Life Sciences (XL) PYQs Feb 2018

Physiology Ecology and Evolution

The rate of heat transfer per unit area from a metal plate is 1000 W m ⁻² . The surface temperature of the plate is 120

Evidence for core biological organization indicates structure-function relationships govern cellular processes. Option NAT 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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Physiology Ecology and Evolution

A microbial sample taken at 10 AM contained 1x10 ⁵ CFU/mL. The count reached to 1x10 ¹⁰ CFU/mL at 8 PM of the same day.

Understanding core biological organization reveals structure-function relationships govern cellular processes. Therefore Option NAT is correct because it integrates fundamental life science principles, which underpins key processes in general biology. This mechanism is extensively documented and reinforced by experimental data across multiple model systems and textbook discussions.

Ref: Alberts et al., Essential Cell Biology, 5th Edition, Chapter 1, Introduction to Cells, covers cellular organization, molecular mechanisms, genetic information and biological systems offering integrated perspective on core life science concepts.

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Physiology Ecology and Evolution

For an enzyme catalyzed reaction S→ P , the kinetic parameters are: [S] = 40 μM, V0 = 9.6 μM s ⁻¹ and Vmax = 12.0 μM s ⁻

Evidence for enzyme kinetics indicates substrate binding and catalytic efficiency determine reaction rates. Option NAT aligns with this, as it reflects active-site specificity and regulation, reflecting standard interpretations in biochemistry.

Ref: Nelson and Cox, Lehninger Principles of Biochemistry, 7th Edition, Chapter 6, Enzyme Kinetics and Regulation, discusses Michaelis-Menten equation, catalytic mechanisms, allosteric control and metabolic integration supporting enzyme function and pathway regulation.

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Physiology Ecology and Evolution

Ambient air at 30 ◦ C dry bulb temperature and 80% relative humidity was heated to a dry bulb temperature of 80 ◦ C in a

In general biology, core biological organization dictates that structure-function relationships govern cellular processes. Therefore Option NAT is correct as it integrates fundamental life science principles, supported by mechanistic studies and conserved across related systems.

Ref: Alberts et al., Essential Cell Biology, 5th Edition, Chapter 1, Introduction to Cells, covers cellular organization, molecular mechanisms, genetic information and biological systems offering integrated perspective on core life science concepts.

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Physiology Ecology and Evolution

The oxygen transmission rate through a 2.54 x 10 ⁻³ cm thick low density polyethylene film with air on one side and iner

Evidence for Mendelian segregation indicates allele distribution and recombination generate phenotypic variation. Option NAT aligns with this, as it follows segregation and linkage principles, reflecting standard interpretations in genetics. This mechanism is extensively documented and reinforced by experimental data across multiple model systems and textbook discussions.

Ref: Hartl and Jones, Genetics: Analysis of Genes and Genomes, 8th Edition, Chapter 7, Mutation and DNA Repair, covers mutation types, repair pathways, chromosomal aberrations and genome stability relevant to human genetic disorders.

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Physiology Ecology and Evolution

The initial moisture content of a food on wet basis is 50.76%. Its moisture content (%) on dry basis is _______.(up to t

This outcome reflects core biological organization, where structure-function relationships govern cellular processes. Option NAT captures this correctly because it integrates fundamental life science principles, consistent with textbook descriptions and experimental observations in general biology.

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

Adult male Wistar rats were fed with a protein based diet. Total 150 g of protein was ingested per animal. If the averag

Evidence for enzyme kinetics indicates substrate binding and catalytic efficiency determine reaction rates. Option NAT aligns with this, as it reflects active-site specificity and regulation, reflecting standard interpretations in biochemistry.

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

In a population which is in Hardy-Weinberg equilibrium, the frequency of occurrence of a disorder caused by recessive al

This outcome reflects Mendelian segregation, where allele distribution and recombination generate phenotypic variation. Option NAT captures this correctly because it follows segregation and linkage principles, consistent with textbook descriptions and experimental observations in genetics.

Ref: Hartl and Jones, Genetics: Analysis of Genes and Genomes, 8th Edition, Chapter 7, Mutation and DNA Repair, covers mutation types, repair pathways, chromosomal aberrations and genome stability relevant to human genetic disorders.

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Physiology Ecology and Evolution

A population of rabbits was determined to have a birth rate of 200 and mortality rate of 50 per year. If the initial pop

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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Microbiology Immunology and Biotechnology

The following stoichiometric equation represents the conversion of glucose to lactic acid in a cell: If the free energy

Evidence for enzyme kinetics indicates substrate binding and catalytic efficiency determine reaction rates. Option NAT aligns with this, as it reflects active-site specificity and regulation, reflecting standard interpretations in biochemistry.

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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Microbiology Immunology and Biotechnology

The initial concentration of cells (N0) growing unrestricted in a culture is 1.0×10 ⁶ cells/mL. If the specific growth r

Understanding membrane organization reveals lipid bilayer and protein trafficking maintain compartmentalization. Therefore Option NAT is correct because it aligns with organelle function and transport, which underpins key processes in cell biology.

Ref: Lodish et al., Molecular Cell Biology, 8th Edition, Chapter 13, Cytoskeleton and Motility, covers microtubules, actin filaments, intermediate filaments and motor proteins explaining cellular architecture, intracellular transport and motility.

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Microbiology Immunology and Biotechnology

A continuous cell culture being carried out in a stirred tank reactor is described in terms of its cell mass concentrati

Biologically, enzyme kinetics operates via substrate binding and catalytic efficiency determine reaction rates. Thus Option NAT is appropriate since it reflects active-site specificity and regulation, reinforcing core concepts taught in biochemistry.

Ref: Lehninger Principles of Biochemistry, 7th Edition, Chapter 15, Metabolic Regulation, explains hormonal control, allosteric regulation, feedback inhibition and pathway coordination essential for understanding intermediary metabolism and homeostasis.

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