

Ref: Atkins and de Paula, Physical Chemistry, 11th Edition, Chapter 14, Molecular Structure and Bonding, discusses VSEPR, hybridization, molecular orbitals, dipole moments and spectroscopic properties explaining chemical bonding and reactivity.

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General Aptitude and Chemistry

Iodine forms an anionic species Q in aqueous solution of iodide(I ⁻ ). The number of lone pair(s) of electrons on the ce

evolutionary adaptation analysis shows selection and population dynamics shape traits. Consequently Option NAT emerges as the valid choice since it explains adaptive diversity, aligning with established principles in ecology and evolution literature.

Ref: Futuyma and Kirkpatrick, Evolution, 4th Edition, Chapter 11, Natural Selection and Adaptation, covers selection mechanisms, speciation, molecular evolution, phylogenetics and evolutionary genetics providing evolutionary framework.

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General Aptitude and Chemistry

When dissolved in water, the number of H ⁺ ions released from a molecule of H ₃ BO ₃ is _________

This outcome reflects molecular bonding, where hybridization and orbital overlap dictate geometry and reactivity. Option NAT captures this correctly because it satisfies bonding and stability criteria, consistent with textbook descriptions and experimental observations in chemistry.

Ref: Atkins and de Paula, Physical Chemistry, 11th Edition, Chapter 14, Molecular Structure and Bonding, discusses VSEPR, hybridization, molecular orbitals, dipole moments and spectroscopic properties explaining chemical bonding and reactivity.

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General Aptitude and Chemistry

The number of 2-center-2-electron bonds in anhydrous AlCl ₃ is ___________

This outcome reflects molecular bonding, where hybridization and orbital overlap dictate geometry and reactivity. Option NAT captures this correctly because it satisfies bonding and stability criteria, consistent with textbook descriptions and experimental observations in chemistry.

Ref: Clayden, Greeves and Warren, Organic Chemistry, 2nd Edition, Chapter 5, Pericyclic Reactions, covers Diels-Alder cycloaddition, orbital symmetry, stereochemistry and reaction mechanisms providing foundation for organic transformations.

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Physiology Ecology and Evolution

Which of the following statements is NOT CORRECT in relation to muscle proteins ?

enzyme kinetics analysis shows substrate binding and catalytic efficiency determine reaction rates. Consequently Actomyosin is not the main state of actin and myosin in post-mortem muscles emerges as the valid choice since it reflects active-site specificity and regulation, aligning with established principles in biochemistry literature.

Ref: Berg, Tymoczko, Gatto and Stryer, Biochemistry, 9th Edition, Chapter 13, Metabolism and Bioenergetics, covers glycolysis, citric acid cycle, oxidative phosphorylation and energy transduction, detailing biochemical principles of cellular energy metabolism.

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Physiology Ecology and Evolution

Which of the following carbohydrates is NOT classified as dietary fibre?

Mechanistically, enzyme kinetics involves substrate binding and catalytic efficiency determine reaction rates. This validates Tapioca starch because it reflects active-site specificity and regulation, a pattern repeatedly demonstrated in biochemistry research.

Ref: Berg, Tymoczko, Gatto and Stryer, Biochemistry, 9th Edition, Chapter 13, Metabolism and Bioenergetics, covers glycolysis, citric acid cycle, oxidative phosphorylation and energy transduction, detailing biochemical principles of cellular energy metabolism.

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Physiology Ecology and Evolution

Kawashiorkor disease is caused due to the deficiency of

Mechanistically, core biological organization involves structure-function relationships govern cellular processes. This validates protein because it integrates fundamental life science principles, a pattern repeatedly demonstrated in general biology research. This mechanism is extensively documented and reinforced by experimental data across multiple model systems and textbook discussions.

Ref: Campbell et al., Biology, 11th Edition, Chapter 2, Chemical Basis of Life, discusses fundamental biological principles, molecular organization, cellular structure and metabolic processes providing broad foundation for life sciences understanding.

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Physiology Ecology and Evolution

In Drosophila, mutations in homeotic genes result in which one of the following developmental defects?

Understanding Mendelian segregation reveals allele distribution and recombination generate phenotypic variation. Therefore Segment-specific identities will be lost is correct because it follows segregation and linkage principles, which underpins key processes in genetics.

Ref: Pierce, Genetics: A Conceptual Approach, 6th Edition, Chapter 3, Mendelian Inheritance, discusses segregation, independent assortment, genotype-phenotype correlation and pedigree analysis providing core framework for understanding genetic transmission patterns.

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Microbiology Immunology and Biotechnology

A newly discovered, recessively-inherited disease-susceptibility trait (DS) is observed only in cotton plants with white

Biologically, Mendelian segregation operates via allele distribution and recombination generate phenotypic variation. Thus 0 % is appropriate since it follows segregation and linkage principles, reinforcing core concepts taught in genetics.

Ref: Griffiths et al., Introduction to Genetic Analysis, 11th Edition, Chapter 5, Linkage and Recombination, explains chromosomal mapping, crossing over, genetic distance and recombination frequencies underlying inheritance and variation.

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Microbiology Immunology and Biotechnology

Among the following options, choose the one that is probably a cause of rapid diversification of animal groups during th

Evidence for core biological organization indicates structure-function relationships govern cellular processes. Option D aligns with this, as it integrates fundamental life science principles, reflecting standard interpretations in general biology. This mechanism is extensively documented and reinforced by experimental data across multiple model systems and textbook discussions.

Ref: Campbell et al., Biology, 11th Edition, Chapter 2, Chemical Basis of Life, discusses fundamental biological principles, molecular organization, cellular structure and metabolic processes providing broad foundation for life sciences understanding.

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Microbiology Immunology and Biotechnology

The term “ecological succession” refers to:

In general aptitude, verbal and logical reasoning dictates that grammar, vocabulary and inference determine correct usage. Therefore All the above is correct as it meets linguistic and logical standards, supported by mechanistic studies and conserved across related systems.

Ref: Standard references on general aptitude and reasoning discuss critical thinking, odd one out, inference, argument evaluation and comprehension skills supporting aptitude preparation and analytical assessment methods for examinations.

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Microbiology Immunology and Biotechnology

A bacterial population increases from 10 ³ cells to 10 ⁹ cells in 10 h. Calculate the number of generations per hour.

The principle of membrane organization explains that lipid bilayer and protein trafficking maintain compartmentalization. Hence 2 fits best because it aligns with organelle function and transport, as documented in authoritative sources on cell biology.

Ref: Cooper and Hausman, The Cell: A Molecular Approach, 8th Edition, Chapter 14, Cell Cycle and Division, explains cyclins, cyclin-dependent kinases, checkpoints and mitotic regulation detailing mechanisms governing proliferation and genomic stability.

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