CSIR-NET Life Sciences June 2024 Question Paper (Shift 1) with Answer Key and Solutions

In humans, if both parents are of blood group AB, then, there is a 1/4 probability that their offspring will be of blood group A, and 1/2 probability that the offspring will be of blood group AB. If the couple have three children, what is the probability that NONE of the children will be of blood group A or AB?

1. 11/4
2. 23/4
3. 31/64
4. 463/64

Every element in the central column of the matrix has a simple arithmetic relationship with the pairs on the left and right in the corresponding row.

What would be the value of X?

1. 12
2. 21
3. 30
4. 4−1

For any four consecutive decimal digits, the largest value of the product of the sum of any two and the sum of the other two is

1. 1an even number and a perfect square
2. 2an even number, but not a perfect square
3. 3an odd number and a perfect square
4. 4an odd number, but not a perfect square

A record player stylus moves along a spiral groove cut on an annular portion of a disc. A record with inner radius 4 cm and outer radius 10 cm of the annulus, turning 100 times plays for 22 minutes. During this time the stylus travels at an average linear speed that is approximately equal to

1. 1100 m/h
2. 2120 m/h
3. 3220 m/h
4. 4440 m/h

Consider the first few consecutive natural numbers. The ratio of the sum of their squares to their sum can NEVER be

1. 167
2. 275
3. 391
4. 4100

If 16x² − 25y² + 7 = 0, x and y being positive numbers, then which of the following may hold?

1. 14x + 5y + 1 = 0
2. 24x + 5y + 7 = 0
3. 34x − 5y + 1 = 0
4. 44x − 5y − 7 = 0

Among five girls standing side by side, Leela has exactly one girl to her left, Alice is just right of Prerna, and there are at least two girls between Radha and Zarina. The girl in the middle is

1. 1Prerna
2. 2Alice
3. 3Leela
4. 4Zarina

Suppose liars always lie and truthful persons never. In a group of 4 people A, B, C and D, A says, “We’re all liars”, B says, “Only one of us is a liar”, C says, “No, exactly two of us are liars” and D says, “I’m truthful”. Which among the following is definitely FALSE?

1. 1A is a liar
2. 2B is a liar
3. 3C is a liar
4. 4D is a liar

The growth model for a population is N_t = N₀ e^rt, where N_t is the population at time t, N₀ is the initial population and r is the per capita growth rate. How long does it take for the population numbers to double?

1. 1(ln 2)/r
2. 22/r
3. 31/(r ln 2)
4. 41/r

A straight irrigation canal in a plain area has a floor at a depth of 5 m from the surface. The canal is 20 m wide at the surface. The floor of the canal is flat and the embankments have a slope of 45°. When it is completely filled, what will be the volume of water (in m³) in the canal over a length of 100m?

1. 16000
2. 27500
3. 38000
4. 49500

If X > Y > 0, then X% of Y is

1. 1equal to Y% of X
2. 2more than Y% of X
3. 3less than Y% of X
4. 4(X + Y)% of (X + Y)

A certain item of raw food contains 35% starch, 25% protein, the rest fibre. The item is cooked by boiling in water, which doubles its weight. Half of the fibre in the food becomes soluble when cooked. If the cooked item weighs 200g, the amount of soluble fibre in it is

1. 115 g
2. 230 g
3. 320 g
4. 440 g

A ball starts rolling from the edge of the slope at time t = 0 as shown in the diagram.

Referring to the graphs A, B, C, which of the following statements is correct?

1. 1A depicts motion with friction while C depicts motion without friction
2. 2C depicts motion with friction while A depicts motion without friction
3. 3B depicts motion with friction while A depicts motion without friction
4. 4B depicts motion with friction while C depicts motion without friction

The graph shows average run rate (runs scored per over) by teams A and B in a twenty overs cricket match.

Select the INCORRECT statement.

1. 1Team B scored more runs than team A in the first 10 overs.
2. 2Team A scored more runs than team B in all.
3. 3Team B scored more runs in overs 1–10 than in overs 11–20.
4. 4Team A has a lower overall run rate than team B.

A spherical object of radius 6 cm was melted and cast into a cylindrical bar of radius 3 cm. What would be the length (in cm) of the bar?

1. 124
2. 232
3. 336
4. 442

The total monthly income of a family is split into expenses on food (F), house rent (H), college fees (C), entertainment (E), miscellaneous items (M), and savings (S), as shown in the pie chart.

The family transfers an amount of Rs 1000/- from the head food to the head entertainment, thereby making the expenses on the two heads equal. What is the net expenditure of the family?

1. 1Rs 20,000
2. 2Rs 50,000
3. 3Rs 37,500
4. 4Rs 17,000

A 1 m long rod having diameter of 12 mm weighs 880 g. What, approximately, is the density (in g/cm³) of the material of the rod?

1. 16.2
2. 26.6
3. 37.8
4. 48.8

Choose the option that will make the following statement FALSE:

A CHILD COUNTED THE NUMBER OF APPEARANCES OF THE LETTER T IN THIS SENTENCE, AND REPORTED IT CORRECTLY AS ________.

1. 1TEN
2. 2ELEVEN
3. 3TWELVE
4. 4THIRTEEN

The chart shows forest cover as percentages of total areas of 6 countries over the period 1990-2022 and their land areas (in million km²).

The maximum change in forest area in absolute terms among these countries took place in

1. 1Tanzania
2. 2Russian Federation
3. 3India
4. 4China

A group of 54 boys and girls was made to stand in a queue as follows: a boy at the start was followed by a girl, then a boy followed by 2 girls, then a boy followed by 3 girls, and so on. The number of boys in the group was

1. 18
2. 29
3. 310
4. 427

A plant is NOT watered for seven days (day 1 – day 7). Leaf and root water potential are measured every two hours starting from day 1 till day 7. Which one of the following is LEAST LIKELY to happen?

1. 1Pre-dawn leaf water potential declines over the 7 days.
2. 2Leaf water potential shows a diurnal cycle of highs and lows.
3. 3Root water potential falls below leaf water potential at night.
4. 4Root water potential fluctuates between day and night.

Which of these traits is NOT characteristic of r-selected tree species?

1. 1Mortality and reproduction are strongly dependent on population density.
2. 2Tend to occupy habitats that are unpredictable and/or ephemeral.
3. 3Thrive in habitats where resource competition is low.
4. 4Have superior capabilities to colonize new habitats.

Which one of the following neurotransmitters is synthesized in synaptic vesicles instead of being transported to the vesicle after its synthesis in the cytoplasm?

1. 1Norepinephrine
2. 2Epinephrine
3. 3Acetylcholine
4. 4Serotonin

Which one of the following statements for the lac operon in E. coli is INCORRECT?

1. 1The lac operon is controlled by both the Lac repressor and the activator protein, CAP.
2. 2The lac operon is highly expressed only when both lactose and glucose are absent.
3. 3The lac operon is highly expressed only when lactose is present and glucose is absent.
4. 4In the presence of lactose, the repressor cannot bind to the operator.

Which one of the following statements about the cortical reaction in sea urchins is correct?

1. 1The entry of Ca²⁺ ions into the egg initiates development.
2. 2The exocytosed cortical granules during egg maturation contain the components of the zona pellucida.
3. 3The depolarization of the plasma membrane after sperm entry helps to block polyspermy.
4. 4The release of the cortical granules after sperm entry converts the vitelline membrane into the fertilization membrane which blocks polyspermy.

Who experimentally demonstrated “Mutations occur randomly”?

1. 1Alfred Hershey and Martha Chase
2. 2Matthew Meselson and Franklin Stahl
3. 3Salvador Luria and Max Delbrück
4. 4François Jacob and Jacques Monod

A community of woody plants is being shaped by environmental filtering. What will be the likely local species pool of this community, if the regional species pool comprises 60 species?

1. 1100
2. 280
3. 3120
4. 430

Which one of the following is an example of dishonest signaling?

1. 1Batesian model
2. 2Batesian mimic
3. 3Mullerian model
4. 4Mullerian mimic

How many amino acids are present in calcitonin, a calcium lowering hormone synthesized from C-cells of the human thyroid gland?

1. 142
2. 232
3. 322
4. 412

Which of the following is LEAST suited for long-distance phloem transport of photo-assimilated carbon in plants?

1. 1Reducing sugars
2. 2Mannitol
3. 3Galactosyl-sucrose oligosaccharides
4. 4Non-reducing sugars

Cell lysate in 1% TX100 was purified over an affinity column to isolate a complex with certain enzymatic activity. The purified enzyme complex was separated on a 10-50% continuous sucrose gradient. Shown below are the UV spectra using an absorbance filter at 280nm or 260nm.

Which one of the following combinations of molecules would generate the spectra shown above?

1. 1Protein-Protein
2. 2Protein-RNA
3. 3Protein-Lipid
4. 4Protein-Cholesterol

A researcher overexpresses the full-length genomic sequence of rice GAPDH gene under a CaMV35S promoter in transgenic rice. Which one of the following options can be used to confirm transgenic lines using PCR?

1. 1Using exon-specific primers of the GAPDH gene.
2. 2Using intron-specific primers of the GAPDH gene.
3. 3Amplification of the promoter region of the GAPDH gene.
4. 4Using CaMV35S promoter-specific forward and GAPDH-specific reverse primer.

Which one of the following is a correct combination of four carbon intermediates formed during C4 photosynthesis in plants?

1. 1Malate and Aspartate
2. 2Aspartate and Alanine
3. 3Phosphoenolpyruvate and Oxaloacetate
4. 4Alanine and Pyruvate

It was found that most people who were vaccinated with the ancestral strain of Covid-19 (Wuhan strain) were protected against the Delta variant but not against the Omicron variant. PBMCs (peripheral blood mononuclear cells) and serum were obtained from five successfully vaccinated individuals with good neutralizing antibody titres and cytotoxic (CTL) activity against the Wuhan strain-infected targets. Pooled serum was transferred into unrelated recipient “A” and pooled purified T cells were transferred into unrelated recipient “B”. Which one of the following is likely to be observed?

1. 1“A” will be protected against both the ancestral strain and the Delta variant.
2. 2“B” will be protected against ancestral strain but not against the Delta variant.
3. 3“A” will be protected against infection with the Omicron variant.
4. 4“A” will make antibodies against interferon gamma present in the donor serum.

Which one of the following statements regarding plasmodesmata in a plant cell is INCORRECT?

1. 1They are specialized cell-to-cell junctions.
2. 2They are open channels that connect the cytosol of adjacent cells.
3. 3The plasma membranes of the adjacent cells extend continuously through each plasmodesma.
4. 4Plasmodesmata are extensions of chloroplast that interconnects the cytosol of the adjacent cells.

In eukaryotes, nucleosome remodelers

1. 1methylate histone H3.
2. 2acetylate histone H3 and H4.
3. 3create DNaseI hypersensitive sites.
4. 4degrade histone subunits.

A pulse oximeter measures the ratio between oxyhemoglobin and hemoglobin in the pulsating condition on the finger. Which combination of wavelengths can obtain a differential absorption to measure blood oxygen saturation?

1. 1Ultraviolet and Infrared
2. 2Visible and Infrared
3. 3Far-ultraviolet and visible
4. 4Ultraviolet and far-ultraviolet

Which one of the following statements regarding mammalian innate immunity is INCORRECT?

1. 1Pattern recognition receptors (PRRs) are a component of innate immunity.
2. 2Serum complement proteins are part of innate immunity.
3. 3Innate immunity has only a narrow range of specificity.
4. 4The outcome of innate immunity is the rapid recognition and phagocytosis or destruction of the pathogen.

A student counts the number of seeds produced by ten different haploid Arabidopsis plants and obtains the following data:

0, 5, 15, 25, 100, 150, 200, 600, 1500, 3000.

Which one of the following is the best measure of central tendency for summarizing the above data?

1. 1Mean
2. 2Median
3. 3Mode
4. 4Standard deviation

A DNA molecule is completely transcribed into messenger RNA by an RNA polymerase. The base composition of the DNA template strand is G = 24.1%; C = 18.5%; A = 24.6%; T = 32.8%. The base composition of the newly synthesized RNA molecule is:

1. 1G = 24.1%, C = 18.5%, A = 24.6%, U = 32.8%
2. 2G = 24.6%, C = 24.1%, A = 18.5%, U = 32.8%
3. 3G = 18.5%, C = 24.1%, A = 32.8%, U = 24.6%
4. 4G = 32.8%, C = 24.6%, A = 18.5%, U = 24.1%

In the representation of the di-peptide shown below, the superscript ‘-1’ denotes the atom of the previous amino acid while ‘+1’ denotes the atom of the next amino acid.

The atomic coordinates of how many AND which of the following atoms are required to uniquely define the torsion angles, ϕ and ψ of the Ramachandran plot?

1. 14 atoms; C⁻¹, N, C^α, C for ϕ; N, C^α, C, N⁺¹ for ψ
2. 22 atoms; N and C^α for ϕ; C^α and C for ψ
3. 34 atoms; H, N, C^α, C for ϕ; N, C^α, C, O for ψ
4. 43 atoms; C⁻¹, N, C^α for ϕ; C^α, C, N⁺¹ for ψ

What is the correct order in which the following proteins are recruited during DNA double strand break repair in prokaryotes?

1. 1RecA, RecBCD, Ssb, DNA Pol III, DNA Ligase
2. 2Ssb, RecA, RecBCD, DNA Pol III, DNA Ligase
3. 3RecBCD, RecA, Ssb, DNA Pol III, DNA Ligase
4. 4RecBCD, Ssb, RecA, DNA Pol III, DNA Ligase

Retinal rod cell cGMP-phosphodiesterase is an enzyme with subunit structure as:

1. 1αβγ
2. 2αβγ2
3. 3αβ2γ
4. 4α2βγ

Which one of the following concepts can explain host-parasite co-evolution?

1. 1Kin selection
2. 2Red Queen hypothesis
3. 3Runaway selection
4. 4Handicap principle

If chimeric mouse embryos were generated using GFP-expressing embryonic stem cells and RFP-expressing induced pluripotent stem cells, which one of the following tissues from any resulting embryos will not express any fluorescent protein?

1. 1Brain
2. 2Heart
3. 3Intestine
4. 4Placenta

Which one of the following correctly describes ‘Dark Reversion’ of phytochromes?

1. 1Conversion of P_R to P_FR
2. 2Conversion of P_FR to P_R
3. 3Export of P_FR from cytosol to nucleus
4. 4Export of P_R from cytosol to nucleus

For maintaining hydraulic conductance, tree stems appear to trade-off vessel diameter with

1. 1strength of the stem.
2. 2stem length.
3. 3heartwood volume.
4. 4vessel length.

Andaman and Nicobar archipelago are part of which biodiversity hotspots?

1. 1Andaman – Indo-Burma; Nicobar – Sundaland
2. 2Andaman – Sundaland; Nicobar – Indo-Burma
3. 3Andaman – Indo-Burma; Nicobar – Indo-Burma
4. 4Andaman – Sundaland; Nicobar – Sundaland

Select the statement that describes guild coevolution, also known as diffuse coevolution.

1. 1One species uses the other as a resource.
2. 2Two species coevolve reciprocally, but only to each other.
3. 3Several species are involved in coevolutionary interactions.
4. 4A species escapes association from a predator and diversifies. Later, a different predator adapts to the host and diversifies.

Which one of the following statements regarding the structure of water molecule is correct?

1. 1The oxygen atom in water is in sp³ hybridization, with an H-O-H angle of 109.5°.
2. 2The oxygen atom in water is in sp² hybridization, with an H-O-H angle of 120°.
3. 3The oxygen atom in water is in sp³ hybridization, with an H-O-H angle of 104.5°.
4. 4The oxygen atom in water is in sp² hybridization, with an H-O-H angle of 90°.

Given below are Ramachandran plots for four different proteins.

Choose the correct pair of proteins, both of which are predominantly alpha helical in nature.

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

In Caenorhabditis elegans, blastomere identity occurs both through conditional and autonomous modes of cell specification. Which one of the following options is a correct statement in this regard?

1. 1If the AB and P1 blastomeres are experimentally separated, the AB cell will generate all cells it would normally make.
2. 2When AB divides to form daughter cells, ABp becomes different from ABa through its interaction with the P2 cell.
3. 3The specification of AB cell is determined by the presence of cytoplasmic determinants.
4. 4The P2 cell produces a morphogen for the determination of the ABp cell.

Which one of the following options has the correct set of components for assaying reverse transcriptase activity?

1. 1RNA primer, dNTPs, buffer, primase, DNA template
2. 2DNA primer, NTPs, buffer, DNA template
3. 3DNA primer, dNTPs, buffer, RNA template
4. 4RNA primer, NTPs, buffer, RNA template

In eukaryotic cells, DNA replication is restricted to the S phase of the cell cycle because

1. 1DNA polymerase is present only in the S phase of the cell cycle.
2. 2Origin recognition complex (ORC) recognizes origin only in the S phase.
3. 3MCM helicases get activated in the S phase of the cell cycle.
4. 4MCM helicases get activated in the G1 phase of the cell cycle.

Which one of the following does NOT occur during ribosome-associated quality control of damaged mRNA?

1. 1mRNA degradation
2. 2Nascent protein degradation
3. 3Disengagement of ribosome from mRNA
4. 4Ribosome-mRNA monosome degradation

In which one of the following stages pontogeniculo-occipital (PGO) spikes are found in human EEG recordings?

1. 1Immediately before and during REM sleep
2. 2Non-REM sleep stage 2
3. 3Awake condition
4. 4Non-REM sleep stage 4

Which one of the following statements correctly explains the function of a GTPase activating protein (GAP) in the regulation of heterotrimeric G proteins in plants?

1. 1It activates Gβ protein.
2. 2It inactivates Gα protein.
3. 3It directly inhibits ligand binding to GPCR.
4. 4It leads to the dissociation of Gα from Gβ/Gγ subunits.

The following are sketches of wild-type and mutant (I – III) embryos of Drosophila melanogaster.

Which one of the following options represents a correct match between the gene and its loss of function phenotype?

1. 1dorsal : I
2. 2torpedo : III
3. 3gurken : II
4. 4cactus : III

Select the correct combination of terms from plant breeding systems that represents selfing or promote selfing.

1. 1Autogamy and allogamy
2. 2Cleistogamy and geitonogamy
3. 3Geitonogamy and allogamy
4. 4Autogamy and herkogamy

Which one of the following statements regarding principles of linkage mapping in plants is correct?

1. 1Genetic markers would always show higher recombination frequencies when they are closer to each other than if they are far apart.
2. 2The genetic distance between two markers is a true representation of the physical distance between them.
3. 3An ideal mapping population for a self-pollinating species is generated using polymorphic parents that are inbred lines.
4. 4An F₂ mapping population would segregate in a 1:2:1 ratio for a dominant marker.

In rate-zonal centrifugation, a mixture is spun just long enough to separate molecules that differ in mass but may be similar in shape and density. Which one of the following options represents the component that is typically used to create a gradient in this technique?

1. 1phospholipids
2. 2sucrose
3. 3KCl
4. 4starch

Which one of the following options includes all plants that are major non-native invaders of aquatic ecosystems in India?

1. 1Parthenium hysterophorus, Pontederia crassipes, Lantana camara
2. 2Salvinia molesta, Prosopis juliflora, Mikania micrantha
3. 3Nelumbo nucifera, Pogostemon erectus, Hygrophila serpyllum
4. 4Pontederia crassipes, Salvinia molesta, Alternanthera philoxeroides

How many times are sound waves amplified in the middle ear of a human?

1. 116 – 18
2. 26 – 8
3. 39 – 12
4. 42 – 4

Select the geological time where some of the major events, like an increase in marine diversity, dominance of gymnosperms, diversification of synapsids (including the emergence of first dinosaurs), and first mammal-like forms, occurred.

1. 1Cretaceous
2. 2Jurassic
3. 3Triassic
4. 4Carboniferous

Which one of the following activities is associated with Mitochondria-associated ER membranes (MAM)?

1. 1Protein glycosylation
2. 2ATP synthesis
3. 3Phospholipid metabolism
4. 4Iron-sulphur cluster assembly

In animal cells, typically which organelle is only provided by the sperm to the oocyte following fertilization?

1. 1Nucleolus
2. 2Peroxisomes
3. 3Mitochondria
4. 4Centrioles

Brassica juncea has bisexual flowers.

A mutation in the mitochondria leads to cytoplasmic male sterility (CMS). CMS can be restored by a restorer of fertility gene (Rf) which is a nuclear gene.

Fertility restoration is a dominant phenotype.

A CMS line is crossed to a homozygous Rf line. The obtained F₁ progeny is self-pollinated. What percentage of F₂ progeny will be male sterile?

1. 10
2. 225
3. 375
4. 4100

Which one of the following represents the predominant ‘source organ’ during phloem translocation in healthy plants?

1. 1Roots
2. 2Developing fruits
3. 3Immature leaves
4. 4Mature leaves

In 2007, scientists reported the fossil of a deer-like animal in Kashmir, India which is considered the most recent terrestrial ancestor of whales. The name of this fossil is

1. 1Jainosaurus.
2. 2Indohyus.
3. 3Rajasaurus.
4. 4Indosuchus.

Which one of the following pairs correctly matches the enzyme with its allosteric activator?

1. 1Phosphofructokinase : Citrate
2. 2Pyruvate dehydrogenase : NADH
3. 3Pyruvate carboxylase : ADP
4. 4Pyruvate kinase : Fructose-1,6-bisphosphate

The interpretation of any clinical laboratory test is done by comparing the patient’s results to the test’s reference intervals. For example, the reference interval for white blood cells (WBC) in human adults is 4,500 – 11,000 cells/microlitre. Estimation of this reference interval is done by testing

1. 1a large number of healthy adults and estimating the range between 2.5 to 97.5 percentiles of the reference population.
2. 2a large number of healthy adults and estimating the range between 5 to 95 percentiles of the reference population.
3. 3a large number of random adults and estimating the range between 5 to 95 percentiles of the reference population.
4. 4a large number of random adults and estimating the range between -1.64 and +1.64 standard deviations either side of the mean of the reference population.

Cystic fibrosis is caused by a recessive allele. Roughly one out of every 500 individuals (0.20%) have this disease. Using the Hardy-Weinberg equation, the percentage of individuals who are carriers of the recessive allele for the disease is

1. 110.2
2. 21.0
3. 315.2
4. 47.6

The Ran GTPase imposes directionality on transport through nuclear pore complexes (NPCs). Like other GTPases, Ran is a molecular switch that can exist in two conformational states, depending on whether bound to GDP or GTP. Possible reasons for compartmentalization of Ran-GTP accumulation are:

1. A. Ran-GAP is enriched in the nucleus
2. B. Ran-GAP is localized in the cytosol
3. C. Ran-GEF is enriched in the nucleus
4. D. The nuclear import receptors help in the compartmentalization of Ran-GTP

Which of the options below has all the correct statements about Ran-GTP compartmentalization?

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

During physical exercise, a large amount of oxygen is delivered to the active muscles by many physiological adjustments including a change in the P₅₀ value (which is determined by P_O2 at which hemoglobin is half-saturated with oxygen). The following proposed statements explain the mechanism of change in P₅₀ during exercise:

1. A. P₅₀ is increased during exercise as the temperature rises in active muscles.
2. B. During exercise, metabolites accumulate in the active muscles resulting in higher pH that increases P₅₀.
3. C. P₅₀ is increased during exercise as CO₂ is decreased in active muscles.
4. D. An increase in 2,3-DPG has been reported in non-trained person within 60 min of exercise resulting in higher P₅₀.

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

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

Given below are a few statements regarding the rate of glycolysis, gluconeogenesis and glycogen metabolism.

1. A. Increased blood glucose would decrease gluconeogenesis and increase glycogen synthesis.
2. B. Increased levels of fructose-1, 6-bisphosphate inhibits glycolysis.
3. C. Increased blood glucagon inhibits glycogen synthesis and stimulates glycogen break down.
4. D. Increase in AMP levels inhibits glycolysis and stimulates gluconeogenesis.

Which one of the following options represents INCORRECT statements?

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

In a line transect of length L and half-width w, designed for estimating the density of gaur (~ D=N/2Lw), N animals were counted.

The following statements represent possible assumptions about population sampling.

1. A. The probability of detection is independent of distance from the transect line.
2. B. The animals in question are uniformly distributed through the study area.
3. C. The animals are deemed to be stationary and thus detected only once during the sampling.
4. D. Animals on the line will be detected with a probability equal to 1.

Select the options that are considered as assumptions in line transect sampling.

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

Biosynthesis of glutamine and asparagine is sensitive to light and to the availability of reduced carbon. Following are a few statements regarding the same.

1. A. Expression of the plastid-localized Glutamine Synthetase (GS) gene is upregulated by light.
2. B. Darkness promotes the expression of Asparagine Synthetase (AS) gene.
3. C. Expression of GS is inhibited by sucrose while that of AS is upregulated by sucrose.
4. D. Asparagine is a more efficient carbon source than glutamine.

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

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

Given below are a few statements on transgenic plants.

1. A. Transgenic plants generated using a transformation vector with the CaMV35S promoter-GUS-35SpA cassette can show variations in expression levels of GUS protein in independent transgenic events due to differences in strength of promoter used to express the GUS gene.
2. B. A transgenic plant containing two insertions of the transgene cassette as inverted repeats in tandem would segregate in a 3:1 ratio for the transgenic phenotype on backcrossing the transgenic plant with the untransformed parent.
3. C. A transgene containing a potential polyadenylation signal in its coding sequence would generate full-length transgene mRNA but a truncated transgenic protein.
4. D. A gene-pyramiding experiment to bring together two transgenic traits by crossing independent homozygous single-copy transgenic lines for each trait would produce a plant homozygous for both the transgenes in the F₂ generation.

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

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

Given below are a few statements related to enzymes and their functions in molecular reactions.

1. A. Alkaline phosphatases remove 3’ phosphates from DNA and RNA.
2. B. S1 nuclease removes single-stranded regions from partially double-stranded DNA.
3. C. 5’ end-labelling of DNA molecules can be done by using polynucleotide kinase which transfers a ³²P-labelled phosphate group to the 5’ end of dephosphorylated DNA.
4. D. 3’-5’ exonuclease activity of Taq polymerase releases the reporter from the 3’ end of Taqman probes in qPCR.

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

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

Phylogenetic trees are used to examine

1. A. relatedness among different populations, species or genera.
2. B. similarity in characters among different populations, species or genera.
3. C. common ancestry among different populations, species or genera.
4. D. functional significance of traits in populations, species or genera.

From the above statements, select the correct combination of statements that best represent the utility of phylogenetic trees.

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

Following are certain statements regarding Crassulacean Acid Metabolism (CAM) plants:

1. A. The HCO₃⁻ concentration is enriched in the cytosol during night by the CO₂ coming from the external atmosphere through the open stomata and the mitochondrial respiration.
2. B. Oxaloacetate produced by the action of PEPCase is stored in the vacuole during dark.
3. C. During light, oxaloacetate produces malate that provides CO₂ for Calvin-Benson cycle in the chloroplast.
4. D. During dark, phosphoenolpyruvate is produced by the breakdown of starch present in the chloroplast.
5. E. CAM is a mechanism of concentrating CO₂ around Rubisco by keeping stomata closed during day.

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

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

In order to investigate the involvement of the following proteins in the mismatch repair mechanism (MMR), an in vitro reconstitution experiment was performed. A 5’-nicked circular DNA substrate having a C:C mismatch at the PstI site was incubated with different combination of proteins (as shown below), where upon the repair of C:C mismatch, the PstI site will be regenerated. Following the incubation, the resulting DNA were digested with PstI and ScaI restriction endonucleases, and the products were electrophoresed in 0.8% agarose gel.

Based on the results obtained identify the INCORRECT statement.

1. 1Msh2-Msh6 complex is required for the repair of the C:C mismatched DNA.
2. 2Polδ and Msh2-Msh6 complex are necessary for the repair of the C:C mismatched DNA.
3. 3Polδ and Msh2-Msh6 complex are sufficient for the repair of the C:C mismatched DNA.
4. 4ExoI and Rad27 are redundant to each other for the repair of the C:C mismatched DNA.

Which one of the following options represents a classical Hoogsteen base pairing?

1. 1anti A base-paired with anti T
2. 2anti G base-paired with anti C
3. 3syn A base-paired with anti T
4. 4anti G base-paired with anti U

SLN1 receptor, a part of a two-component system, is required for osmoregulation in yeast. The yeast mutant (sln1) lacking the SLN1 receptor protein dies. A researcher tries to rescue the mutant by expressing an Arabidopsis gene for the cytokinin receptor, CRE1, which like SLN1 is also a histidine kinase that acts through a two-component system.

The following statements are made regarding the outcome of the experiment.

1. A. SLN1 and CRE1 proteins respond to the same external signals and therefore, CRE1 rescues the yeast mutant.
2. B. As CRE1 cannot interact with the downstream signaling pathway in the yeast, it will not rescue the yeast mutant.
3. C. CRE1 will rescue the yeast mutant, only if cytokinin is present.
4. D. The effector domains of CRE1 and SLN1 proteins are sufficiently similar and therefore, CRE1 can induce the downstream signaling pathway and rescue the yeast mutant.

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

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

A student used the mark-recapture method to assess the population size of grasshopper in a field. The student was asked to repeat the recapture procedure once on three consecutive days. The procedure followed by the student and the observations made are as follows:

• On day one, 40 grasshoppers were captured, marked and released back in the field.

• On day two, 60 grasshoppers were re-captured of which, 4 were marked. He marked the unmarked ones and released all 60 in the field.

• On day three, 50 grasshoppers were re-captured of which 7 were marked. He marked the unmarked ones and released all 50 in the field.

• On day four, 25 grasshoppers were re-captured of which 6 were marked.

The student was asked to calculate the population size based on the mean of the three observations. The estimated population size is:

1. 1600
2. 2~622
3. 3~351
4. 4~454

The following statements have been made regarding cell specification in an early embryo:

1. A. The entire embryo rarely interacts with its environment, and its developmental trajectory cannot be guided by its immediate “ecosystem”.
2. B. When cells are removed, changes in cellular biochemistry and function are never preceded by a process involving the commitment of the cell to a certain fate.
3. C. The fate of a cell or a tissue in the intact embryo is said to be specified when it is not capable of differentiating autonomously on being placed in a neutral environment, such as a petri dish or test tube.
4. D. If cells are removed, the interactions of the remaining cells compensate the fate of the removed cells, because the fate of a cell depends upon the conditions in which the cell finds itself.

With regard to the experiment shown below, where removal of cells from an early blastula leads to normal development of the larval form, which one of the above combination of statements apply to the development of the organism?

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

Sucrose-phosphate synthase (SPS) is a key enzyme in the biosynthesis of sucrose in plants. Following are certain statements regarding SPS:

1. A. Uridine-diphosphate glucose and fructose-6-phosphate are the substrates for SPS.
2. B. SPS directly converts its substrate into sucrose.
3. C. Phosphorylation activates while dephosphorylation inactivates SPS.
4. D. SPS converts its substrate into sucrose-6-phosphate which is then converted to sucrose by the action of sucrose-phosphate phosphatase.
5. E. Glucose 6-phosphate activates while Pi inactivates SPS.

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

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

Given below are the blood clotting factors in column X and their names in column Y.

Which of the following combination is a correct match of the factor with its name.

1. 1a-iv, b-iii, c-i, d-ii
2. 2a-ii, b-iii, c-i, d-iv
3. 3a-ii, b-i, c-iv, d-iii
4. 4a-i, b-ii, c-iv, d-iii

In vivo interaction between FLAG-tagged protein P and chaperone H was examined by co-immunoprecipitation (co-IP). Co-chaperone A was included and the co-IP was performed in the presence or absence of cycloheximide (CHX). The results of the co-IP experiments are shown below.

Which of the following interpretations from these experiments is INCORRECT?

1. 1Protein P interacts with chaperone H and co-chaperone A.
2. 2Chaperone H interacts only with the newly synthesized protein P.
3. 3Interaction between co-chaperone A and protein P is independent of chaperone H.
4. 4Interaction between chaperone H and protein P is independent of co-chaperone A.

Overexpression of protein ‘A’ in the brain of Drosophila melanogaster causes the degradation of ovaries in the animal. Overexpression of a secretion-incompetent allele of ‘A’ does not cause this phenotype. However, downregulation of protein ‘B’ in ovaries concomitant with overexpression of protein ‘A’ in the brain prevents ovary degradation. ‘A’ and ‘B’ are found to physically interact in ovary lysates. In the light of the above experiments, which of the following inferences would be correct?

1. 1The protein ‘A’ cell autonomously influences ovary development while B is secreted to influence brain function.
2. 2‘A’ is a ligand secreted from the brain and ‘B’ is a receptor in ovaries.
3. 3‘A’ is a neurotransmitter secreted from the brain and ‘B’ is a signal transducer in the ovaries.
4. 4‘A’ is a receptor secreted from the ovaries and ‘B’ is a ligand in the ovary cell membrane.

In the classic ABCDE model of flower development, different combinations of ABCDE class genes result in different whorls of organs. Which one of the following models would likely give rise to unisexual flower structures?

1. 1Model 1
2. 2Model 2
3. 3Model 3
4. 4Model 4

An ecological community is more than just the sum of the attributes of the constituent species. Which one of the following options is NOT an attribute of ecological communities?

1. 1Local extinction of a species caused by demographic stochasticity.
2. 2Logseries species abundance distributions.
3. 3Stability of a food web in the face of disturbance.
4. 4The limits to similarity of competing species.

Some features mentioned below are important for the segregation of homologous chromosomes in meiosis I.

1. A. Synaptonemal complex formation between homologous chromosomes.
2. B. Degradation of cohesins at the chromosome arms.
3. C. Retention of cohesins at the centromeres.
4. D. Bi-orientation of kinetochores of sister chromatids.

Which one of the following options has all correct features?

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

The following statements are made for the effect of hormones on the glomerular filtration rate (GFR).

1. A. Norepinephrine, epinephrine, and endothelin constrict renal blood vessels and decrease GFR.
2. B. Endothelin dilates renal blood vessels to increase GFR.
3. C. Norepinephrine and endothelin constrict renal blood vessels and decrease GFR, while epinephrine dilates renal blood vessels to increase GFR.
4. D. Prostaglandin (PGE₂) and bradykinin decrease renal vascular resistance and increase GFR.

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 hypothetical organism, at a four-celled embryonic stage, blastomere ‘X’ instructs one of the daughter cells of an adjoining blastomere ‘Y’ to take the fate ‘Ya’. The other daughter cell takes the fate ‘Yp’. This is illustrated in the figure below as lineages for Ya and Yp. If the X blastomere is removed, both daughter cells take up the Yp fate.

This instruction is mediated by a paracrine factor, Pap2 secreted by X blastomere interacting with Pap5 present on the membrane of Y blastomere.

The following experimental manipulations were carried out, which involved creating partial genetically mosaic embryos in vitro and following the fate of the Y blastomere.

Which one of the mosaics will show a developmental pattern similar to that when blastomere X is removed?

1. 1X blastomere null for Pap2 and wild type Y blastomere
2. 2Wild type X blastomere and constitutively activated Pap5 Y blastomere
3. 3X blastomere null for Pap2 and constitutively activated Pap5 Y blastomere
4. 4X blastomere null for Pap5 and wild type Y blastomere

The CDS of the shortest isoform of human gene ‘A’ is cloned into a 3.3 kb vector under a CMV promoter at the BamHI and XhoI sites (pCMV-A vector).

From the agarose gel and SDS-PAGE images shown above, which one of the following is most likely true for protein A in HeLa cells:

1. 1Protein A forms homo-multimers.
2. 2Protein A is degraded by the lysosome.
3. 3Protein A is polyubiquitinated.
4. 4Protein A localizes to autophagosomes.

A researcher used CRISPR-Cas9 system and observed a different type of mutation in two alleles of a target gene in a T₀ transgenic plant. These mutations are designated as follows:

Allele 1: addition of a nucleotide

Allele 2: deletion of a nucleotide

The observed mutations can be classified as

1. 1monoallelic mutations.
2. 2biallelic heterozygous mutations.
3. 3biallelic homozygous mutations.
4. 4chimeric mutations.

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

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

Given below are a few statements on concepts of molecular breeding.

1. A. Correlations between quantitative traits can be because of pleiotropic effects of the same gene and/or genetic linkage of genes associated with the traits.
2. B. In a Recombinant Inbred Line (RIL) population, genetic segregation of both dominant and codominant markers occurs in a 1:1 ratio.
3. C. Near isogenic lines (NILs) can be produced by repeated backcrossing of the F₁ to a recurrent parent.
4. D. SNPs are dominant markers.

Which one of the following options represents all correct statements?

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

ABA plays an important role in plant response to water stress. In the table below, column X represents some of the important enzymes in ABA biosynthesis/degradation pathways, while column Y summarizes the major function of these enzymes.

Choose the option showing the correct match between column X and column Y?

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

The following statements represent possible outcomes of competition between two species.

1. A. Niche differentiation between species
2. B. Expansion of fundamental niche of both species
3. C. Expansion of realized niche of both species
4. D. Character displacement between species

Which one of the following options represents the correct set of possible outcomes?

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

Given below are four topology diagrams corresponding to different proteins. N and C denote the N- and C-terminal ends of the protein chains.

Which one of the following statements is CORRECT?

1. 1All four are of different folds.
2. 2All four are of the same fold.
3. 3(A), (C) and (D) are of the same fold.
4. 4(A) and (C) are of the same fold.

The following statements describe different patterns of sequence evolution.

1. A. Most non-synonymous mutations are selected against.
2. B. Synonymous mutations can accumulate.
3. C. The ratio of non-synonymous to synonymous substitutions is high.
4. D. Non-synonymous sites accumulate mutations at higher rates.

Which one of the options is NOT true about sequence evolution under purifying selection?

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

Molecular phylogeny indicates that whales are closely related to the artiodactyls. Given this information, select the phylogenetic tree that shows the correct set of terrestrial animals with which modern whales share their most recent ancestry.

1. 1Tree 1
2. 2Tree 2
3. 3Tree 3
4. 4Tree 4

In a frog species, foot webbing is controlled by a single gene where the allele for nonwebbed feet (W) is dominant and webbed feet (w) is recessive. Assume there is a population of 500 individuals, where 320 have the genotype WW, 160 have the heterozygous genotype of Ww, and 20 have the genotype ww.

What are the frequencies of the three genotypes and alleles in this population?

1. 1Genotype frequencies: 0.04 WW, 0.32 Ww and 0.64 ww; Allele frequencies W – 0.5 and w – 0.5
2. 2Genotype frequencies: 0.32 WW, 0.64 Ww and 0.04 ww; Allele frequencies W – 0.8 and w – 0.2
3. 3Genotype frequencies: 0.64 WW, 0.32 Ww and 0.04 ww; Allele frequencies W – 0.8 and w – 0.2
4. 4Genotype frequencies: 0.34 WW, 0.34 Ww and 0.32 ww; Allele frequencies W – 0.5 and w – 0.5

A cancer clinic is treating four unrelated patients suffering from chronic myelogenous leukemia. A researcher sequences the Philadelphia chromosome from the leukemic cells of these patients and makes the following statements:

1. A. The DNA sequence was identical in the translocation breakage and rejoining (TBR) sections in all leukemic cells in all 4 patients.
2. B. The DNA sequence was identical in all leukemic cells from patient 1, but every patient had a different TBR sequence.
3. C. All patients have translocations between long arms of chromosomes 9 and 22.
4. D. All patients have translocations between long arm of chromosome 9 and short arm of chromosome 22.

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

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

URA3 gene expression allows yeast cells to grow on synthetic media lacking Uracil (SC-URA). Shown below are cell types having URA3 gene inserted at distinct positions of the chromosome (cell types 1, 2 and 3 from top to bottom). The ability of each cell type to grow on SC-URA in either log or stationary phase is listed in the table.

The following interpretations were made:

1. A. URA3 gene in cell type 1 is probably located in a heterochromatic region.
2. B. URA3 gene in cell type 2 is located in facultative heterochromatin.
3. C. URA3 gene in cell type 2 is probably located in a chromosome region silenced in log phase.
4. D. URA3 gene in cell type 3 is heterochromatinized in log phase.

Which one of the following options are correct interpretations?

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

A complete retroposon was cloned under the entire galactose inducible promoter. The construct, as shown below, was inserted in the yeast genome to study the transposition event.

Some of the predicted outcomes are listed below:

1. A. Cells grown in presence of glucose or galactose lead to increase in copy number of the transposon.
2. B. The transposed copies will be same as the construct inserted in the genome.
3. C. The transposed copies cannot transpose further.
4. D. The transposed copies will not respond to either glucose or galactose in the media.

Assuming that the hypothesis is correct, choose the option that has all likely outcomes.

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

Which one of the options below includes habitats that are ALL found in the Indian subcontinent?

1. 1Boreal forest, tropical rainforest, tropical deciduous forest, alluvial grassland
2. 2Temperate forest, alluvial grassland, dry thorn forest, subtropical montane forest
3. 3Scrub forest, Chapparal vegetation, dry grasslands, riparian forest
4. 4Shola grasslands, alpine grasslands, tundra, warm broadleaved forest

A researcher was interested in detecting parasite-derived antigens in Plasmodium falciparum-infected erythrocytes. The following labelling experiments were performed, followed by immunoprecipitation with antibodies against P. falciparum proteins and autoradiography.

1. A. Labeling with ³²P-ATP in the media
2. B. Labeling with ¹²⁵Iodine in the media
3. C. Labeling with ³⁵S-Methionine in the media
4. D. Labeling with ³H-Hypoxanthine in the media

Which one of the following options represents labeling experiments to predominantly detect the parasite-derived antigens?

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

The statements below are about possible genetic relatedness between individuals of a monogamous, haplodiploid insect.

1. A. A female is related to its son by 0.5
2. B. A female is related to its brother by 0.5
3. C. A male is related to its mother by 1
4. D. A male is related to its daughter by 1

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

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

Given below are some components that could potentially influence membrane fluidity.

i. Monomeric G-proteins

ii. Peripheral membrane proteins

iii. Sphingolipids

iv. Phospholipid sidechain saturation

v. Cholesterol

Choose the option that has all the components that can influence membrane fluidity.

1. 1i, ii, v
2. 2i, ii, iv
3. 3iii, iv, v
4. 4ii, iv, v

The plaque morphology of wild type and rII mutants of T4 bacteriophage following infection of different E. coli strains is summarized below.

The following two experiments were carried out:

Experiment I: Co-infection of two independent rII mutants on E. coli K strain resulted in several plaques, all being small and ragged.

Experiment II: E. coli B strain was co-infected with the above rII mutants. T4 phages from the resulting plaques were used to infect E. coli K strain. Few plaques were obtained, which were all small and ragged.

Based on the observations, the following statements were made:

1. A. Experiment I indicates that the two mutants are allelic.
2. B. Experiment II indicates that the wild type T4 phages that infected E. coli K strain resulted from a recombination event.
3. C. In experiment II, if the T4 phage isolated from the E. coli B strain was used to infect E. coli B strain, all plaques would be large and round.

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

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

One hundred IgM+ B cells were plated at 1 cell/well and activated in vitro. This led to detectable proliferation in all wells by day four. At the end of seven days, it was found that some wells contained IgG1 antibodies, some contained both IgG1 and IgA antibodies, and some contained only IgA antibodies. The following interpretations were made:

1. A. Cells that have switched to IgG1 may undergo further switching to IgA.
2. B. Cells that have switched to IgA may undergo further switching to IgG1.
3. C. A single cell can simultaneously secrete IgG1 and IgA.
4. D. The progeny of proliferating cells may undergo independent switching events.

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

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

Which of the following options represents the correct order of increasing biological organisation?

1. 1ecosystems < communities < biomes < populations
2. 2populations < communities < ecosystems < biomes
3. 3biomes < ecosystems < communities < populations
4. 4populations < ecosystems < communities < biomes

The ratio of total protein content to total RNA content was measured in yeast cells in log phase during growth in minimal media and in minimal media supplemented with amino acid cocktail. In the latter case, the ratio of protein to RNA increased dramatically. Which one of the following is a correct inference from the above information?

1. 1In minimal medium, proteins are degraded at a higher rate.
2. 2In amino acid-supplemented culture conditions, fewer ribosomes are simultaneously active on a single transcript.
3. 3In minimal medium, amino acid availability limits protein translation to a greater extent than transcription.
4. 4Amino acid supplementation reduces RNA synthesis by modification of RNA Pol II.

Given below are figures representing four different situations/examples of genetic and environmental (temperature) effects on plant height in two varieties of a plant species. In figures A, C and D, solid and dashed lines represent the mean values of plant height for the two varieties G1 and G2, respectively. In figure B, the solid and dashed lines overlap.

Given below are four statements explaining the four figures.

(i) Plant height is influenced primarily by the genotype of the two varieties.

(ii) Variation in plant height is influenced only by the temperature and genotype has no effect.

(iii) Genotype and temperature collectively have an additive effect on plant height.

(iv) Both genotype and environment have an effect on plant height with the two varieties responding differently to the environment.

Which one of the following options correctly matches the figures and their corresponding explanations?

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

A propionate kinase enzyme utilizes two substrates, propionate and acetate, with K_m for propionate being half that of acetate. Which one of the following options about the rate of the reaction at very low substrate concentrations is correct?

1. 1The rate of propionate utilization is half that of acetate.
2. 2The rate of propionate utilization is double that of acetate.
3. 3The rate of propionate utilization is equal to that of acetate.
4. 4The rate of propionate utilization is four times that of acetate.

The table below lists nomenclatural categories in column X along with their description in column Y.

Which of the following represents the correct sequence of matches:

1. 1a-iv, b-iii, c-ii, d-i
2. 2a-i, b-iv, c-iii, d-ii
3. 3a-iii, b-ii, c-i, d-iv
4. 4a-iv, b-i, c-iii, d-ii

For a population that grows exponentially in the time interval (t, t+1), we have N_t+1 = R N_t, where N denotes population size and R denotes the growth rate. Under intraspecific competition where births and deaths are density dependent, we expect the population to stabilize at carrying capacity, K. In the figure below, N_t/N_t+1 is plotted as a linear function of N_t.

We may write down the linear equation for the line joining A with B and derive a model for density-dependent population growth under intraspecific competition. Denoting (R−1)/K as a, which of the following is the correct relationship that describes population growth?

1. 1N_t+1 = N_tR / (1 + aN_t)
2. 2N_t+1 = aN_t / (1 + RN_t)
3. 3N_t+1 = N_tR / (a + N_t)
4. 4N_t+1 = aN_tR / (1 + aN_t)

The nitrogen fixing bacterium, Rhizobium leguminosarum, isolated from the root nodules of garden pea (Pisum sativum) is cultured in a petri plate containing appropriate nutrient agar medium. A bacterial colony was picked and inoculated into a liquid growth medium to scale up the culture for the production of biofertilizer. Which one of the following statements is correct?

1. 1The liquid culture will be red/pink in color due to the accumulation of the pigment leghaemoglobin.
2. 2The rhizobial cells when reinoculated into the rhizosphere of soybean plants will effectively nodulate its roots to fix atmospheric nitrogen.
3. 3The rhizobial cells cannot fix nitrogen when exposed to atmospheric air.
4. 4The rhizobial cells get transformed into bacterioids when grown in liquid media.

Following statements were made with respect to plant steroid hormones.

1. A. The receptors for plant steroid hormones are found in the nucleus, similar to animal steroid hormones.
2. B. There are multiple pathways for the plant steroid hormone biosynthesis involving cytochrome P450 class of enzymes.
3. C. The first plant steroid hormone was isolated from male gametophytes.
4. D. Plants deficient for the steroid hormone brassinosteroid show underproliferation of phloem and overproliferation of xylem cells.
5. E. Castasterone is a plant steroid hormone abundant in the vegetative tissues of the plant.

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

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

The stimulation of sympathetic cardiac nerves increases the rate of action potential generation from the sinoatrial (SA) node of heart. The following statements suggest the mechanism of this action:

1. A. The depolarizing effect of ‘h’ current (I_h) is decreased by sympathetic stimulation.
2. B. Norepinephrine secreted by the sympathetic endings binds to β₁ adrenoceptors resulting in the increase of intracellular cAMP.
3. C. The increased intracellular cAMP facilitates the opening of long-lasting (L) Ca⁺⁺ channels.
4. D. The Ca⁺⁺ current (I_Ca) due to the opening of voltage-gated L Ca⁺⁺ channels is decreased.

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

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

Four groups of students (A – D) were asked to determine whether memory B cells generated in mice immunized with ovalbumin (OVA), in Complete Freund’s adjuvant (CFA), could mount a secondary antibody response (recall response) to OVA in vitro. The groups did the following experiments:

Group A students harvested serum from the mice, loaded it on OVA-coated ELISA plates and showed that IgG and IgA anti-OVA antibodies were present.

Group B students harvested long-lived plasma cells from bone marrow of the mice, plated them in culture for 5 days and showed anti-OVA antibodies in supernatant by ELISA.

Group C students infected an epithelial cell line with the virus and showed that spleen cells from the mice could kill the infected targets.

Group D students stimulated spleen cells from the mouse with OVA for 5 days and showed anti-OVA antibodies in supernatant by ELISA.

Which one of the following options represents group(s) that did the correct experiment?

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

The following statements are made about the variety of thermoregulatory mechanisms in the body.

1. A. Human voluntary activity is decreased in cold.
2. B. There is a cutaneous vasodilation by heat.
3. C. There is an increased secretion of epinephrine and nor-epinephrine in cold.
4. D. There is a decreased heat production in cold.

Choose the combination of all correct statements about thermoregulatory mechanisms.

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

A KDEL sequence is added at the C-terminus of a secreted glycoprotein X (500 amino acid residues) having no site for N-linked glycosylation and expressed from an inducible promoter. Following 10, 20 and 60 minutes of induction, ER are purified and probed for newly synthesized glycoprotein X-KDEL. The immunoblot obtained is shown below.

Which one of the following statements is the most likely explanation for presence of the higher molecular weight bands in lanes 20 and 60 minutes?

1. 1The signal sequence is not removed from some of the glycoprotein X-KDEL molecules.
2. 2Glycoprotein X-KDEL becomes modified in the endoplasmic reticulum after protein synthesis is completed.
3. 3The glycoprotein X-KDEL molecules are modified in the Golgi prior to ER retrieval.
4. 4The quality control mechanism in the ER recognizes a pool of glycoprotein X-KDEL as being aberrant and targets it for degradation.

The inhibitory IκBα protein binds to the NFκB dimer and holds them in an inactive state. On TNF treatment, the IκBα protein is degraded and NFκB enters the nucleus to transactivate gene expression. Importantly, one of the transcriptional targets of NFκB is the IκBα gene itself. Together, they form a negative feedback loop. Which one of the following graphs represents the NFκB protein expression kinetics when TNF exposure is given as a pulse (a) or continuously (b)?

1. 1Graph set 1
2. 2Graph set 2
3. 3Graph set 3
4. 4Graph set 4

The mouse homozygous null mutant for a gene bfg always dies mid-gestation. Chimeric mice made of bfg null cells and wild-type cells have healthy pups. When the developing brain of these pups is examined, they have more than two hippocampi. Closer examination reveals bfg null cells at the centre of these supernumerary hippocampi.

Which of the following inferences can correctly be drawn from this experiment?

1. 1Wild type bfg function in the developing brain induces hippocampus specification in neighbouring cells.
2. 2Wild type bfg function in the developing brain suppresses hippocampus specification in neighbouring cells.
3. 3bfg function is completely cell autonomous.
4. 4bfg function is hippocampus specific.

The given table shows the annual Net Primary Productivity (NPP), season length, and Leaf Area Index (LAI) for various ecosystems.

Which one of the following options represents the correct order of decreasing NPP per day per unit leaf area?

1. 1Desert > Tundra > Tropical Forest > Temperate Forest
2. 2Tropical Forest > Temperate Forest > Tundra > Desert
3. 3Tundra > Desert > Temperate Forest > Tropical Forest
4. 4Temperate Forest > Tropical Forest > Desert > Tundra

Here is some data for a cohort of 400 individuals of a species whose abundance was tracked for 6 years (its maximum lifespan). For one-year age intervals from birth to 6 years, you have the following numbers of survivors, 400, 200, 100, 40, 20, 10, and 0. The corresponding per capita birth rates are 0.1, 2.0, 3.0, 4.0, 4.0, 3.0, and 0.0. What is the basic reproductive rate R₀?

1. 12.52
2. 22.92
3. 32.36
4. 43.20

The types of mammalian nerve fibers (Column X) and the conduction velocity in m/s of nerve impulses (column Y) are listed below:

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

1. 1a-i, b-ii, c-iii, d-iv
2. 2a-ii, b-iii, c-iv, d-i
3. 3a-iii, b-iv, c-i, d-ii
4. 4a-iv, b-i, c-ii, d-iii

Given below are statements on concepts of genetics.

1. A. The degree to which a particular gene is expressed in a phenotype is called ________.
2. B. A heritable change in gene expression that does not result from a change in the nucleotide sequence of the genome is called ________ change.
3. C. The frequency with which a dominant or homozygous recessive gene is phenotypically expressed within a population is called ________.
4. D. An allele that results in the death of organisms that is homozygous for the allele is ________.

Which one of the following options represents the most appropriate sequence of terms to fill all the blank spaces in the above statements?

1. 1A – expressivity, B – epigenetic, C – penetrance, D – recessive lethal
2. 2A – penetrance, B – mutation, C – expressivity, D – dominant lethal
3. 3A – penetrance, B – epigenetic, C – distribution, D – conditional lethal
4. 4A – epistasis, B – mutation, C – penetrance, D – dominant lethal

The table below represents a list of animals and larval stages.

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

1. 1a-ii, b-i, c-iii
2. 2a-i, b-iii, c-ii
3. 3a-ii, b-iii, c-i
4. 4a-iii, b-ii, c-i

The theoretical resolution limit of the fluorescence microscope is about 200 nm. Super-resolution microscopy has been developed to address this limitation. Given below are super-resolution microscopy methods in column X and their principle in column Y.

Which one of the following options represents the correct match between column X and column Y?

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

RPMI and DMEM, supplemented with serum, antibiotics, glutamine and phenol red are routinely used for tissue culture of human cells in CO₂ incubators. In addition, sodium bicarbonate (NaHCO₃) and HEPES are used as buffering agents. The following statements were made about the media.

1. A. While 5% CO₂ is optimal for cells cultured in RPMI, the optimal CO₂ concentration for DMEM is 7.5-10%.
2. B. HEPES is necessary if cells are to be kept outside the incubator in room air for long periods.
3. C. NaHCO₃ is necessary if cells are to be kept outside the incubator in room air for long periods.
4. D. When cells grow rapidly in the culture medium for a few days, phenol red will turn the medium pink/red.

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

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

In a protein stability study, three solutions, MolA (10 kDa) at 0.5 mM, MolB (20 kDa) at 0.5 mM, and MolC (20 kDa) at 1 mM, were subjected to denaturation by urea, SDS and guanidium hydrochloride (GnHCl), respectively. The profiles of the fraction of unfolded protein with increasing concentration of the denaturants is given below.

Which one of the following corresponds to reaction conditions at which the number of molecules of folded protein are equal, assuming the reaction volumes to be the same for all experiments?

1. 10.2 M urea; 0.05 % SDS; 4.5 M GnHCl
2. 22 M urea; 0.05 % SDS; 1 M GnHCl
3. 30.2 M urea; 0.25% SDS; 4.5 M GnHCl
4. 42 M urea; 0.25 % SDS; 1 M GnHCl

DNA polymerase PolA has high fidelity but low processivity and DNA polymerase PolB has low fidelity and high processivity. In vitro reactions for DNA synthesis using limiting amount of PolA or PolB were set to further characterise the enzymes according to the following scheme:

Which of the following outcome do you expect?

1. 1Tube 1 will have more T3 DNA and tube 2 will have more T7 DNA.
2. 2Tube 1 will have more T7 DNA and tube 2 will have more T3 DNA.
3. 3Both tubes will have more T3 DNA than T7 DNA.
4. 4Both tubes will have more T7 DNA than T3 DNA.

Given below are protein domains and their binding specificities.

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

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

A plant breeder plans to introgress a gene for pathogen resistance (R) from a wild species (B) into a cultivated variety (A). Panel I in the figure shows a profile of DNA markers for A and B. Panel II shows a genetic map for the linkage group which has the gene for pathogen resistance.

Which one of the following options has the correct choice of markers for foreground (FG) and background (BG) selection, respectively?

1. 1FG: B3, A4 and BG: A2, A3, A7
2. 2FG: B3, B2 and BG: A1, A5, A6, A8
3. 3FG: B3, B2 and BG: A2, A3, A4, A7
4. 4FG: B3, A4 and BG: A2, B2, B7 and A7

The following gel patterns are that of DNA markers observed in parents (P1 and P2), F₁ from a cross between them and doubled haploid progeny (panel A) or F₂ progeny, derived from selfing of F₁ (panels B and C).

A doubled haploid (DH) is a genotype formed when plants are developed from haploid cells which have undergone chromosome doubling.

Based on the pattern observed in the DH or F₂ progeny identify which of the patterns (A to C) are based on DNA markers that are allelic?

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

Recessive mutations in the human dysferlin gene lead to Limb Girdle type II muscular dystrophy. The gene is located on the second chromosome. The patient’s parents do not have Limb Girdle type II dystrophy B. What is the probability that at least one of the four grandparents of this patient suffered from this disease?

1. 11/4
2. 23/10
3. 31/2
4. 47/10

For the coupled reaction given below, the equilibrium constants (K′_eq) for equation [1] and equation [2] are 270 and 890, respectively.

Glucose 6-phosphate + H₂O → glucose + P_i [1]

ATP + glucose → ADP + glucose 6-phosphate [2]

The standard free energy of hydrolysis of ATP at 25°C is

1. 1−(24 to 26) kJ/mol
2. 2−(18 to 20) kJ/mol
3. 3−(30 to 32) kJ/mol
4. 4−(60 to 62) kJ/mol

Following statements are made regarding the nature of the chromosomes in bacteria.

1. A. Most bacterial chromosomes are circular. However, in few bacteria, linear chromosomes exist.
2. B. All the bacterial systems are known to have a single chromosome.
3. C. Some bacterial chromosomes contain enhancer-like elements.
4. D. Chromosomes in bacteria are stabilized by histone-like proteins

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

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

Select the option that correctly identifies the three labelled floral parts in the floral diagram of a grass flower:

1. 1A- palea, B- lemma, C- lodicule
2. 2A- lemma, B- lodicule, C- stamen
3. 3A- palea, B- stamen, C- lemma
4. 4A- lodicule, B- palea, C- lemma

The names of the plant pathogens and their taxonomic groups are given in the table.

Choose the option with all the correct matches:

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