IIT JAM Biotechnology 2025 Question Paper with Answer Key

The porphyrin ring (tetrapyrrole structure) is NOT found in functional

1. Achlorophyll
2. Bhemoglobin
3. Chemocyanin
4. Dleghemoglobin

If P is the matrix below and P + P^T = I, the value of α (0 ≤ α ≤ π/2) is

1. Aπ/2
2. Bπ/3
3. C3π/2
4. D0

After how many cycles of polymerase chain reaction (PCR), the amplified product of required length is generated for the first time from a chromosomal DNA template?

1. A2
2. B3
3. C4
4. D5

In humans, Down syndrome is caused by

1. ATrisomy 16
2. BTrisomy 18
3. CTrisomy 21
4. DTrisomy 22

Which one of the following hormones is produced by the adrenal gland?

1. AThyroxine
2. BCortisol
3. CInsulin
4. DMelatonin

What is the ploidy level of a sporophyte in angiosperms?

1. An
2. B2n
3. C3n
4. D4n

The standard free energy change (ΔG°) of the binding reaction between different sweet molecules and a common sweet taste receptor are given. Which amongst these molecules is the sweetest at the same molar concentration?

1. ASucrose (−6.7 kcal mol⁻¹)
2. BSaccharin (−9.7 kcal mol⁻¹)
3. CAlitame (−11.1 kcal mol⁻¹)
4. DNeotame (−12.1 kcal mol⁻¹)

The correct order of electronegativity of the given elements is

1. AB > C > N > O > F
2. BF > O > N > C > B
3. CF > N > O > C > B
4. DO > F > N > C > B

Which of the following terrestrial biomes has the highest animal diversity?

1. ATropical forest
2. BSavana
3. CChaparral
4. DTundra

An electric circuit with a resistor of constant resistance ‘R’ is maintained at a constant voltage ‘V’. Based on Ohm’s law, if the current ‘I’ through the circuit is doubled, the power ‘P’ dissipated across the resistor is

1. AP/2
2. BP
3. C2P
4. D4P

Sequence comparison of which of the following genes is used as a measure of evolutionary divergence across bacterial species?

1. ApbpG
2. BslyD
3. C16S rRNA
4. D18S rRNA

Which of the following activities is NOT possessed by the human immunodeficiency virus-1 reverse transcriptase?

1. ASynthesis of DNA from RNA
2. BSynthesis of DNA from DNA
3. CDegradation of RNA strand of RNA: DNA hybrid
4. DSynthesis of mRNA from DNA

Bacterial cloning vectors and bacterial expression vectors are differentiated by the presence of

1. Aantibiotic resistance gene cassette
2. Borigin of replication
3. Cpromoter and ribosome-binding site
4. Dunique restriction sites

The final stage of peptidoglycan (PG) biosynthesis is marked by PG cross-link formation and remodeling. Which of the following enzymes does NOT take part in these processes?

1. ATransglycosidases
2. BTranspeptidases
3. CTransaminases
4. DDD-carboxypeptidases

The first evidence of ‘gene transfer’ was demonstrated in 1928 by

1. AJoshua Lederberg in Escherichia coli
2. BFrederick Griffith in Streptococcus pneumoniae
3. CJoshua Lederberg in bacteriophages
4. DAlexander Fleming in Penicillium notetum

Which of the following statements about eukaryotic asymmetric cell division is NOT correct?

1. AChromosomes are unequally distributed in the daughter cells
2. BChromosomes are equally distributed in the daughter cells
3. CRNA and proteins are unequally distributed in the daughter cells
4. DCytoplasmic contents are unequally distributed in the daughter cells

Which of the following represents the CORRECT order of events in the eukaryotic cell cycle?

1. AG1 → S → G2 → M
2. BS → G1 → M → G2
3. CG1 → S → M → G2
4. DS → G1 → G2 → M

The receptors for gamma amino butyric acid (GABA) in humans are

1. Aligand gated chloride ion channels
2. Bligand gated sodium ion channels
3. Cligand gated potassium ion channels
4. Dligand gated calcium ion channels

Which of the following cell types is infected by the human immunodeficiency virus-1?

1. AT-helper lymphocytes
2. BT-cytotoxic lymphocytes
3. CPlasma cells
4. DB-lymphocytes

The IR stretching frequency of the carbonyl (C=O) group of a typical saturated ketone is 1715 cm⁻¹. The IR stretching frequencies for the carbonyl groups present in three different acetophenone (methyl phenyl ketone) derivatives are given. Match the molecules in Group I with their corresponding frequencies in Group II

1. AP-1, Q-2, R-3
2. BP-2, Q-3, R-1
3. CP-3, Q-1, R-2
4. DP-3, Q-2, R-1

Two charges 10 × 10⁻⁸ C and −6 × 10⁻⁸ C are located 16 cm apart. The point(s) on the line joining the two charges, where the net electric potential is zero, will be

[Take the potential at infinity to be zero]

1. A10 cm and 40 cm away from the positive charge on the side of the negative charge
2. B10 cm and 40 cm away from the negative charge on the side of the positive charge
3. C10 cm away from the negative charge on the side of the positive charge
4. D40 cm away from the negative charge on the side of the positive charge

Match the pair of orgamisms in Group I with their community interaction pattern in Group II.

1. AP-3, Q-1, R-4, S-2
2. BP-3, Q-4, R-1, S-2
3. CP-4, Q-1, R-3, S-2
4. DP-2, Q-3, R-1, S-4

Match the animals in Group I with the major form of excreted nitrogen metabolite in Group II

1. AP – 3, Q – 1, R – 2
2. BP – 1, Q – 2, R – 3
3. CP – 2, Q – 3, R – 1
4. DP – 3, Q – 2, R – 1

Identify the taxa that constitute a paraphyletic group in the given phylogenetic tree?

1. AA, B, C
2. BD, E, F
3. CB, C, D
4. DC, D, E

Which of the following is the CORRECT combination of a synthetic auxin and a synthetic cytokinin?

1. A2,4-Dichlorophenoxy acetic acid (2,4-D) and Indole-3-acetic acid (IAA)
2. B2,4-Dichlorophenoxy acetic acid (2,4-D) and 6-Benzylamino purine (BAP)
3. C6-Benzylamino purine (BAP) and Zeatin
4. DIndole-3-acetic acid (IAA) and Zeatin

Mechanism of antibacterial action of polymyxins relies on the

1. Ainhibition of 30S ribosomal subunit
2. Bdisruption of peptidoglycan synthesis
3. Cinhibition of DNA replication of bacteria
4. Ddisruption of membrane architecture of bacteria

The 5′ cap of eukaryotic mRNAs contains

1. Aa modified guanine nucleotide
2. Ba modified adenine nucleotide
3. Ca modified cytosine nucleotide
4. Da modified uracil nucleotide

Which one of the following statements is CORRECT about Agrobacterium tumefaciens-mediated plant transformation?

1. AThe marker gene for the selection of plant transformant is located outside the T-DNA segment of the transformation plasmid
2. BThe marker gene for the selection of bacterial transformant is located within the T-DNA segment of the transformation plasmid
3. CTwo T-DNA border sequences (left and right) are essential to design a binary vector system
4. DIn binary vector system, the vir genes and two T-DNA border sequences (left and right) are present in the same transformation plasmid

Which of the following conditions is CORRECT for free expansion of an ideal gas under adiabatic condition? (q = heat, ΔT = temperature difference, w = work)

1. Aq = 0, ΔT < 0, w ≠ 0
2. Bq = 0, ΔT ≠ 0, w = 0
3. Cq ≠ 0, ΔT = 0, w = 0
4. Dq = 0, ΔT = 0, w = 0

Four alkyl halides, MeBr, EtBr, i-PrBr and t-BuBr, undergo S_N2 reactions in the presence of hydroxide ion to yield the corresponding alcohols and the halide ion. The CORRECT order of the alkyl halides based on the rates of reactions is

1. AMeBr > EtBr > i-PrBr > t-BuBr
2. Bt-BuBr > i-PrBr > EtBr > MeBr
3. Ci-PrBr > t-BuBr > EtBr > MeBr
4. DEtBr > i-PrBr > t-BuBr > MeBr

Which of the following statement(s) is/are CORRECT about Deinococcus radiodurans?

1. AIt has a cell wall consisting of several layers, including an outer membrane that lacks lipid A
2. BPeptidoglycan in its cell wall has ornithine, in place of diaminopimelic acid, in the N-acetyl muramic acid cross-bridges
3. CIt is a Gram-negative organism
4. DIt can survive an exposure up to 15000 Gy of ionizing radiation

Which of the following statement(s) is/are CORRECT about ‘stringent response’ in bacteria?

1. AIt is linked to reduced growth rate
2. BGuanosine tetraphosphate (ppGpp) alone is sufficient to trigger the process
3. CBoth guanosine tetraphosphate (ppGpp) and guanosine pentaphosphate (pppGpp) are required to trigger the process
4. DRelA and/or SpoT are/is involved in triggering the process

The method(s) used to detect a DNA fragment of 150 base pairs is/are

1. Aagarose gel electrophoresis
2. Bnorthern blotting
3. Cpolyacrylamide gel electrophoresis
4. Dwestern blotting

The component(s) of the apoptosome is/are

1. Acytochrome c
2. Bprocaspase 9
3. Ccaspase 3
4. Dcaspase 8

Which of the following statement(s) is/are CORRECT for lac repressor expressed from the lacI gene?

1. AThe lac repressor is allosterically controlled and it binds to lac operator
2. BThe gene lacI is in the ‘cis’ configuration with respect to lac operon
3. CThe presence of glucose weakens the binding of lac repressor to lac operator
4. DThe lac repressor regulates ‘in trans’ the expression of a gene cloned under the control of lac promoter

Which of the following condition(s) lead(s) to reduced affinity of O₂ for human hemoglobin?

1. AReduction of pH of blood plasma from pH 7.4 to 7.2
2. BDecrease of partial pressure of CO₂ in the lungs from 6 to 2 kPa
3. CEnhancement of intracellular 2, 3-bis phosphoglycerate (BPG) level from 5 to 8 mM
4. DIncrease in ambient CO level from 1 to 600 ppm

Which of the following metabolite(s) accumulate(s) in the blood of a human adult consuming a ketogenic diet?

1. AD-β-hydroxybutyrate
2. BAcetoacetate
3. CPyruvate
4. DOxaloacetate

In ‘Futile Cycle’ chemical energy is dissipated as heat due to two opposite biochemical reactions. Which of the following biochemical reaction(s) is/are a part of ‘Futile Cycle’?

1. AGlucose ↔ Glucose-6-phosphate
2. BFructose-6-phosphate ↔ Fructose-1,6-bisphosphate
3. CGlucose-6-phosphate ↔ Fructose-6-phosphate
4. D1,3-bisphosphoglycerate ↔ 3-phosphoglycerate

Which of the following statement(s) is/are CORRECT in the classical ‘ABC model’ for genetic control of flower development?

1. A‘Class A’ genes solely determine sepal identity
2. B‘Class B’ genes solely determine petal identity
3. C‘Class C’ genes solely determine stamen identity
4. D‘Class C’ genes solely determine carpel identity

Which of the following is/are CORRECT for the two molecules shown?

1. AThey are stereoisomers
2. BEach of them has two stereogenic centers
3. CThey are mirror images of each other
4. DThey are diastereoisomers

Free energy change for transport of an uncharged solute across a membrane against a 1 × 10³ fold concentration gradient at 25 °C is _____________ kJ mol⁻¹. (rounded off to 2 decimals)

[R = 8.315 J mol⁻¹ K⁻¹]

Type a number as your answer.

A forest has four different tree species (A, B, C and D) and their numbers are: A = 60; B = 20; C = 10 and D = 10.

The Shannon biodiversity index of the trees in this forest is ________________. (rounded off to 2 decimals)

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In a plant species, the genotype DDEE is crossed with the genotype ddee; and the F₁ is test crossed. Considering that the two genes are linked and 20 map unit (cM) apart in the chromosome, the percentage (%) of the test cross progeny with the genotype ddee is _______________. (answer in integer)

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In a farm animal breeding programme, the animal with the dominant A phenotype, the recessive b phenotype, the dominant D phenotype, and the recessive e phenotype are commercially important. The inheritance of these traits follows Mendelian laws. From the tetra-hybrid cross of two genotypes AaBbDdEe and AaBbDdEe, the expected frequency of offspring that will show all the above-mentioned desired phenotypes is __________________. (rounded off to 3 decimals)

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The wavelength of a photon emitted during a transition from n = 3 to n = 2 state in the H atom is _____________ nm. (answer in integer)

[Rydberg energy constant R_H = 2.18 × 10⁻¹⁸ J; Planck constant h = 6.626 × 10⁻³⁴ J s, c = 3 × 10⁸ m s⁻¹]

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The limit of the function lim_x→2 ((2x² + 2x − 12) / (x² − 4)) is _____________. (rounded off to 1 decimal)

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A candle is placed 18 cm in front of a concave mirror to generate a real, inverted and doubly magnified image. The radius of curvature of the concave mirror is ____________ cm. (answer in integer)

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E⁰ value of a Daniell cell Zn|Zn²⁺(aq)||Cu²⁺(aq)|Cu is ___________ V. (rounded off to 2 decimals)

[E⁰_Zn²⁺|Zn = −0.76 V; E⁰_Cu²⁺|Cu = +0.34 V]

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A population of bacterial cells grows from 10,000 to 100,000,000 cells in 6 hours. The generation time of the bacterial population is __________ min. (rounded off to 2 decimals)

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In a sampling expedition near a peninsula, 180 dolphins from a large population of dolphins were captured and marked by tagging their dorsal fins. The tagged dolphins were then allowed to join back into the population. In a subsequent expedition, 42 dolphins were photographed from same large population. Among these, 7 dolphins contained the tags. Assuming that the population size remains the same and that tags were not lost, the estimated population size of dolphins in the peninsula is _____________. (answer in integer)

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The area bounded by the curve y = sin x and the x axis between x = 0 and x = 3π/2 is ___________ sq. units. (answer in integer)

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The number of 7 letter words (with or without meaning) starting with the letter B that can be formed using the letters of the word BIOLOGY is ________________. (answer in integer)

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Three particles A, B, C with masses of 100 g, 200 g, and 300 g, respectively, are placed at the vertices of an equilateral triangular structure with a side length of 2 m. A is placed at the (0, 0) position and B is placed at (2, 0) position in a Cartesian coordinate system. Assume that ΔABC lies parallel to the base. The distance between the center of mass and position of the particle A is ______________ m. (rounded off to 2 decimals)

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An insect weighing 5 g takes off vertically for a distance of 100 cm with a speed of 4 m s⁻¹ by using its hind legs. Ignoring the resistance due to air, the magnitude of the average net force exerted by the hind legs during the take-off is _____________ N. (rounded off to 3 decimals)

[g = 9.8 m s⁻²]

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A buffer solution is composed of 0.1 M acetic acid and 0.15 M sodium acetate. The change in pH of 1 L buffer solution upon addition of 50 mL of 1.0 M NaOH is ______________. (rounded off to 2 decimals)

[K_a of acetic acid = 1.75 × 10⁻⁵]

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In a reaction A + B → C, the initial rate of formation of C at 25 °C was measured for different initial concentrations of A and B as given. The overall order of the reaction with respect to both A and B is ________. (answer in integer)

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A cDNA was synthesized from the mRNA of a eukaryotic gene. After cloning and sequence analysis, the double-stranded cDNA of 614 bp revealed 125 bp 5′-UTR and 120 bp 3′-UTR. The number of amino acids present in the polypeptide encoded by this gene is _____________. (answer in integer)

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A rare genetic disorder resulting from homozygosity for a recessive allele (r) occurs in 2 out of every 10,000 individuals in a population. Assuming that (i) the disorder is not lethal, (ii) the disorder does not impact reproductive success, (iii) no new mutations are introduced in the population, and (iv) the population follows Hardy-Weinberg equilibrium, the percentage (%) of the carriers in the population that pass the r allele to offspring is _________. (rounded off to 1 decimal)

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The vector, shown in the figure, has promoter and RBS sequences in the 300 bp region between the restriction sites for enzymes X and Y. There are no other sites for X and Y in the vector. The promoter is directed towards the Y site. The insert containing only an ORF provides 3 fragments after digestion with both enzymes X and Y. The ORF is cloned in the correct orientation in the vector using the single restriction enzyme Y. The size of the largest fragment of the recombinant plasmid expressing the ORF upon digestion with enzyme X is ___________ bp. (answer in integer)

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The length of the edge of a variable cube is increasing at the rate of 25 cm s⁻¹. If the initial length of the edge of the cube is 10 cm, the rate of increase of the surface area of the cube is _________ cm² s⁻¹. (answer in integer)

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