CSIR-NET Life Sciences December 2024 Question Paper (Shift 2) with Answer Key and Solutions

(2025)²⁰²⁵ − (2025)²⁰²⁴ is NOT divisible by

1. 18
2. 213
3. 323
4. 433

Choose the arrangement in the increasing order of size for an average human being:

A: arm, B: toe, C: head, D: heart.

1. 1A, B, C, D
2. 2B, D, C, A
3. 3A, B, D, C
4. 4B, C, D, A

Three positive integers a, b, c, have a sum of 15. Then the minimum value of (a−2)² + (b−2)² + (c−2)² would be

1. 125
2. 227
3. 329
4. 431

The diagram shows the rate of diamonds of different sizes. Of what size is the largest diamond that can be purchased for Rs. 4.5 lakh?

1. 11.5 carat
2. 22.25 carat
3. 32.5 carat
4. 44.5 carat

How quickly must Rajesh drive the remaining distance to reach the city at an average speed of 100 km/h if he travels halfway there at 50 km/h?

1. 1150 km/h
2. 2100 km/h
3. 3125 km/h
4. 4Average speed of 100 km/h is not possible in this case.

Square of 5% is closest to

1. 10.25%
2. 225%
3. 32.5%
4. 41.25%

Any 9 papers printed on both sides are drawn from a book. The sum of their page numbers CAN NEVER be ______.

1. 1199
2. 2219
3. 3235
4. 4256

The masses and weights of some objects on the Moon were plotted against the same quantities on the Earth. The two graphs would appear as

1. 1Graph pair 1
2. 2Graph pair 2
3. 3Graph pair 3
4. 4Graph pair 4

A rectangular sheet 31.4 cm × 10 cm is rolled across its length to make a cylinder and both ends of the cylinder are covered with additional circular sheets. What will be the total surface area of the covered cylinder approximately?

1. 1314 cm²
2. 2392.5 cm²
3. 3471 cm²
4. 4785 cm²

A person covers 1/10, 1/6, and 1/5 of the total distance at speeds of 3 km/h, 5 km/h and 6 km/h, respectively. The remaining 16 km she covers at a speed of 16 km/h. How long does she take to travel the total distance?

1. 11 hour
2. 23 hours
3. 34 hours
4. 45 hours

To frame a portrait photo of 50 cm × 30 cm size, a 3 cm wide wooden strip is to be fixed all around the photo such that the inner periphery of the wooden strip touches the boundary of the photo. What is the total length of the wooden strip required?

1. 1150 cm
2. 2172 cm
3. 3180 cm
4. 4184 cm

In a square land of 200 m × 200 m size, saplings are to be planted such that the distance between the saplings as well as the distance of saplings from the boundary of the land are not less than 20 m. What is the maximum number of saplings that can be planted in the land?

1. 164
2. 281
3. 390
4. 4100

The bubble plot shows the relationship of Crop yield with precipitation and temperature. The size of the bubble is proportional to temperature. Which one of the following inferences CANNOT be drawn from the given plot?

1. 1Crop yield is inversely related to temperature
2. 2Precipitation and temperature are inversely related
3. 3Crop yield and precipitation are positively related
4. 4Precipitation and temperature are positively related

In the fictional country of Vegereversia, which of the following provinces is the odd one out?

1. 1PANGOTATOP
2. 2SULTORRAC
3. 3HIABIGOHON
4. 4SINNEGABBAC

A person orders a 12-inch circular pizza online. The restaurant calls her back and says that they ran out of 12-inch pizzas and instead offers the following choices in circular pizzas. Which of them gives the best value for her money?

1. 1Six 4-inch pizzas
2. 2Four 6-inch pizzas
3. 3Seven 3-inch pizzas
4. 4Five 5-inch pizzas

Starting with a single triangle, every iteration adds smaller triangles at each of the vertices inside the previous triangle as shown in the figure. The number of vertices in the next iteration is:

1. 115
2. 242
3. 360
4. 418

The average of 10 distinct nonnegative integers is 14.5. The average of the maximum and the minimum of these numbers is less than 15. Which of the following is the maximum possible value of the minimum?

1. 18
2. 29
3. 310
4. 411

On a spherical balloon of radius 10 cm, two dots are put at a distance of 25 units. If the balloon is uniformly expanded to a sphere of radius 50 cm, the distance between the two dots in the same units would be

1. 1100
2. 2125
3. 3150
4. 4175

How many 4-digit numbers can be generated from the digits 1, 2, 3, 4, 5, 6 and 7 such that no digit appears more than once, and ‘123’ always appear as a string?

1. 18
2. 24
3. 36
4. 412

Waters having three different colours (Red-R, Green-G, Blue-B) and temperatures: 4°C (R), 8°C (G) & 2°C (B), are put in a jar. How would these colours appear in the jar initially? (Each option lists the layers from top to bottom.)

1. 1R, G, B
2. 2G, B, R
3. 3B, G, R
4. 4G, R, B

Which one of the following properties is NOT responsible for the self-sealing nature of ruptured biological membranes?

1. 1The amphipathic character of the lipids
2. 2A hydrophobic interaction between lipid molecules
3. 3Hydrogen bonding between the head groups of the lipids and water
4. 4Covalent interactions among lipid molecules

Haploinsufficiency in tumor suppressor genes can be caused by all of the following mechanisms EXCEPT

1. 1deletion of one allele of a gene.
2. 2a missense mutation leading to increased expression of one allele.
3. 3nonsense mutation in one allele leading to truncated protein.
4. 4epigenetic silencing of one allele.

Which one of the following statements defines a monophyletic group?

1. 1A group of organisms that share a common ancestor and all of its descendants.
2. 2A group of organisms that includes species from unrelated lineages.
3. 3A group of organisms that lack a common ancestor.
4. 4A group of organisms that always lack apomorphic characters.

Which one of the following bonds support the three intertwined polypeptide strands in the triple helical structure of collagen?

1. 1Disulfide bonds
2. 2Hydrogen bonds
3. 3Co-ordinate bonds
4. 4Ionic bonds

Which one of the following phenomena describes the evolution of wings in bats, birds, and insects?

1. 1Homoplasy
2. 2Common ancestry
3. 3Pleiomorphy
4. 4Symplesiomorphy

What is the correct order of enzyme actions during the long-patch base excision repair in humans?

1. 1Glycosylase, Lyase, AP endonuclease 1, DNA Polβ, DNA Ligase 3
2. 2Glycosylase, AP endonuclease 1, DNA Polδε, Flap endonuclease 1, DNA Ligase 1
3. 3Glycosylase, AP endonuclease 1, DNA Polβ, Flap endonuclease 1, DNA Ligase 1
4. 4Glycosylase, AP endonuclease 1, DNA Polδε, Flap endonuclease 1, DNA Ligase 3

Which of the following is true for a monocot root?

1. 1Vascular bundles often polyarch; Pith large and well-developed
2. 2Vascular bundles always hexarch; Pith large and well-developed
3. 3Vascular bundles always diarch; Pith small or absent
4. 4Vascular bundles often polyarch; Pith absent

A researcher captured 60 bivalves from a habitat on day 1 and tagged all of them. On day 2, she caught 40 bivalves out of which 20 were already tagged. She then estimated the population size of bivalves in the lake using this information. Which one of the options represents the percentage of the bivalve population that were marked on day 1?

1. 110
2. 250
3. 360
4. 420

Which one of the following correctly describes how a mutagen induces a specific type of base change in DNA?

1. 1UV radiation typically creates thymine dimers causing G-C to A-T transition.
2. 2Nitrous acid deaminates adenine, leading to an A-T to G-C transition.
3. 3Ethidium bromide intercalates into DNA, causing specific base substitutions like A-T to C-G transversions.
4. 4EMS is a base analogue, causing G-C to A-T transitions.

Select the correct set of 8-mer primer pair to PCR amplify a DNA fragment containing the region shown in upper case letters below:

5′ – gagatcaggacttaGATTACAGATTACAGATTACAGATTACAggccaagtc – 3′

1. 15′ – AGGACTTA – 3′ and 5′ – GGCCAAGT – 3′
2. 25′ – TAAGTCCT – 3′ and 5′ – ACTTGGCC – 3′
3. 35′ – AGGACTTA – 3′ and 5′ – ACTTGGCC – 3′
4. 45′ – AGGACTTA – 3′ and 5′ – AGATTACA – 3′

Which one of the following options suggests indirect selection in a population?

1. 1Survival rate
2. 2Reproductive rate
3. 3Selection via kin associations
4. 4Selection via deleterious mutations

Which one of the following statements regarding the cadherin superfamily proteins is correct?

1. 1Non-classical cadherins Fat and Flamingo, regulate epithelial growth and cell polarity, respectively.
2. 2In an early mouse embryo, anti-N cadherin antibody prevents compaction.
3. 3P-cadherins lack transmembrane domain and are anchored to the membrane by GPI anchors.
4. 4Loss of the non-classical cadherin desmoglein causes skin blistering due to increased keratinocyte cell-to-cell adhesion.

Which one of the following is NOT called secondary bile acid?

1. 1Deoxycholic acid
2. 2Lithocholic acid
3. 3Chenodeoxycholic acid
4. 4Ursodeoxycholic acid

Match the following:

Which one of the following options represents all correct matches between Column X and Column Y?

1. 1A (iii), B (iv), C (i), D (ii)
2. 2A (iv), B (iii), C (i), D (ii)
3. 3A (iv), B (iii), C (ii), D (i)
4. 4A (iii), B (iv), C (ii), D (i)

Which one of the following statements best describes the functions of the SNARE protein complex in vesicular transport?

1. 1It catalyzes the hydrolysis of GTP to GDP during vesicle movement.
2. 2It provides structural support to the microtubule network.
3. 3It facilitates the fusion of vesicles with target membranes.
4. 4It transports cargo along actin filaments via motor proteins.

The presence and abundance of a species in a local community is dependent on multiple processes. Which one of these processes is UNLIKELY to depend on intra- or inter-specific interactions?

1. 1Dispersal
2. 2Niche differentiation
3. 3Demographic stochasticity
4. 4Resource competition

Skeletal muscle cells need to convert pyruvate to lactate while sustaining anaerobic respiration to

1. 1facilitate TCA cycle.
2. 2maintain the acidic extracellular environment.
3. 3recycle NADH.
4. 4generate more ATPs from the NADH.

Which one of the following features distinguishes Echinoderms from Cnidarians?

1. 1The absence of sexual reproduction.
2. 2The presence of radial symmetry.
3. 3The total number of germ layers present.
4. 4The presence of a network of water-filled tubes for movement.

Which one of the following statements is INCORRECT about lectotype designation, following ICBN rules?

1. 1A syntype is preferred over an isotype.
2. 2An isotype must be chosen over a syntype.
3. 3If syntype or isosyntype and isotype are not available, a paratype can be chosen.
4. 4In the absence of any type material, a lectotype can be chosen among the uncited specimens of any original material.

Column X lists Pattern Recognition Receptors (PRRs) and Column Y lists the ligands that bind to the PRRs.

Which one of the following options represents all correct matches between Column X and Column Y?

1. 1A-iii, B-v, C-i
2. 2A-iii, D-ii, F-v
3. 3C-i, D-ii, F-iv
4. 4B-iv, E-vi, F-i

Which experiment would be most effective in assessing the synergistic role of mycorrhizal fungi and plants in phytoremediation?

1. 1Comparing pollutant uptake in plants with and without fungal inoculation under identical soil conditions.
2. 2Analysing fungal growth rates in polluted versus unpolluted soil.
3. 3Measuring the root-to-shoot ratio of plants grown in polluted soil with fungal inoculation.
4. 4Assessing photosynthetic rates in inoculated versus uninoculated plants.

Which of the following enzymes is used for conversion of blood glucose to gluconolactone in commercially available blood glucometer?

1. 1Glucose oxidase
2. 2Glucose reductase
3. 3Glucose dehydrogenase
4. 4Gluconolactonase

In life history theory, the concept of ‘cost of reproduction’ refers to:

1. 1reduced future reproductive output or survival due to current reproduction.
2. 2reduced current reproductive output to conserve energy for future reproduction.
3. 3trade-offs between foraging rates and reproduction.
4. 4trade-offs between mating and territorial defense.

Sheep RBCs (SRBCs) were added in wells 1-10 of a micro-titre plate as shown in the figure below. Next, serum from a mouse that had been immunized with SRBCs was diluted 1/50 in a tube and then added in serial two-fold dilutions from wells 1-9.

Which of the following statements is correct about titre of anti-SRBC antibodies in the serum sample?

1. 1The titre is 1/400.
2. 2The titre is 1/6.
3. 3The titre is 1/800.
4. 4The titre is 1/8.

Which one of the following statements is INCORRECT regarding pattern formation during embryogenesis in Arabidopsis?

1. 1The zygote is unpolarized with respect to its intracellular composition.
2. 2The two daughter cells that arise from the first mitotic division of zygote has distinct developmental fates.
3. 3The cells derived from the basal quartet of the apical cell give rise to the apical regions of the root meristem.
4. 4The hypophysis derived from the uppermost cell of the suspensor gives rise to the quiescent center of the root apical meristem.

During the most common form of protein glycosylation in the ER, a preformed precursor oligosaccharide which is transferred as a complete unit to the asparagine residue in a protein is:

1. 13 N-acetylglucosamines, 10 mannoses and 4 glucoses
2. 22 N-acetylglucosamines, 9 mannoses and 3 glucoses
3. 33 N-acetylglucosamines, 9 mannoses and 3 glucoses
4. 42 N-acetylglucosamines, 8 mannoses and 3 glucoses

Which one of the following statements is true about cellular senescence?

1. 1Insulin signaling activates FoxO, and FoxO promotes senescence.
2. 2Insulin signaling inhibits FoxO, and FoxO protects cells from senescence.
3. 3Insulin signaling activates FoxO, and FoxO protects cells from senescence.
4. 4Insulin signaling inhibits FoxO, and FoxO promotes senescence.

A grassland has five sympatric species of grasshoppers. Males sing species-specific songs to attract conspecific females. The song represents which mode(s) of reproductive isolation?

1. 1postmating and prezygotic
2. 2postzygotic
3. 3premating and postzygotic
4. 4premating

Which one of the following statements about DNA packaging in chromosomes is INCORRECT?

1. 1Condensin I creates loops of nucleosomal chromatin for packaging in mitosis.
2. 2Histone H1 is required for higher order packaging of mammalian chromosomes.
3. 3Histones form hydrogen bonds with the sugar-phosphate backbone of DNA.
4. 4Histone modification is not required for mitotic chromosome condensation; it is mainly required for epigenetic control of gene repression in interphase.

Which one of the following is NOT a true effect of aldosterone on the principal cells of distal tubule and the collecting duct to increase the reabsorption of Na⁺?

1. 1Stimulation of CAP1 levels
2. 2Decrease in the serum and glucocorticoid-regulated kinase 1 (Sgk1) levels
3. 3Increase in the expression of ENaC in the apical membrane
4. 4Increase in the amount of Na⁺, K⁺-ATPase in the basolateral membrane

Which one of the following does NOT increase airways resistance in lungs?

1. 1Norepinephrine
2. 2Thromboxane A₂
3. 3Histamine
4. 4Leukotriene B₄

For expression of a gene of interest (Goi) and a green fluorescent protein (GFP) in mammalian cells, Goi and GFP must be expressed in a single mRNA, but translated independently. Which one of the following would be the structure of the expression construct?

(Pro – promoter; Enh – enhancer; IRES – internal ribosome entry site; pA – poly adenylation signal sequence)

1. 1Pro – Enh – Goi – IRES – GFP – pA
2. 2Enh – Pro – Goi – GFP – IRES – pA
3. 3Pro – Enh – Goi – GFP – IRES – pA
4. 4Enh – Pro – Goi – IRES – GFP – pA

Which one of the following is NOT required for isotype switching from IgM to IgE?

1. 1VDJ recombination
2. 2Double stranded break repair
3. 3Cell division
4. 4T cell cytokines

Acetohydroxy acid synthase (AHAS), an enzyme involved in branched-chain amino acid biosynthesis, is inhibited by all the following classes of herbicides, EXCEPT

1. 1Imidazolinones
2. 2L-phosphinothricin
3. 3Sulfonylureas
4. 4Triazolopyrimidines

A desert annual plant with long-duration seed dormancy germinates only after heavy rainfall. What life history trait does this illustrate?

1. 1Bet-hedging strategy
2. 2K strategy
3. 3Frequency-dependent reproduction
4. 4Density-dependent reproduction

Ten bacterial cells are inoculated into 10 ml of Luria broth and grown for 10 hours with shaking at 37°C. What will be the approximate number of bacteria in the flask at the end of 10-hour incubation? (Note: the doubling time of this bacterium in Luria broth is approximately 20 min).

1. 110⁶
2. 210⁸
3. 310⁹
4. 410¹⁰

Which one of the following statements is INCORRECT regarding seasonality and sex in aphids?

1. 1An egg hatched in the spring gives rise to several generations of parthenogenetically reproducing females.
2. 2During autumn, a particular type of female is produced whose eggs can give rise to only asexual males.
3. 3After winter, when eggs hatch, each one gives rise to an asexual female.
4. 4The juvenile hormone controls the parthenogenetic/sexual switch and also inhibits the formation of wings.

In a population, the frequency of allele ‘a’ is 0.2 and that of allele ‘b’ is 0.1. Consider that there are two alleles for each of the genes. What would be the expected percentage of population with genotype AaBb, considering that the population is under Hardy-Weinberg equilibrium?

1. 11.44 %
2. 22.88 %
3. 350 %
4. 457.6 %

Which one of the following plants has a bisporic type of embryo sac development?

1. 1Allium
2. 2Oenothera
3. 3Plumbago
4. 4Polygonum

Which one of the following plant pathogens has the most prolonged symptomless infection phase?

1. 1Phytophthora infestans
2. 2Magnaporthe oryzae
3. 3Botrytis cinerea
4. 4Mycosphaerella fijiensis

Which one of the following translation systems is inhibited by cycloheximide?

1. 170S ribosome-associated bacterial translation system
2. 280S ribosome-associated eukaryotic cytosolic translation system
3. 374S ribosome-associated mitochondrial translation system
4. 470S ribosome-associated chloroplast translation system

Which one of the following statements is correct?

1. 1The ALS selection marker gene used for development and selection of transgenic plants confers resistance to the antibiotic, ampicillin.
2. 2A T0 transgenic plant containing two tightly linked copies of a transgene expression cassette would show segregation of the transgenic phenotype in a 15:1 ratio in the T1 generation obtained by self-pollination.
3. 3Non-conditional, negative selection marker genes cannot be expressed under a constitutive promoter for selection of transgenic plants.
4. 4Transgenic plants containing multiple copies of the T-DNA are preferred for field studies as they would always show increased expression levels of the transgene across multiple generations.

Which one of the following statements is correct?

1. 1A population of a diploid species can possess only two allelic forms of a gene.
2. 2In codominance, the phenotype of the heterozygote lies in the range between the phenotypes of individuals that are homozygous for either allele involved.
3. 3Penetrance is the frequency with which a genotype manifests itself in individuals in a given population.
4. 4Expressivity is the type or degree of phenotypic manifestation of a penetrant allele or genotype in a particular individual and is not influenced by the environment.

Which of the following phytohormone signaling pathways are evolutionarily related to bacterial two-component regulatory systems?

1. 1Cytokinin and ethylene
2. 2Brassinosteroid and auxin
3. 3Auxin and cytokinin
4. 4Brassinosteroid and strigolactone

The pKa of an amino acid side chain was measured in aqueous solution. Which one of the following is the correct arrangement of the amino acids in the decreasing order of their side chain pKa?

1. 1Serine > Lysine > Histidine > Aspartate
2. 2Lysine > Histidine > Aspartate > Serine
3. 3Aspartate > Histidine > Lysine > Serine
4. 4Serine > Histidine > Lysine > Aspartate

Which one of the following statements best illustrates a dominant negative mutation?

1. 1A mutation in a growth factor receptor gene leads to an overactive receptor that signals constantly, even in the absence of a signal.
2. 2A mutation in an enzyme-coding gene decreases its activity, but enough enzyme activity remains in heterozygotes to maintain normal metabolic function.
3. 3A mutation in a transcription factor gene reduces its ability to bind DNA, but there is no effect on gene expression unless both alleles are mutated.
4. 4A mutation in a structural protein gene produces an altered protein that can interact with its wild type counterpart and disrupt its function.

In a developing Drosophila embryo, which one of the following is the correct order of Hox gene expression from the anterior-to-posterior axis?

1. 1Antennapedia, Ultrabithorax, Abdominal A
2. 2Abdominal A, Ultrabithorax, Antennapedia
3. 3Antennapedia, Abdominal A, Ultrabithorax
4. 4Ultrabithorax, Antennapedia, Abdominal A

Which one of the following is NOT a vitamin K-dependent blood clotting factor?

1. 1Factor II
2. 2Factor V
3. 3Factor IX
4. 4Factor X

Which one of the following statements represents correct sequence of events during electron transport chain from P680 to P700 in a light reaction of photosynthesis in a typical plant?

1. 1Plastocyanin – Plastoquinone A – Plastoquinone B – Cytochrome b₆f complex – Pheophytin
2. 2Plastocyanin – Cytochrome b₆f complex – Plastoquinone A – Plastoquinone B – Pheophytin
3. 3Pheophytin – Plastoquinone A – Plastoquinone B – Cytochrome b₆f complex – Plastocyanin
4. 4Pheophytin – Cytochrome b₆f complex – Plastoquinone A – Plastoquinone B – Plastocyanin

In the context of gene expression, what is the primary function of the mediator complex in eukaryotes?

1. 1To modify histones to promote transcription
2. 2To facilitate the interaction between transcription factors and RNA polymerase II
3. 3To promote helicase activity to unwind DNA during transcription initiation
4. 4To degrade mRNA after transcription

The figure below depicts the allosteric regulation in the biosynthesis of three aromatic amino acids- Phe, Tyr and Trp, acting at four major steps catalyzed by enzymes, CM, AS, ADT and ADH. The feedback regulation and relaxation of enzyme activities by the end-product amino acids are marked.

Following assumptions are made regarding the pool of aromatic amino acids in the feedback-insensitive mutants of these allosteric enzymes.

1. A. The feedback-insensitive mutant of CM will show higher pool of Phe and Tyr.
2. B. The feedback-insensitive mutant of AS will increase only Trp pool.
3. C. The feedback-insensitive mutant of AS will show higher pool of Trp, Phe and Tyr.
4. D. In feedback-insensitive mutant of ADH, only Tyr pool is decreased.
5. E. In feedback-insensitive mutant of ADH, both Tyr and Phe pools are increased transiently.

Which one of the following options represents a combination of all correct assumptions?

1. 1A, B and D
2. 2A, C and E
3. 3B, C and E
4. 4C, D and E

The graph below shows the plot of 1/v vs 1/[S] for an enzymatic reaction, with the solid and dashed lines representing the reactions without and with an inhibitor, respectively. The concentration of the inhibitor is 1 μM.

Which one of the following will be the K_I of the inhibitor?

1. 10.33
2. 21.0
3. 30.50
4. 42.0

A region of a mouse chromosome was subjected to micrococcal nuclease hypersensitivity analysis over stages of development. In early stages, the region had regularly spaced nucleosomes. In later stages, the nucleosomes were irregularly spaced with several nucleosome free regions detected.

Based on the above observations, which one of the following is the best possible inference?

1. 1The chromatin region is a facultative heterochromatin.
2. 2The region is highly expressed in early stages.
3. 3Nucleosomes are not made efficiently in the late developmental stages.
4. 4The nucleosomal arrangements cannot be used to infer potential expression states.

Dorsal-ventral patterning in the oocyte of Drosophila depends on the expression of Gurken. The following events occur during generation of dorsal-ventral polarity.

1. A. The oocyte nucleus travels to the anterior dorsal side of the oocyte where it localizes gurken mRNA.
2. B. Gurken protein reaches only those follicle cells closest to the oocyte nucleus.
3. C. The protein product forms an anterior-posterior gradient along dorsal surface of the oocyte.

What would happen if maternal deficiency of gurken occurs?

1. 1Dorsal-ventral polarity occurs in the follicle cell layer surrounding the growing oocytes.
2. 2Dorsalized follicle cells initiate the formation of dorsal-ventral axis of the embryo.
3. 3Absence of gurken leads to repression of the pipe protein in ventral cells.
4. 4Ventralization of the embryo would occur.

ΔG⁰ of a reaction shows the following temperature dependence.

What is the expected dependence of K_eq of the reaction on the temperature, where C is a temperature-independent constant?

1. 1K_eq = C
2. 2K_eq = C × e^1/T
3. 3K_eq = C × e^−T
4. 4K_eq = − RT ln(C)

The circular dichroism spectra for near-UV and far-UV regions of a polypeptide chain are given below.

Which one of the following options represents a correct inference about the polypeptide fold based on the above data?

1. 1It contains only β sheets.
2. 2It has to be an alternate α/β fold.
3. 3It has to be a mixed α+β fold.
4. 4It belongs to either alternate α/β or mixed α+β fold.

Sturtevant introduced the concept of recombination frequency-based genetic maps. Since genetic distances between genes may be underestimated due to the occurrence of double crossovers, other mapping functions were developed to provide more accurate estimates. Haldane’s mapping function assumes no interference between crossovers, while Kosambi’s mapping function accounts for interference. The following graph presents the relationship between recombination frequency and map distance (cM) as proposed by Sturtevant and after corrections using either Haldane’s or Kosambi’s mapping functions.

The following statements were made about genetic maps.

1. A. Line I in the above plot represents relationship between recombination frequency and map distance based on Kosambi function.
2. B. The chance of underestimation of map distance increases with increase in recombination frequency.
3. C. Genetic mapping proposed by Sturtevant assumes complete interference.

Which one of the following options correctly identifies each statement as True (T) or False (F) from A to C, respectively?

1. 1T, T, T
2. 2T, T, F
3. 3T, F, T
4. 4F, T, T

A putative mitochondrial signal peptide was attached to the N-terminus of the DHFR protein and expressed in mammalian cells. Mitochondria were isolated, and a fraction was osmotically shocked briefly. Both osmotically shocked and untreated pools of mitochondria were treated with protease. It was observed that the DHFR was intact in both cases.

Which of the following statements best describes the function of the signal peptide?

1. 1It targets DHFR to the mitochondrial outer membrane, facing the cytosol.
2. 2It targets DHFR to the mitochondrial inner membrane, facing the intermembrane space.
3. 3It targets DHFR to the mitochondrial outer membrane, facing the intermembrane space.
4. 4It targets DHFR to the mitochondrial matrix.

Breast cancer stem cells may be identified by analyzing the CD24/CD44 phenotype of a breast tumor. CD24/CD44 stained cells were analyzed by flow cytometry and the analysis is shown below.

Further analyses of the sorted cells from different quadrants (Q1 to Q4) by immunoblotting revealed the following results. The dotted lines represent lanes with negligible signal.

Based on the above results, which phenotype is associated with the maximum number of breast cancer stem cells?

1. 1CD24⁻/CD44⁻
2. 2CD24⁺/CD44⁺
3. 3CD24⁻/CD44⁺
4. 4CD24⁺/CD44⁻

Two closely related individuals, suffering from a congenital disease, have several children. A genetic counselor constructs the following pedigree of the family and concluded that this disease is caused by mutations in at least two genes.

Further, based on this information, the following statements were made:

1. A. At least one of the children will not carry any mutations linked to this condition.
2. B. The mutations causing this disease are recessive.
3. C. At least one of the mutant genes is on the Y chromosome.
4. D. Simultaneous heterozygous mutations in the involved genes can cause the disease.

Which one of the following options is the combination of all correct statements?

1. 1A and B
2. 2B and C
3. 3A and D
4. 4A and C

Given below are leaf lengths (in cm) measured from a sample of 15 Dipterocarp trees

5, 6, 7, 7, 8, 8, 8, 9, 9, 10, 10, 11, 11, 12, 13

What are the mean, median, and mode of the leaf lengths?

1. 1Mean – 7.93, Median – 7, Mode – 10
2. 2Mean – 8.93, Median – 9, Mode – 8
3. 3Mean – 7.93, Median – 9, Mode – 8
4. 4Mean – 8.93, Median – 9, Mode – 9

In an experiment, while screening for loss-of-function mutants, a student found a mutation in the gene encoding caspase-9 in the intrinsic pathway of apoptosis. The following are the possible consequences for this mutant cell:

1. A. Loss of mitochondrial membrane potential and release of cytochrome C.
2. B. Reduced formation of the apoptosome and defective initiation of apoptosis.
3. C. Inability to activate the death receptors.
4. D. Become resistant to UV irradiation-induced cell death.

Which one of the following options represents all correct statements?

1. 1A, B and D
2. 2B, C and D
3. 3B and D only
4. 4A and B only

Given below are four metabolic intermediates (i-iv) listed against amino acids (A-E):

1. A. i – serine, glycine, cysteine
2. B. iv – alanine, valine, leucine
3. C. iii – glutamate, glutamine, proline
4. D. ii – methionine, threonine, lysine
5. E. i – histidine

Which one of the following options correctly pairs the metabolic intermediates with their corresponding amino acid end product(s)?

1. 1A and E
2. 2B and D
3. 3A and C
4. 4C and E

Populations of two species (A and B) follow logistic growth. The parameter values for the logistic growth equation are given in the table below.

Select the option that correctly gives the population growth rate at N = 100 for both species.

1. 1Species A = 150; Species B = 82
2. 2Species A = 200; Species B = 72
3. 3Species A = 250, Species B = 46
4. 4Species A = 300, Species B = 68

The following statements are made regarding root-knot nematode infection in plants.

1. A. Chemical signals released by the plant roots can induce hatching of the juvenile nematodes.
2. B. Mitosis coupled with cytokinesis and DNA endoreduplication is induced during root-knot nematode infection.
3. C. Nematodes form syncytial feeding structures by recruiting plant cells.
4. D. Nematode infections suppress cortical cell growth in plants.

Which one of the following options represents the combination of all correct statements?

1. 1A and B
2. 2A and C
3. 3B and C
4. 4B and D

Cholera toxin activates the chloride channel in the epithelial cells of intestine leading to loss of Cl⁻, and consequent loss of water leading to dehydration. Successful oral rehydration therapy involves supplementing water with glucose and salt and not just salt. This is

1. 1to replenish the energy lost by dehydration and replace chloride.
2. 2to create an osmotic gradient with Na⁺ and glucose to allow water to move from intestinal lumen to blood via epithelial cells.
3. 3because the epithelial antiporter pumps water inside the epithelium in the presence of salt and glucose and eventually into blood.
4. 4because sodium chloride will release Cl⁻ for replacing lost chloride along with water in the intestinal lumen.

The following statements suggest the physiological characteristics of the dead space in respiratory system, alveolar ventilation (the amount of air reaching alveoli per minute) and respiratory minute volume (RMV) in healthy individuals.

1. A. The alveolar ventilation is less than RMV.
2. B. The anatomic dead space can be estimated by the body weight of the individual.
3. C. At rest, the anatomic dead space and physiological dead space are identical.
4. D. The alveolar ventilation is higher in rapid shallow breathing than that of the slow deep breathing at the same RMV.

Which one of the following options represents the combination of correct statements?

1. 1A, B and C
2. 2B, C and D
3. 3C and D only
4. 4A only

A tetraploid plant (4X = 60 chromosomes) reproduces by obligate apomixis. However, fertilization of the central cell is required for its proper endosperm development (pseudogamy). The male meiosis in this plant is normal, giving rise to reduced gametes. What will be the chromosome numbers in the embryo and endosperm of the apomictic seeds resulting from pseudogamy?

1. 1Embryo = 30; endosperm = 90
2. 2Embryo = 60; endosperm = 150
3. 3Embryo = 60; endosperm = 90
4. 4Embryo = 60; endosperm = 120

A molecule absorbs light at ‘X’ nm wavelength and emits light as fluorescence at ‘Y’ nm wavelength. Typically, there is a shift in the wavelength (Y>X). E is the energy transferred to the solvent during reorganization of the excited state, ‘h‘ is the Planck’s constant, and ‘c’ is the speed of light.

E is equal to:

1. 1h(Y−X)
2. 2hc(Y−X) / XY
3. 3c(Y−X) / h
4. 4c / (Y−X)

If planaria is cut in transverse, active Wnt signaling in the posterior side of the head piece is essential for the regeneration of a tail. Students were investigating the role of gene abc in this process. They find that overexpressing abc in the head piece blocks tail regeneration. However, overexpressing constitutively active β-catenin along with abc in the severed head piece allows tail formation.

Which one of the following pathways correctly depicts the role of abc and β-catenin in planarian tail regeneration?

1. 1abc ⊣ Wnt → β-catenin → Tail regeneration
2. 2Wnt → β-catenin → abc ⊣ Tail regeneration
3. 3Wnt → β-catenin and abc → β-catenin; β-catenin → Tail regeneration
4. 4abc → Wnt → β-catenin → Tail regeneration

Consider the following statements on patterns in global biogeography.

1. A. The endemicity of terrestrial mammal families in biogeographic realms is greater than plant families.
2. B. There are fewer mammalian fruit eaters, omnivores, and carnivore species in Australia compared to other biogeographic realms.
3. C. Major diversification of modern mammals started only 65-55 million years ago.
4. D. On an average, plant species have dispersed much better than mammalian species across biogeographic realms.

Which one of the options given below contains the correct set of True/False statements, based on well-established patterns in global biogeography?

1. 1A: True, B: False, C: True, D: False
2. 2A: True, B: True, C: True, D: True
3. 3A: False, B: True, C: True, D: False
4. 4A: False, B: False, C: True, D: True

After synchronizing mammalian cells in culture with a double thymidine block (cell cycle duration of 24h), cells are released into fresh medium. After 6h, cells are split into 4 sets and each is treated with a) nothing, b) proteasome inhibitor, c) myosin II inhibitor, d) nocodazole.

From the options given below, choose the one that has the most likely outcome of the experiment.

1. 1a: synchronously dividing cells; b: binucleate cells; c: metaphase arrested; d: prometaphase arrested
2. 2a: synchronously dividing cells; b: prometaphase arrested; c: binucleate cells; d: metaphase arrested
3. 3a: binucleate cells; b: prometaphase arrested; c: synchronously dividing cells; d: anaphase arrested
4. 4a: synchronously dividing cells; b: metaphase arrested; c: binucleate cells; d: pro-metaphase arrested

The table below lists unique structural modifications (Column X) found in various plant genera (Column Y).

Select the option that correctly matches column X with column Y.

1. 1A-I, B-II, C-III, D-IV
2. 2A-II, B-III, C-I, D-IV
3. 3A-II, B-IV, C-I, D-III
4. 4A-III, B-IV, C-II, D-I

In order to determine the origin of replication of a circular DNA, isolated DNA from the actively replicating cells were digested with different restriction enzymes (as indicated), followed by electrophoresis in a two-dimensional gel. Southern hybridization was performed with a DNA probe as indicated.

Based on the results of the Southern blots, indicate which of the following options best describes the location of the origin of replication?

1. 1Near the EcoRI site
2. 2Near the BamHI site
3. 3Near the HindIII site
4. 4Near the KpnI site

Which one of the following scenarios is likely to produce the highest beta diversity for tree species in a forested landscape?

1. 1High gamma diversity, strong dispersal limitation, high habitat heterogeneity
2. 2High gamma diversity, weak dispersal limitation, uniform habitat
3. 3High alpha diversity, low gamma diversity, strong dispersal limitation
4. 4High alpha diversity, low gamma diversity, weak dispersal limitation

The following statements are made regarding the role of tumour microenvironment directly contributing to the metastatic process:

1. A. Hypoxia in primary tumours can induce the expression of VEGF and matrix metalloproteinases (MMPs) to promote metastasis.
2. B. Tumour-associated macrophages (TAMs) always inhibit metastasis through immune surveillance.
3. C. Cancer-associated fibroblasts (CAFs) provide structural support and secrete factors that promote metastasis.
4. D. The acidic pH of the tumour microenvironment impedes cancer cell migration.

Which one of the following options represents all correct statements?

1. 1A, C and D
2. 2B and D only
3. 3B, C and D
4. 4A and C only

A mutation in a plant gene is female gametophyte lethal. This mutant allele can be normally transmitted through pollen. However, when transmitted through egg, the embryos abort, resulting in inviable seeds irrespective of the male allele. A student harvested the seeds from a heterozygous mutant plant and grew a total of 100 plants. What is the expected number of homozygous plants in this population?

1. 125
2. 250
3. 366
4. 475

Leaves can alter the intracellular distribution of their chloroplasts in response to changing light conditions. Shown below are schematic diagram of chloroplast distribution patterns in palisade cells of Arabidopsis, in response to different light intensities, grown in a growth chamber having light source from the top.

Which one of the following combinations correctly matches the chloroplast distribution with its corresponding light intensity?

1. 1A = High light; B = Darkness; C = Low light
2. 2A = Darkness; B = High light; C = Low light
3. 3A = Low light; B = Darkness; C = High light
4. 4A = High light; B = Low light; C = Darkness

The table below lists the food reserves (Column X) found in different algal groups (Column Y).

Select the option that correctly matches column X with column Y.

1. 1A-II, B-III, C-I, D-IV
2. 2A-IV, B-III, C-II, D-I
3. 3A-III, B-II, C-I, D-IV
4. 4A-I, B-IV, C-III, D-II

In a paper wasp, a worker helps to raise 4 full-sisters instead of producing 4 offspring of her own. According to Hamilton’s rule, will selection favour this altruistic behaviour in terms of genetic units?

1. 1Yes, because 3.0 genetic units are gained and 2.0 genetic units are lost.
2. 2Yes, because 2.0 genetic units are gained and 1.0 genetic unit is lost.
3. 3No, because 2.0 genetic units are gained and 3.0 genetic units are lost.
4. 4No, because 2.0 genetic units are gained and 4.0 genetic units are lost.

Wnt/β-catenin signaling plays essential roles during development. The following statements are made about the Wnt/β-catenin signaling pathway:

1. A. In the absence of Wnt ligands, β-catenin is phosphorylated by the APC/Axin/GSK-3β complex, leading to its degradation.
2. B. The β-catenin/TCF complex acts as a repressor of gene expression upon activation of Wnt signaling.
3. C. The Wnt/β-catenin pathway is initiated by binding of Wnt ligands to receptor tyrosine kinases (RTKs).
4. D. β-catenin is involved in both cell-to-cell adhesion and transcriptional regulation.

Which one of the following options represents all correct statements?

1. 1A, B and C
2. 2A, B and D
3. 3A and D only
4. 4A and C only

In the classical metapopulation model articulated by Richard Levins (1969, 1970), the metapopulation is considered to be a collection of subpopulations occupying different patches. In this model, we consider the following conditions:

1. A. Individual subpopulations have realistic chances of both extinction and recolonization.
2. B. The dynamics of the various subpopulations should be largely independent.
3. C. Recolonization of a patch after extinction is mainly through dispersal from the mainland patch.
4. D. Population dynamics in the patches of a metapopulation should be highly synchronous.

Which one of the options given below includes conditions that should be met for a population to be considered a metapopulation?

1. 1A and B
2. 2B and C
3. 3C and D
4. 4A and D

Given below are some statements about thyroid hormone biosynthesis in thyroid gland.

1. A. An antiporter transports two Na⁺ ions and one I⁻ ion across the thyroid follicular cells.
2. B. Pendrin, a Cl⁻/I⁻ symporter helps I⁻ entry into the colloid.
3. C. Pendrin, a Cl⁻/I⁻ exchanger helps I⁻ entry into the colloid.
4. D. Iodination of tyrosine residue takes place first on the 3^rd position in the thyroglobulin protein.

Which one of the following options represents the combination of correct statements?

1. 1A and B
2. 2B and C
3. 3C and D
4. 4A and D

In a typical experiment, 15 mL of an aqueous solution containing an unknown quantity of acetylcholine had a pH of 7.65. When the solution is incubated with acetylcholinesterase, the pH of the solution decreased to 6.87. Assuming that there was no buffer in the reaction mixture, determine the number of moles of acetylcholine in the 15 mL solution.

1. 11.65 × 10⁻⁹ mol to 1.75 × 10⁻⁹ mol
2. 22.65 × 10⁻⁹ mol to 2.75 × 10⁻⁹ mol
3. 30.65 × 10⁻⁹ mol to 0.75 × 10⁻⁹ mol
4. 43.30 × 10⁻⁹ mol to 3.40 × 10⁻⁹ mol

The following table presents soil formation processes (Column X) and climatic conditions in which they occur (Column Y).

Which one of the following options represents all correct matches between Column X and Column Y?

1. 1A-I, B-III, C-II
2. 2A-III, B-II, C-IV
3. 3A-I, B-IV, C-III
4. 4A-II, B-III, C-IV

Following statements are made with respect to polar auxin transport in plants.

1. A. It proceeds via symplast.
2. B. Its velocity is faster than the phloem translocation rates.
3. C. It is specific for active auxins, both natural and synthetic.
4. D. It is mediated by protein carriers on the plasma membrane.

Which one of the following options represents the combination of all correct statements?

1. 1A and B only
2. 2C and D only
3. 3B, C and D
4. 4A, B and D

In sesame, the seed coat color is of two types: white or brown. True breeding white- and brown-seeded plants were reciprocally crossed and the results are given below.

Which one of the following types of inheritance explains the depicted transmission of seed color in sesame?

1. 1Plastid/mitochondrial gene-mediated maternal/cytoplasmic inheritance
2. 2Nuclear gene-mediated maternal effect
3. 3Polar overdominance
4. 4Incomplete maternal inheritance

The descending phase of the nerve action potential is caused by:

1. A. delayed opening of voltage-gated K⁺ ion channels.
2. B. rapid opening of voltage-gated Na⁺ ion channels.
3. C. closing of voltage-gated Na⁺ ion channels.
4. D. leaky K⁺ ion channels.

Which one of the following options represents the combination of correct statements?

1. 1A and B
2. 2A and C
3. 3B and C
4. 4B and D

Adding mRNA that encodes a eukaryotic secretory protein to a cell-free translation system initiates protein translation. Signal recognition particle in low concentration and endoplasmic reticulum (ER) treated with 1% Triton X-100 were sequentially added to the cell free translation system.

Which of the following outcomes is the most likely?

1. 1Protein synthesis will begin but terminate prematurely, leading to shorter products.
2. 2The protein will be fully synthesized and incorporated into ER.
3. 3The protein will be fully synthesized, and its signal sequence will be removed without being incorporated into the ER
4. 4The protein will be fully synthesized but not incorporated into ER.

Given below are a few statements about vesicular transport.

1. A. Clathrin-mediated endocytosis requires the recruitment of adaptors to the cytosolic face of the plasma membrane.
2. B. The low-pH environment of early endosomes leads to the dissociation of cargo from its receptor, allowing for the recycling of receptors to the plasma membrane.
3. C. The late endosomes, which mature into the lysosomes, are directly involved in the recycling of synaptic vesicle proteins in neurons.
4. D. The multivesicular body pathway involves the formation of intraluminal vesicles, which sort cargo for degradation in the lysosomes.

Which one of the following options has all correct statements about endocytosis?

1. 1A and B only
2. 2B and D only
3. 3B, C and D
4. 4A, B and D

Normal yeast cells grow at 42°C. Five yeast haploid strains, with independent alleles of YFG1 having impaired cell growth at 42°C, were isolated and labeled as yfg1ts1 to yfg1ts5. A haploid (yfg1ts1) carrying a spontaneously generated mutation (sup1) at an independent locus was isolated, which can grow at 42°C. Using pairwise crossing, sup1 was introduced into strains carrying yfg1ts2 to yfg1ts5 alleles. All these haploids grew at 42°C.

Based on this data, the following statements were made to describe the Sup1–Yfg1 molecular/genetic interaction.

1. A. Sup1 codes for a protein which, when over-expressed, stabilized mutant yfg1ts proteins.
2. B. Sup1 codes for a protein that physically interacts with Yfg1 protein.
3. C. Sup1 protein upregulates an alternate pathway.
4. D. Sup1 is a nonsense suppressor that restores protein translation in cells carrying yfg1ts allele.

Which one of the following options represents the combination of all correct statements?

1. 1A and B only
2. 2B, C and D only
3. 3A, B and C only
4. 4A, B, C and D

A student performed an ELISA to detect anti-ovalbumin IgG in a serum sample. The experiment involved the following sequential steps: coating plates with ovalbumin, blocking with BSA, adding serum sample, adding anti-mouse-IgG-HRP, adding H₂O₂ + o-Phenylenediamine dihydrochloride (OPD), and adding H₂SO₄. The student made the following statements:

1. A. If the plates are not blocked with BSA, the specificity of the assay decreases.
2. B. If the plates are not washed between addition of serum sample and addition of anti-mouse IgG-HRP, the sensitivity of the assay decreases.
3. C. If the plates are not washed between addition of anti-mouse IgG-HRP and addition of H₂O₂ + OPD, the specificity of the assay decreases.
4. D. OPD is the substrate for the enzyme.
5. E. Without H₂SO₄, no colour is developed.

Which one of the following options represents the combination of all correct statements?

1. 1A and B only
2. 2B and C only
3. 3A, B and C
4. 4A, C, D and E

The table below shows the outcomes of surgical experiments in chick embryos.

Which one of the following options represents a combination of all correct outcomes?

1. 1A and B
2. 2B and D
3. 3A and C
4. 4A and D

Based on homology, a protein, CG2024, functions as a homotetramer. The function of each unit within the tetramer is essential for its catalytic activity. CG2024 protein has three domains. Domain ‘a’ is essential for tetramerization, domain ‘b’ is essential for catalytic activity and domain ‘c’ does not contribute to CG2024 function at all. Three mutations, a*, b* and c* in the ‘a’, ‘b’ and ‘c’ domains of CG2024, respectively, have been identified. The a* and b* disrupt the function of their respective domains.

Based on this information, which one of the following options correctly describes the nature of mutations a*, b* and c* (in the same order)?

1. 1Dominant, recessive, amorphic
2. 2Dominant, dominant, amorphic
3. 3Recessive, dominant, recessive
4. 4Recessive, recessive, dominant.

The figure below represents a bipartite network of species interactions between two trophic levels. Each link represents an interaction between a species in the higher trophic level (A to H) and a species in the lower trophic level (I to P).

Given below are a few statements describing potential conclusions that can be drawn from the network:

1. A. If the network represents predator species (A-H) and prey species (I-P), then D is an apex predator.
2. B. If the network represents plant species (I-P) and pollinator species (A-H), then species I is more likely to experience local extinction than K.
3. C. The network is more stable if D is removed and the population size of O increases.
4. D. If the network represents frugivore species (A-H) and plant species (I-P), then M is a keystone species.

Which one of the options given below represents all correct statement/s that can be inferred from the network above?

1. 1A and B only
2. 2A, B and C
3. 3B, C and D
4. 4B only

Phosphoenolpyruvate carboxylase (PEPCase) is an important enzyme involved in both C4 and CAM photosynthesis. Given below are a few statements regarding PEPCase in C4 and CAM plants.

1. A. Light activates PEPCase kinase in C4 plants.
2. B. Phosphorylation inactivates PEPCase in C4 plants while it activates the enzyme in CAM plants.
3. C. PEPCase kinase gets activated by light in CAM plants.
4. D. Phosphorylated PEPCase is less sensitive to malate.

Which one of the following options is the combination of all correct statements?

1. 1A, B and C
2. 2A and D
3. 3B, C and D
4. 4C and D only

A researcher studying the mating systems in birds (operational sex ratio 1:1) uses the number of successful matings as a measure of male reproductive fitness and female reproductive fitness, as depicted in the figure below.

Which one of the following options correctly matches P and Q with the correct sex for different mating systems?

1. 1Polygyny: P, male, Q, female; Polyandry: Q, male, P, female
2. 2Polygyny: Q, male, P, female; Polyandry: P, male, Q, female
3. 3Polygyny: P, male, Q, female; Polyandry: P, male, P, female
4. 4Polygyny: Q, male, P, female; Polyandry: Q, male, Q, female

Given below are a few statements.

1. A. Codominant molecular markers ___(i)___ be used for identification of heterozygotes.
2. B. Genome wide association studies (GWAS) ___(ii)___ be performed on germplasm with high genetic diversity.
3. C. An F2 mapping population ___(iii)___ be used as an immortal population for genetic mapping studies in plants.
4. D. Bulk segregant analysis (BSA) ___(iv)___ be used for mapping of monogenic qualitative traits.

Which one of the following options represents the correct sequence of terms to fill in the blanks in the above statements so that all the statements are true?

1. 1(i) cannot, (ii) can, (iii) can, (iv) can
2. 2(i) can, (ii) cannot, (iii) cannot, (iv) cannot
3. 3(i) can, (ii) can, (iii) can, (iv) cannot
4. 4(i) can, (ii) can, (iii) cannot, (iv) can

The following statements are made about the involvement of the type III protein secretion system (T3SS) during bacterial pathogenesis in plants and animals.

1. A. It involves a protein complex that spans both the inner and outer bacterial membranes.
2. B. T3SS mostly secretes Avr effector proteins directly into plant apoplast.
3. C. The genes encoding conserved components of the T3SS of plant and animal pathogenic bacteria are referred to as Hrp (hypersensitive response and pathogenicity cluster).
4. D. Once Avr effectors are delivered inside the plant cell, Hrp proteins are not needed for the activation of the defence response.

Which one of the following options represents the combination of all correct statements?

1. 1A and C
2. 2B and C
3. 3A and D
4. 4B and D

The interconversion of fructose 6-phosphate to fructose 1,6-bisphosphate is a critical step in central metabolism in plants. Followings are certain statements regarding this interconversion.

1. A. Phosphofructokinase catalyzes the C6 phosphorylation of fructose 6-phosphate.
2. B. Plastid phosphofructokinase is activated by P_i while cytosolic phosphofructokinase is activated by phosphenolpyruvate.
3. C. Cytosolic fructose 1,6-bisphosphatase is strongly inhibited by fructose 2,6-bisphosphate.
4. D. Pyrophosphate-dependent phosphofructokinase catalyzes a reversible reaction of interconversion of fructose 6-phosphate to fructose 1,6-bisphosphate.

Which one of the following options is a combination of all correct statements?

1. 1A and B
2. 2B and D
3. 3A and C
4. 4C and D

The following statements were made about the alternative pathway of Complement activation in the immune system:

1. A. The pathway is initiated when antibodies bind to pathogen.
2. B. The pathway is initiated by spontaneous hydrolysis of serum Complement.
3. C. The pathway uses the same C3- and C5-convertases as the lectin pathway.
4. D. The pathway can be initiated by properdin and thrombin.

Which one of the following options represents the combination of all correct statements?

1. 1A and C
2. 2A and D
3. 3B and D
4. 4C and D

To study different DNA double-strand break (DSB) repair pathways, a construct is developed that contains a neomycin selectable marker gene flanked by two inactive GFP genes: the first one is inactivated by the insertion of an I-SceI recognition sequence, and the other one has a 99 bp deletion at the 5′ end of the gene. The induction of the I-SceI endonuclease will create a DSB in the first GFP sequence.

The following expected outcomes have been proposed:

1. A. If the DSB is repaired by the gene conversion (GC) pathway, cells will be GFP-positive and neomycin-resistant.
2. B. If the DSB is repaired by the GC pathway, cells will be GFP-positive but neomycin-sensitive.
3. C. If the DSB is repaired by the single-strand annealing (SSA) pathway, cells will be GFP-positive and neomycin resistant.
4. D. If the DSB is repaired by the non-homologous end joining (NHEJ) pathway, cells will be GFP-negative and neomycin resistant.

Which one of the following options represents the combination of all correct statements?

1. 1A, C and D
2. 2B, C and D
3. 3A and C only
4. 4A and D only

Presence of E-cadherin activates the Hippo pathway in the inner cell mass (ICM). Experimentally eliminating E-cadherin disrupts both apicobasal polarity and specification of the ICM and trophoectoderm lineages. Which one of the following schemes leads to pluripotency?

1. 1Scheme 1
2. 2Scheme 2
3. 3Scheme 3
4. 4Scheme 4

Some of the following statements describe nomenclature rules in the International Code of Zoological Nomenclature (ICZN).

1. A. If the generic name is of masculine gender, the species name should be of feminine gender.
2. B. A name is to be rejected if it is a tautonym or inappropriately describes a taxon’s character.
3. C. The name of an animal taxon cannot be rejected because it is identical with the name of another taxon which is not an animal.
4. D. Even if the taxon concerned is no longer classified as an animal, its name remains available.

Select the option that includes all statements representing currently accepted nomenclature rules of the ICZN.

1. 1A, B and D
2. 2B, C and D
3. 3A and B only
4. 4C and D only

The following table shows a list of migratory birds coming to India (Column X) and the region from where they migrate (Column Y).

Which one of the following options represents all correct matches between Column X and Column Y?

1. 1A-III, B-IV, C-I, D-II
2. 2A-II, B-III, C-I, D-IV
3. 3A-I, B-II, C-III, D-IV
4. 4A-II, B-III, C-IV, D-I

Angiotensin converting enzyme (ACE) converts angiotensin I into angiotensin II. ACE inhibitors should not be given to a person with severe loss of blood because:

1. A. these will increase renal tubular K⁺ excretion.
2. B. these will relax smooth muscles in the arteries.
3. C. these will reduce aldosterone secretion and thereby prevent water retention.
4. D. these will decrease renal tubular NaCl and water excretion.

Which one of the following options represents the combination of correct reasons?

1. 1A and C
2. 2A and D
3. 3B and C
4. 4B and D

The mechanisms of action of calcitropic hormones are important for understanding the molecular basis of disease states related to calcium homeostasis.

1. A. Calcium binding (transport) protein (CaBP) enhances the movement of calcium from the brush border into the cytoplasm.
2. B. Receptors for calcitonin are present in the osteoclasts where they increase cAMP production.
3. C. Parathormone essentially works independently to mobilize bone mineral, and never in concert with vitamin D.
4. D. The major calcitropic hormone, calcitriol, regulates intestinal calcium absorption.

Which one of the following options is INCORRECT in maintaining calcium homeostasis?

1. 1A and B
2. 2Only B
3. 3Only C
4. 4C and D

Match the following ribose sugar pucker in nucleic acids (labeled A, B, C, D) with their corresponding conformational states. The black circle denotes the base of the nucleotide.

1. 1A – C2′-exo; B – O4′-exo; C – C3′-endo; D – O4′-endo
2. 2A – C2′-endo; B – O4′-endo; C – C3′-endo; D – O4′-exo
3. 3A – C2′-endo; B – O4′-exo; C – C3′-exo; D – O4′-exo
4. 4A – C2′-exo; B – O4′-endo; C – C3′-exo; D – O4′-endo

The lipid composition of the two monolayers of the plasma membrane is quite different. This lipid asymmetry is functionally relevant, especially in converting extracellular signals into intracellular ones. Given below are a few membrane lipids:

1. A. Phosphatidylserine
2. B. Phosphatidylinositol 4-phosphate
3. C. Phosphatidylcholine
4. D. Sphingomyelin

Choose the option that correctly defines all the lipids involved in signaling and are restricted to the cytosolic face of the plasma membrane.

1. 1A only
2. 2A and B
3. 3C and D
4. 4C only

Given below is a list of microbes or their components (Column X) and specific stains (Column Y) used for their identification.

Which one of the following options represents the combination of all correct matches?

1. 1A-iv, C-iii, E-v
2. 2B-vi, F-ii, A-i
3. 3A-i, B-vi, F-vii
4. 4E-iii, C-v, D-i

With reference to the origin of multicellularity in different life forms, which one of the following statements is INCORRECT?

1. 1The ‘snowflake yeast’ experiment demonstrated the evolution of multicellularity through cell adhesion and programmed cell death.
2. 2The syncytial theory states that multicellular organisms arose through the aggregation of free-living unicellular forms.
3. 3Cadherin-based adhesion pathways played an important role in the evolution of multicellularity in plants.
4. 4Co-option of existing functions is hypothesized to have driven the evolutionary transition from undifferentiated multicellular clusters to differentiated tissues.

The absorbance values of a dye measured at 600 nm were plotted against its corresponding concentrations, as given below.

Which of the following will be the best estimate of the extinction coefficient of the compound in M⁻¹cm⁻¹ units? The path length of the cuvette used for the measurement is 1 cm.

1. 10.1
2. 20.033
3. 333.3
4. 4100

The phylogeny given below depicts the evolutionary relationships and branch lengths of species found in three spider communities, X, Y, and Z, along with a table showing their absence (0) and presence (1) in these communities.

Which one of the following options gives the correct values of phylogenetic diversity for these communities?

1. 1X=7.0, Y=4.5, Z=8.0
2. 2X=8.0, Y=6.0, Z=7.0
3. 3X=7.0, Y=4.0, Z=7.0
4. 4X=7.0, Y=3.5, Z=6.0

Evolution by natural selection may produce organisms that are adapted to their environment. Given below are four statements regarding adaptation by natural selection.

1. A. Adaptation implies that organisms are perfectly matched to their current environment.
2. B. Adaptive traits have been shaped by natural selection to past environments.
3. C. Natural selection is the only process by which adaptive traits evolve.
4. D. Adaptation to current environments may be constrained by adaptation to past environments.

Which one of the following options gives the correct combination of True/False statements?

1. 1A: True, B: False, C: True, D: False
2. 2A: True, B: True, C: True, D: False
3. 3A: False, B: True, C: False, D: True
4. 4A: False, B: False, C: False, D: True

Given below are recognition sites of some restriction enzymes with the sites of restriction marked with a ‘^’ symbol.

EcoRV : GAT^ATC; HindIII : A^AGCTT; SmaI : CCC^GGG; AvaI : C^YCGRG; SalI : G^TCGAC; XbaI : T^CTAGA

Which one of the following options represents all enzyme-treated vector (V) and insert (I) fragment combinations that would generate compatible ends for ligation without any other intermediate enzymatic treatment?

1. 1HindIII (V) – SalI (I); SmaI (V) – EcoRV (I)
2. 2SmaI (V) – XbaI (I); EcoRV (V) – HindIII (I)
3. 3HindIII (V) – SalI (I); XbaI (V) – AvaI (I)
4. 4EcoRV (V) – SmaI (I); AvaI (V) – SalI (I)

T cell precursors that exit the bone marrow undergo positive and negative selection in the thymus before emerging as mature T cells. These processes are controlled by cellular interactions of the thymocyte with stromal cells in the thymus. The following statements are made regarding the selection process:

1. A. The selection process involves negative selection of auto-reactive cells in the cortex followed by their migration to the medulla.
2. B. The selection process relies on the transcription factor ‘Aire’.
3. C. The selection process can lead to the generation of CD4 cells that can interact with dendritic cells (DCs) as well as B cells.
4. D. The selection process can lead to the generation of regulatory CD4 T cells.

Which one of the following options represents the combination of all correct answers?

1. 1A and B only
2. 2B and C only
3. 3B, C and D
4. 4A, B and D

Match the following bacterial gene expression mechanisms:

Which one of the following options represents all correct matches between Column X and Column Y?

1. 1A (iv), B (i), C (ii), D (iii)
2. 2A (i), B (iv), C (ii), D (iii)
3. 3A (iv), B (ii), C (i), D (iii)
4. 4A (ii), B (i), C (iv), D (iii)

Match the insects (Column X) to the insect orders (Column Y)

Select the option that correctly matches column X with column Y.

1. 1A-ii, B-iii, C-iv, D-v, E-i
2. 2A-iii, B-i, C-v, D-iv, E-ii
3. 3A-i, B-iv, C-ii, D-iii, E-v
4. 4A-iv, B-v, C-i, D-ii, E-iii

Consider a predator that can forage on two prey types, where Prey₁ is the more profitable prey and Prey₂ is the less profitable prey. While searching for Prey₁, if it encounters Prey₂, the decision to capture Prey₂ or ignore it and continue to search for Prey₁ is given by the predictions of the Optimal Foraging Theory (OFT). The table below gives various parameters that may be used as per OFT by the predator in making this foraging decision.

Which one of the following statements predicts correctly when the predator should eat Prey₂, given the conditions above?

1. 1Only when S₁ < [(E₁h₂) / E₂] − h₁
2. 2Only when S₁ > [(E₁h₂) / E₂] − h₁
3. 3Whenever S₂ < [(E₁h₂) / E₂] − h₁
4. 4Whenever S₂ > [(E₁h₂) / E₂] − h₁

A purified 150 kDa species obtained from a gel filtration column was run on a 2-dimensional SDS-PAGE as shown below:

What is the likely form of the 150 kDa species from this observation?

1. 1There are at least two proteins that are linked through non-covalent interactions.
2. 2There are at least two proteins in the complex that are linked through covalent bonds.
3. 3There are two proteins in the mixture without forming a complex.
4. 4There is only one protein and it has a disulfide bond.

Given below are a few ion transport proteins present on the membrane of pancreatic duct cells.

1. A. Cystic fibrosis transmembrane conductance regulator (CFTR)
2. B. Sodium-bicarbonate cotransporter (NBC)
3. C. K⁺ channel
4. D. Cl⁻/HCO₃⁻ exchanger

Which one of the following options represents the correct combinations of proteins located on the basolateral membrane of pancreatic duct cells?

1. 1A and B
2. 2B and C
3. 3C and D
4. 4A and D

Below is a table with the list of post-translational modifications on proteins and amino acid residues that are correspondingly modified.

Which post-translational modifications are correctly matched with the amino acid residues they typically modify?

1. 1A, B, and C
2. 2B, C, and D
3. 3C and D only
4. 4A and B only

In a study, researchers replaced the natural promoter of a gene with a synthetic promoter that contains a point mutation in the TATA box that prevents binding of the TATA-binding protein (TBP). The following outcomes would most likely result from this modification.

1. A. An mRNA will be generated with an alternate reading frame.
2. B. The mRNA will be transcribed by RNA polymerase I instead of RNA polymerase II.
3. C. Transcription may occur with a reduced efficiency.
4. D. Transcription may occur but will always result in the formation of a non-functional mRNA.

Which one of the following options represents the combination of all INCORRECT statements?

1. 1A and C only
2. 2A, B and D
3. 3A, C and D
4. 4B and D only

An ecologist calculates the Shannon-Wiener diversity index for an ecosystem with high species diversity. Which one of the following statements about this diversity index is INCORRECT?

1. 1It increases as species richness increases.
2. 2It is maximized when all species have equal abundances.
3. 3It is unaffected by the evenness of species abundances.
4. 4A low index value indicates dominance of one or a few species.

The figure below shows the genes (a, b, c, d, f, l, m, n) that are expressed in cell types 1, 2, and 3 because of the concentration of morphogen signaling received by these cells.

Which one of the following statements is correct about the pattern of gene expression induced by the morphogen?

The transcription factor activated by the morphogen has:

1. 1higher affinity for regulatory region of a than that of d.
2. 2higher affinity for regulatory region of f than that of c.
3. 3same affinity for regulatory regions of a and b.
4. 4lower affinity for regulatory region of m than that of c.