GATE XL 2026 Question Paper with Answer Key

Suresh said, “I did it yesterday.” Which one of the following options is the correct form of this sentence in indirect speech?

1. ASuresh said that I did it yesterday.
2. BSuresh says I did it yesterday.
3. CSuresh says that he did it the day before.
4. DSuresh said that he had done it the day before.

To continue the sequence of tiles shown, the tile indicated by the question mark should be

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

Consider an art gallery whose walkways are shown as lines in the diagram. A black dot represents a junction of two walkways. A guard may be placed at a junction to watch over the walkways that join at that junction. The minimum number of guards needed to watch all the walkways is ________.

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

The 2^nd of June is a Thursday in a certain year. Which day of the week is the 3^rd of July in that year?

1. AThursday
2. BFriday
3. CSaturday
4. DSunday

A coin with heads facing up is shown as (H) and a coin with tails facing up is shown as (T).

Six coins are placed in the Starting Arrangement, as shown in the figure below. A “step” is defined as interchanging a pair of adjacent coins without flipping them. The minimum number of steps needed to go from the Starting Arrangement to the Final Arrangement, as shown in the figure, is ________.

1. A3
2. B6
3. C9
4. D12

Exacerbate : Mitigate :: ___________ Choose the option with the correct pair of words to fill the blank.

1. AAggravate : Alleviate
2. BAlleviate : Precipitate
3. CAggravate : Precipitate
4. DEmancipate : Exonerate

A paper shown in Panel I is folded along the dashed lines (- – -) to construct a cube. The shaded regions shown in Panel I appear on the outer surface of the cube. Referring to cubes shown in Panel II, which one of the options is correct?

1. AOnly (i) can correspond to the unfolded cube in Panel I.
2. BOnly (ii) can correspond to the unfolded cube in Panel I.
3. CBoth (i) and (ii) can correspond to the unfolded cube in Panel I.
4. DNeither (i) nor (ii) can correspond to the unfolded cube in Panel I.

In a population, patients who have high cholesterol also have high blood-pressure (BP). Some patients with high BP also have diabetes. There are no patients who have both high cholesterol and diabetes. Furthermore,

1. the total number of patients with at least one of these conditions is 75,
2. the number of patients with high cholesterol is 10,
3. the number of patients with high BP is 45, and
4. the number of patients with only high BP and no other conditions is 20.

Then the number of patients who have both diabetes and high BP is _______

1. A0
2. B15
3. C20
4. D10

Four people P, Q, R, and S, of different ages, make the following observations.

P – I am younger than S.
Q – I am neither the youngest nor the oldest.
R – P is older than me.

Based on these observations, the youngest person is ______.

1. AP
2. BQ
3. CR
4. DS

Circles C₁, C₂, and C₃, with centers O₁, O₂, and O₃, and radii r₁, r₂, and r₃, respectively, touch each other as shown in the following figure. Given r₁ = 2 cm, r₂ = 1 cm and the angle ∠O₁O₃O₂ is 90°, r₃ = _____ cm.

1. A½(−3 + √17)
2. B½(3 + √17)
3. C½(−2 + √17)
4. D½(−3 + 2√17)

10 mM aqueous HCl is added dropwise to 10 mL of 1 mM aqueous NaOH. The qualitative plot of conductivity (y) against the number of drops of HCl (x) is

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

Upon hydrolysis of the pentapeptide Glu-Arg-Gly-Phe-Ala (represented from N- to C- terminus) with trypsin, the peptide fragments obtained are

1. AGlu-Arg and Gly-Phe-Ala
2. BGlu-Arg-Gly-Phe and Ala
3. CGlu and Arg-Gly-Phe-Ala
4. DGlu-Arg-Gly and Phe-Ala

The major product formed in the following reaction is

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

The CORRECT order of ionic character (in percentage) among the following is

1. ANaCl < HCl < HBr
2. BHCl < NaCl < HBr
3. CHCl < HBr < NaCl
4. DHBr < HCl < NaCl

The CORRECT combination(s) of element and their ground state electronic configuration is/are

(Atomic Numbers: Ar-18, Sc-21, Cr-24, Mn-25 and Fe-26)

1. ASc – [Ar] 4s² 3d¹
2. BCr – [Ar] 4s² 3d⁴
3. CMn – [Ar] 4s² 3d⁵
4. DFe – [Ar] 4s² 3d⁶

The major component(s) of phosphate buffer at physiological pH of 7.4 is/are

1. AH₃PO₄
2. BH₂PO₄⁻
3. CHPO₄²⁻
4. DPO₄³⁻

The total number of distinct stereoisomers for the following compound is _______________ (in integer).

Type a number as your answer.

For the reaction A → products, the half-life is independent of the initial concentration of A. The order of the reaction is ________________ (in integer).

Type a number as your answer.

Among the following, the number of molecules possessing one or more lone pairs on the central atom is ________________ (in integer). BeCl₂ SnCl₂ BF₃ NH₃ SF₄ PF₅ and SF₆

Type a number as your answer.

An ideal gas in an insulated container expands against zero external pressure. For this expansion, the CORRECT statement is

1. AWork is done by the gas
2. BWork is done on the gas
3. CPressure of the gas remains unchanged
4. DTemperature of the gas remains unchanged

The major products P and Q obtained in the following reactions are

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

The major product formed in the following two-step transformation is (Note: Ts = tosyl and Ac = acetyl)

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

Match the coordination complexes given in Column I with their most appropriate properties in Column II.

(Given: Atomic number of Mn-25; Co-27; Cu-29):

1. AE-IV, F-III, G-II, H-I
2. BE-II, F-IV, G-I, H-III
3. CE-IV, F-I, G-II, H-III
4. DE-I, F-III, G-IV, H-II

The CORRECT statement(s) about a competitive inhibitor of an enzyme is/are

1. AThe competitive inhibitor binds to the substrate-binding site of the enzyme
2. BThe competitive inhibitor binds to the substrate
3. CThe competitive inhibitor is less effective at higher substrate concentration
4. DThe competitive inhibitor is more effective at higher substrate concentration

Among the following, the occupied molecular orbital(s) of carbon monoxide is/are

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

The option(s) with the CORRECT order of ionisation energy is/are

1. AAl⁺ < Al²⁺ < Al³⁺ < Al⁴⁺
2. BAl⁴⁺ < Al³⁺ < Al²⁺ < Al⁺
3. CCl⁻ < Cl < Cl⁺
4. DCl⁺ < Cl < Cl⁻

The pH of 10⁻⁸ M HCl (aq.) is ____________ (rounded off to two decimal places). Given, pK_w = 14.

Type a number as your answer.

Which one of the following immunoglobulins is known for its role in both allergy and asthma?

1. AIgA
2. BIgM
3. CIgD
4. DIgE

In which kind of organism, the glycerol moiety of lipid is found primarily in the R-configuration?

1. ABacteria
2. BMammals
3. CArchaea
4. DYeast

The Kennedy pathway of cellular phospholipid biosynthesis is associated with ______ .

1. Aperoxisome
2. Bmitochondria
3. Cnucleus
4. Dendoplasmic reticulum

Which of the following options show(s) the correct pairing of a complement protein with its function?

1. AC5a : inflammation
2. BC3b : opsonization
3. CC3a : opsonization
4. DC5b : inflammation

Fluorescence is a result of which one or more of the following?

1. AThe transition of electrons from singlet ground state to singlet transition state.
2. BThe transition of electrons from lower singlet excited state to singlet ground state.
3. CThe release of energy in the form of light of wavelength higher than the incident wavelength.
4. DThe release of energy in the form of light of lower wavelength than the incident wavelength.

A 25 amino acid α-helical protein is spanning the thickness of a mammalian cell membrane. Using the average dimensional parameters of a typical α-helix, the thickness of the membrane will be ______ Å (rounded off to one decimal place).

Type a number as your answer.

The oxidative phase of the hexose monophosphate pathway generates __________ moles of NADPH per mole of glucose 6-phosphate (answer in integer).

Type a number as your answer.

Partial double digestion of the DNA shown below with EcoRI, and XhoI will yield ______ bands after gel electrophoresis (answer in integer).

Type a number as your answer.

Chymotrypsin cleaves polypeptides preferentially on the carbonyl side of aromatic, and some other bulky nonpolar residues. Trypsin cleaves on the carbonyl side of positively charged residues. Digestion of a polypeptide having the composition- Ala₂, Gly, Lys₂, Phe, Thr, Trp, Val, independently by these two proteases yielded peptide fragments as shown in the figure below.

Which one of the following is the correct primary structure of the polypeptide?

1. AAla-Ala-Trp-Gly-Lys-Lys-Thr-Phe-Val
2. BThr-Phe-Val-Lys-Ala-Ala-Trp-Gly-Lys
3. CVal-Lys-Ala-Ala-Trp- Gly-Lys-Thr-Phe
4. DThr-Phe-Ala-Ala-Trp-Val-Lys-Gly-Lys

Which one of the following enzymes is NOT inhibited by glucose-6-phosphate?

1. AHexokinase I
2. BHexokinase II
3. CHexokinase III
4. DHexokinase IV

The following diagram represents energy states of different protein folding steps, which includes- 1. Folded 2. Transition 3. Molten globule 4. Unfolded

Find the correct match of folding steps (1 to 4) with the energy state (P to S) in the diagram.

1. A1-S, 2-R, 3-Q, 4-P
2. B1-S, 2-R, 3-P, 4-Q
3. C1-R, 2-Q, 3-S, 4-P
4. D1-P, 2-Q, 3-R, 4-S

The correct path of transfer of electrons in the light harvesting photosystems in vascular plants is _____________.

1. AH₂O → Photosystem II → Cyt b₆f → Photosystem I → NADP⁺
2. BH₂O → Photosystem I → Cyt b₆f → Photosystem II → O₂
3. CH₂O → Photosystem II → Cyt b₆f → Photosystem I → O₂
4. DH₂O → Photosystem I → Cyt b₆f → Photosystem II → NADP⁺

For a simple enzyme that follows Michaelis-Menten kinetics, kinetic data was collected in the absence (dotted line, -I), or presence (solid line, +I) of an uncompetitive inhibitor (I). Which one of the following Eadie-Hofstee plots best describes the expected result?

(v_o = initial velocity, [S] = free substrate concentration)

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

Which statement(s) is/are true about the 5′-capping of eukaryotic mRNA?

1. ATriphosphatase enzyme removes the γ-phosphate from the 5′-terminal nucleotide.
2. BA transferase links ATP to the dephosphorylated nucleotide of mRNA at its 5′-end.
3. CMethyl transferase adds a –CH₃ group to the N-7 position of the newly added guanine base.
4. D5′-capping happens shortly after mRNA emerges from the exit tunnel of RNA polymerase.

Which of the following statements about pertussis toxin is/are NOT true?

1. AIt causes whooping cough.
2. BIt is a heterodimeric protein.
3. CIt causes ADP-ribosylation of the α-subunit of G_i.
4. DIt inhibits adenylate cyclase.

Telomerase has which one or more of the following activities?

1. ADNA-dependent RNA polymerase
2. BReverse transcriptase
3. CRNA-dependent DNA polymerase
4. D5′→3′ exoribonuclease

To a 10 × 10⁻⁹ M solution of a receptor, its specific ligand was added, and incubated. At equilibrium, the concentration of the free ligand was 5 × 10⁻⁹ M, and the concentration of the receptor-ligand complex was 6 × 10⁻⁹ M. The dissociation constant for the receptor-ligand interaction is _________ × 10⁻⁹ M (rounded off to two decimal places).

Type a number as your answer.

Assuming that there are 5 × 10¹³ cells in the human body, and that ATP is turning over at a rate of 10⁹ ATP molecules per minute in each cell, then the human body is utilizing ________ watts (rounded off to two decimal places).

[Assume that hydrolysis of ATP yields 12 kcal per mole. 1 watt = 1 joule/sec, 1 calorie = 4.18 joules, Avogadro’s number = 6.023 × 10²³]

Type a number as your answer.

A solution shows a transmittance of 20% when taken in a cuvette of 2.5 cm path length. If the molar absorption coefficient of the solution is 12000 dm³/mol.cm, the concentration of the solution is ______ × 10⁵ mol/dm³ (rounded off to two decimal places).

Type a number as your answer.

Which one of the following plant families is characterized by the gynobasic style of female reproductive organ?

1. ALamiaceae
2. BEuphorbiaceae
3. CMalvaceae
4. DPoaceae

Which one of the following plant organs typically exhibits all the four features listed below? (i) Starch-enriched endodermis (ii) Conjoint, collateral and open vascular bundle (iii) Endarch xylem (iv) Presence of medullary rays

1. ADicot root
2. BMonocot root
3. CDicot leaf
4. DDicot stem

Correctly match the following molecules/methods in Group-I with their major uses in Group-II.

1. AP−1; Q−3; R−2; S−4
2. BP−3; Q−1; R−4; S−2
3. CP−3; Q−1; R−2; S−4
4. DP−1; Q−3; R−4; S−2

Which one of the following commercial products is used as a systemic fungicide to control plant diseases?

1. ACaptan
2. BPhaltan
3. CThiram
4. DBenomyl

Which one of the following terms best describes the plants that are adapted to grow in acidic soil?

1. AHalophytes
2. BOxylophytes
3. CLithophytes
4. DChasmophytes

Which of the following plant genera is/are example(s) of partial stem parasite?

1. AStriga
2. BOrobanche
3. CViscum
4. DCuscuta

Which of the following amino acids contain(s) only one chiral center?

1. ASerine
2. BThreonine
3. CIsoleucine
4. DLeucine

If an endosperm cell of a typical diploid angiosperm species has 15 chromosomes, then the number of chromosomes in a microspore mother cell of this species under normal circumstances would be___________ (in integer).

Type a number as your answer.

Which one of the following class(es) of genes, when deleted, would result in sepal formation in all the floral whorls of Arabidopsis, as per the rules of the typical ABC model of floral organ patterning?

1. AClass A only
2. BClass A and class B
3. CClass B and class C
4. DClass B only

Correctly match the following molecular assemblies in Group-I with their functions in Group-II.

1. AP−3; Q−4; R−1; S−2
2. BP−3; Q−4; R−2; S−1
3. CP−2; Q−4; R−3; S−1
4. DP−4; Q−1; R−2; S−3

Correctly match the following secondary metabolites in Group-I with their chemical classes in Group-II.

1. AP−1; Q−2; R−6; S−5; T−4
2. BP−2; Q−5; R−6; S−3; T−4
3. CP−2; Q−3; R−5; S−4; T−1
4. DP−2; Q−3; R−6; S−5; T−4

Correctly match the following plant diseases in Group-I with their causal organisms in Group-II.

1. AP−1; Q−2; R−4; S−3
2. BP−5; Q−1; R−4; S−2
3. CP−5; Q−2; R−4; S−1
4. DP−5; Q−3; R−1; S−2

Correctly match the following plant species in Group-I with their main economically important products in Group-II.

1. AP−3; Q−4; R−1; S−5
2. BP−3; Q−4; R−1; S−2
3. CP−2; Q−4; R−1; S−3
4. DP−3; Q−1; R−2; S−5

Two genes X and Y are involved in root development in such a way that all the following three homozygous mutants show rootless phenotype.

(i) Gain-of-function mutant of X
(ii) Loss-of-function mutant of Y
(iii) Double mutant of gain-of-function of X and loss-of-function of Y

Which one of the following genetic pathways best describes these observations?

1. AX suppresses Y and Y promotes root development
2. BX promotes Y and Y promotes root development
3. CX suppresses Y and Y supresses root development
4. DX promotes Y and Y supresses root development

Which of the following combinations of photosynthetic carbon cycle in plants, and its matched biochemical reaction is/are correct?

1. AC3 pathway : Ribulose 1,5-bisphosphate + CO₂ + H₂O → 2 3-phosphoglycerate
2. BC2 pathway : 2 Glycolate + 2 O₂ → 2 glyoxylate + 2 H₂O₂
3. CC4 pathway : 2 2-Phosphoglycolate + 2 H₂O → 2 glycolate + 2 P_i
4. DCAM pathway : Phosphoenolpyruvate + HCO₃⁻ → oxaloacetate + P_i

Choose the correct combination(s) of alkaloid, source plant, and their main commercial use.

1. AVincristine – Catharanthus roseus – anticancer drug
2. BScopolamine – Hyoscyamus niger – anticholinergic drug
3. CCocaine – Conium maculatum – antimalarial drug
4. DPilocarpine – Eschscholzia californica – antidepressant drug

Which of the following statements is/are correct about plant movement?

1. ADiaheliotropic refers to orienting the leaves perpendicular to the rays of the sun to maximize light interception.
2. BParaheliotropic refers to orienting the leaves parallel to the rays of the sun to minimize light interception.
3. CDiaheliotropic refers to orienting the leaves parallel to the rays of the sun to minimize light interception.
4. DParaheliotropic refers to orienting the leaves perpendicular to the rays of the sun to maximize light interception.

Two completely linked genes A and B regulate plant height and flower colour, respectively, wherein the recessive mutant aa is dwarf bearing red flowers and the recessive mutant bb is tall bearing white flowers. If an F1 individual of the aaBB × AAbb cross is crossed to the mutant aabb, then the probability of an individual in the next generation bearing white flower would be ___________ (Round off to two decimal places).

Type a number as your answer.

An enzyme following Michaelis-Menten kinetics, catalyses a reaction with an initial velocity (V₀) of 2 µM s⁻¹ at the substrate concentration of 10 µM. If the turnover number (k_cat) of the enzyme for the given substrate is 500 s⁻¹ and the enzyme concentration in the reaction is 0.01 µM, then the value of the Michaelis-Menten constant (K_m) would be___________ × 10⁻⁶ M (in integer).

Type a number as your answer.

Which one of the following statements about microbiological stains is CORRECT?

1. AAcid-fast stain is a simple stain.
2. BGram stain is used to visualize endospores.
3. CMethylene blue is an acidic dye.
4. DIndia ink is used to visualize capsules.

The genome of which one of the following viruses encodes reverse transcriptase?

1. AHuman immunodeficiency virus
2. BInfluenza virus
3. CPoliovirus
4. DRabies virus

Protoplasts can be generated from

1. AStreptococcus pneumoniae.
2. BBrucella abortus.
3. CPasteurella multocida.
4. DShigella flexneri.

Which one of the following molecules is the master regulator of the planktonic- surface transition in Pseudomonas aeruginosa during biofilm formation?

1. ACyclic thiolactone
2. BCyclic dimeric guanosine monophosphate
3. CCyclic triadenylate
4. DCyclohexamide

Which one of the following is a protozoal disease?

1. ACholera
2. BGonorrhea
3. CKala-azar
4. DSyphilis

Which one of the following drugs is a viral protease inhibitor?

1. AAcyclovir
2. BNevirapine
3. CRitonavir
4. DZidovudine

In Escherichia coli, the minimum number of crossovers required between F⁻ genome and the linear DNA transmitted by Hfr to form a viable recombinant is _____. (Answer in integer)

Type a number as your answer.

The decimal reduction time of Escherichia coli at a particular temperature is one minute. Assuming no bacterial growth and constant death rate, the time required for one million bacteria to get reduced to one viable bacterium is _____minutes. (Answer in integer)

Type a number as your answer.

Which one of the following options correctly matches the microbial names in Column I with their corresponding sources of epithet in Column II?

1. AP-i; Q-ii; R-iii; S-iv
2. BQ-i; R-ii; S-iii; P-iv
3. CR-i; S-ii; P-iii; Q-iv
4. DS-i; Q-ii; P-iii; R-iv

Determine the correctness or otherwise of the following Assertion [a] and the Reason [r].

Assertion [a]: Silver and copper display bacteriocidal or antiseptic activity.

Reason [r]: Silver and copper effectively demonstrate oligodynamic action.

1. ABoth [a] and [r] are true and [r] is the correct reason of [a].
2. BBoth [a] and [r] are true but [r] is not the correct reason of [a].
3. CBoth [a] and [r] are false.
4. D[a] is true but [r] is false.

When tryptophan level is low in Escherichia coli, the expression of tryptophan biosynthesis genes is turned on through an antiterminator stem-loop formation between

1. Aregions 1 and 2 of the leader sequence (trpL) of mRNA.
2. Bregions 2 and 3 of the leader sequence (trpL) of mRNA.
3. Cregions 2 and 4 of the leader sequence (trpL) of mRNA.
4. Dregions 3 and 4 of the leader sequence (trpL) of mRNA.

The effect of mutations in a gene at their transcriptional and translational levels were analyzed using Northern (N) and Western (W) blot techniques, respectively. The following figure shows the schematic representation of mRNA and protein expression profiles of the wild-type and its four different mutants. Which one of the following mutants contains mutation in the upstream regulatory region of the gene?

1. AMutant-1
2. BMutant-2
3. CMutant-3
4. DMutant-4

Which one of the following leukocytes is the most abundant in a healthy human?

1. ABasophils
2. BEosinophils
3. CMonocytes
4. DNeutrophils

DNA amplification in the polymerase chain reaction is

1. Alinear.
2. Bparabolic.
3. Csigmoidal.
4. Dexponential.

In bacteriophage lambda (λ) life cycle, binding of Cro protein to cI gene operator region

1. Aactivates cI gene expression.
2. Bdirects towards the lysogenic state.
3. Cdirects towards the lytic cycle.
4. Dprevents cI gene expression.

Which of the following is/are ring(s) of bacterial flagellum?

1. AC ring
2. BL ring
3. CP ring
4. DZ ring

Which of the following bacteria is/are uncultivable?

1. ABorrelia burgdorferi
2. BLeptospira interrogans
3. CMycobacterium leprae
4. DTreponema pallidum

Which of the following antibiotic(s) inhibit(s) bacterial protein synthesis?

1. AErythromycin
2. BTetracycline
3. CBacitracin
4. DVancomycin

Scientist(s) who contributed in disproving the theory of spontaneous generation is/are

1. AFerdinand Cohn.
2. BJohn Needham.
3. CJohn Tyndall.
4. DLouis Pasteur.

A researcher sets up ten large outdoor tanks, each containing the same amount of algae and the same number of guppies (herbivorous fish). In five of these tanks, she also adds gourami fish, which are predators of guppies. Tanks were covered in mesh so no new species could enter. After 2 months, the researcher counted the number of guppies and gouramies, and measured the amount of algae. She found that the amount of algae was much higher in the tanks with gourami fish compared to those without gourami fish. Which one of the following processes best explains the differences in amounts of algae between these tanks?

1. ACompetition-colonisation trade-off
2. BCompetitive exclusion principle
3. CInterference competition
4. DTrophic cascade

Immunoglobulins are classified into the following isotypes: IgG, IgM, IgA, IgD, IgE. What region of the immunoglobulin is used to determine this classification?

1. AThe constant region of the heavy chain only
2. BThe constant region of the light chain only
3. CThe variable region of both the heavy and light chains
4. DThe constant region of both the heavy and light chains

Correctly match the cell types in Column I to their primary function in Column II.

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

Which one of the following groups includes at least one animal that is NOT an arthropod?

1. AGroup 1: crustaceans, scorpions, mites, insects
2. BGroup 2: trilobites, horseshoe crabs, centipedes
3. CGroup 3: millipedes, horseshoe crabs, sponges, earthworms
4. DGroup 4: butterflies, moths, beetles

Females of many insect species mate with multiple different males. Which of the following is/are an adaptive explanation(s) for multiple mating in insects?

1. AFemales obtain more resources by mating with multiple males
2. BMultiple mating increases the genetic variation among the offspring
3. CMultiple mating increases the probability of fertilization
4. DMultiple mating increases relatedness among the offspring

Which one or more of the following terms describe(s) Toxoplasma gondii?

1. AVirus
2. BParasite
3. CBacteria
4. DFungus

Which of the following statements is/are NOT correct about the technique used in molecular biology?

1. ASouthern blotting is used to detect specific DNA sequences
2. BNorthern blotting is used to detect RNA expression levels
3. CWestern blotting is used to detect proteins using antibodies
4. DELISA is used to detect specific DNA sequences directly without antibodies

Assume that in the oxidative branch of the pentose phosphate pathway, each glucose-6-phosphate molecule generates the following products: 2 molecules of NADPH, 1 molecule of CO₂ and 1 molecule of ribulose-5-phosphate. If 30 molecules of glucose-6-phosphate enter this pathway, and you randomly draw one molecule from the products of the pathway, the probability that this molecule is NADPH is __________ (round off to one decimal place).

Type a number as your answer.

Muscle performance is positively correlated with Darwinian fitness. The graph below describes the relationship between mean environmental temperature and muscle performance for two closely related lizard species, one living in temperate areas (solid line) and another living in tropical areas (dashed line). Current mean environmental temperatures are marked with vertical dotted lines at (i) for the temperate species and (ii) for the tropical species. If mean environmental temperatures at both locations increase at a steady rate over time, which one of the following is most likely to occur in the near future?

1. ATemperate and tropical species will be negatively impacted to the same extent
2. BTemperate species may be positively impacted but tropical species will be negatively impacted
3. CTemperate species will be negatively impacted but tropical species will be positively impacted
4. DNeither temperate nor tropical species will be impacted

In eukaryotic cells, a mutation reduces the enzymatic activity of pyruvate dehydrogenase by 90%, without affecting expression. Under aerobic conditions, which one of the following metabolic changes is most expected in cells with the mutation compared to cells without?

1. AMutated cells will accumulate pyruvate and increase lactate production, despite oxygen being available
2. BMutated cells will have higher metabolic flux through Krebs cycle, resulting in higher NADH yield
3. CThis mutation will have no effect on metabolism
4. DMutated cells will have depleted levels of pyruvate and lactate, despite oxygen being available

Which one of the following describes the role of enhancers in eukaryotic gene regulation?

1. AEnhancers always lie immediately upstream of the promoter and function only in a fixed orientation
2. BEnhancers can act at variable distances from the promoters and may function upstream, downstream, or within introns of genes
3. CEnhancers directly bind to RNA polymerase II to initiate transcription
4. DEnhancers overlap with the RNA polymerase II binding site

Retes are networks of outgoing arteries and returning veins that create a counter-current pattern. Retes in the flippers of seals that live in temperate areas function as

1. Asensitivity enhancers to increase pain sensitivity in the flippers.
2. Bmetabolism blockers to prevent excess nutrients from being made in the flippers.
3. Cheat blocks to prevent body heat from being lost to the flippers.
4. Dpressure enhancers to spike blood pressure in the flippers.

Researchers measure the activity of an enzyme in the presence of an inhibitor. They observe that

• V_max of the enzyme remains unchanged at saturating substrate concentration
• K_m increases compared to uninhibited enzyme

Which type of inhibition is most consistent with these observations?

1. ACompetitive inhibition
2. BNon-competitive inhibition
3. CIrreversible inhibition
4. DSubstrate inhibition

Below are the numbers of individuals of migratory green warblers and the frequencies of three genotypes at a single locus for this species. F refers to the allele for faster migration and S to the allele for slower migration.

What are the allele frequencies of F and S? (round off to 2 decimal places)

1. AAllele frequency of F = 0.69 and allele frequency of S = 0.31
2. BAllele frequency of F = 0.59 and allele frequency of S = 0.41
3. CAllele frequency of F = 0.31 and allele frequency of S = 0.69
4. DAllele frequency of F = 0.50 and allele frequency of S = 0.50

A drug was developed to inhibit histone acetyl transferase in eukaryotic cells. Cells treated with this drug have more compact chromatin and show reduction in transcription of several genes. Which one of the following statements best explains why the drug has this effect?

1. AHistone acetylation increases positive charge on histones, thereby tightening DNA binding and repressing transcription
2. BHistone H1 directly binds the nucleosome core and its acetylation directly causes nucleosome disassembly
3. CHistone acetylation neutralizes positive charge on histones, thereby loosening DNA-histone interactions and promoting transcription
4. DEuchromatin is normally condensed, so reduced acetylation of histones converts it into a transcriptionally active state

Two species of snakes, Species P and Species Q, have overlapping geographic distributions. Species P mainly eats rodents, whereas Species Q mainly eats invertebrates. Which one or more of the following terms describe(s) the process of speciation for these two species?

1. ASympatric speciation
2. BParapatric speciation
3. CAllopatric speciation
4. DNiche differentiation

In rivers that range in salinity (ppt) from low to high, researchers found that the aquatic snail species P (solid curve) and Q (dashed curve) were distributed according to the pattern illustrated in figure (i) when the species are together. The researchers then conducted a manipulative experiment in similar rivers with the same salinity range, where they removed either species P or Q. Figure (ii) illustrates the number of individuals of species P and Q when they were allowed to live alone. These snails have no other competitors or predators. Which one or more conclusions can be drawn from these two figures?

1. AFundamental niche of P is larger than fundamental niche of Q
2. BFundamental niche of Q is larger than realized niche of Q
3. CFundamental niche of P is larger than realized niche of P
4. DFundamental and realized niches of P are the same

Which of the following statements is/are correct for the phylogenetic tree depicted below?

1. ASpecies R and Species S are reciprocally monophyletic
2. BSpecies R is sister to a clade comprised of Species P and Q
3. CSpecies P and Species Q are reciprocally monophyletic
4. DSpecies P, Q, R and S share a common ancestor

In her exploration of the Western Ghats, Dora finds four new species of fungi. Below is the DNA sequence alignment for a single locus from these new species that she calls Yeti, Unicorn, Bigfoot and Godzilla. Using the principle of parsimony and the DNA sequence alignment information below, which one or more of the following tree topologies represent(s) the relationship between these species?

Yeti: ATGC
Unicorn: ATGT
Bigfoot: ATGA
Godzilla: ATGT

1. AP
2. BQ
3. CR
4. DS

Ergotism is caused by ingestion of grains infected with

1. AClostridium perfringens
2. BRhizopus stolonifer
3. CLactococcus lactis
4. DClaviceps purpurea

Match the bacteria in Column I with their respective characteristic features in Column II.

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

Carmine, a food colorant, is derived from

1. ACurcuma longa
2. BDactylopius coccus
3. CBeta vulgaris
4. DMonascus purpureus

Which one of the following carbohydrates is NOT a storage polysaccharide?

1. AStarch
2. BGlycogen
3. CChitin
4. DDextran

Which one of the following statements is true for a high-pressure homogenizer?

1. AHomogenization takes place only due to uniform mixing of solid and liquid
2. BSolid particles in the suspension are disintegrated due to the high shear rate exerted by the liquid
3. CHigh pressure steam is injected to dissolve the solids
4. DSolid particles in the suspension are compressed into a cake under high pressure

Coconut oil contains a small fraction of unsaturated fatty acids, but still has a low melting point due to the presence of

1. Alarge amounts of long chain saturated fatty acids
2. Bmostly medium chain saturated fatty acids such as lauric acid
3. Cfew hydrogen bonds per fatty acid chain
4. Dhigher cholesterol content

Which of the following amines, produced as a result of protein degradation, is/are foul smelling?

1. AHistamine
2. BCadaverine
3. CTyramine
4. DPutrescine

Water is flowing at 100 litres/min through a pipe with a diameter of 5 cm. Assume the coefficient of viscosity of water to be 0.001 Pa.s and the density to be 1000 kg/m³. The Reynolds number for this flow is _______ (Round off to nearest integer)

Type a number as your answer.

Match the toxins in Column I with their respective sources in Column II.

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

Match the vitamins in Column I with their respective coenzyme forms listed in Column II.

1. AP-3; Q-4; R-5; S-2; T-1
2. BP-4; Q-3; R-1; S-5; T-2
3. CP-1; Q-5; R-4; S-2; T-3
4. DP-5; Q-2; R-4; S-3; T-1

Which one of the following proteins brings about the coagulation of milk in the stomach of calves?

1. ARennin
2. BAlpha-lactalbumin
3. CBeta-lactoglobulin
4. DLactoferrin

Match the class of additives used for food preservation listed in Column I with their specific examples in Column II.

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

Match the food items listed in Column I with their respective flavoring agents in Column II.

1. AP-1; Q-3; R-2; S-4; T-5
2. BP-3; Q-2; R-1; S-5; T-4
3. CP-4; Q-2; R-5; S-1; T-3
4. DP-3; Q-1; R-2; S-5; T-4

Vegetable oils resist oxidation and maintain their quality for a long period due to the presence of

1. Atocopherols
2. Bhydrolytic enzyme such as lipases
3. Cmicroorganisms such as molds and yeast
4. Dcarbohydrates

For a given temperature difference between the top and bottom surfaces of a flat metal plate, Fourier’s law of heat conduction implies that

1. Atemperature gradient increases with increase in heat transfer area
2. Bheat flux is proportional to the thermal conductivity of the metal
3. Cheat flux increases with increase in thickness of the metal plate
4. Dtemperature gradient decreases with increase in thickness of the metal plate

Xylooligosaccharides can be produced by

1. Ahydrolytic degradation of xylan by hydrochloric acid
2. Bhydrolysis of starch
3. Cenzymatic hydrolysis of lactose
4. Denzymatic hydrolysis of xylan containing lignocellulosic material

In a α-helix, the R-groups on the amino acid residues

1. Aare found on the outside of the helix
2. Bparticipate in the backbone H-bonding that stabilize the helix
3. Callow formation of right-handed helices
4. Dallow formation of left-handed helices

During constant pressure cake filtration, for an incompressible cake deposited uniformly over a constant filter surface area,

1. Athe cake resistance remains constant
2. Bthe cake resistance increases in proportion to the cake thickness
3. Cthe filtration rate remains constant
4. Dthe filtration rate decreases with time

Hot oil is being cooled in a countercurrent, double-pipe heat exchanger from 410 K to 340 K by chilled water entering at 290 K and exiting the exchanger at 330 K. The Log Mean Temperature Difference (LMTD) for this heat transfer is ________K. (Round off to one decimal place)

Type a number as your answer.