GATE 2021 BT – Previous Year Questions with Solutions
All 65 questions of GATE 2021 BT with answers and explanations. Read each question, then practise it by topic or as a full paper.
Practise this paper in The GATE Grind →
- Question 1 – The ratio of boys to girls in a class is 7 to 3. Among the options below, an acceptable value for the total number of students in the class is:
- Question 2 – A polygon is convex if, for every pair of points P and Q belonging to it, segment PQ lies completely inside or on it. Which option is NOT convex?
- Question 3 – Consider: (i) Everybody in the class is prepared for the exam. (ii) Babu invited Danish to his home because he enjoys playing chess. Which observation…
- Question 4 – A circular sheet is folded in the directions shown and punched in its final folded state. Which option shows it unfolded in reverse order?
- Question 5 – is to surgery as writer is to . Which pair maintains a similar logical relation?
- Question 6 – Two rectangular sheets M and N are each 6 cm × 1 cm. M is rolled by joining its short edges to form a cylinder. N is cut into equal square patches and…
- Question 7 – The costs of P and Q have ratio 3:4. P costs ₹5400 and has marked price ₹5860. Q has profit 25% and marked price ₹10000. Discount is marked minus…
- Question 8 – Five bags contain identical sets of ten distinct chocolates. One chocolate is picked from each bag. The probability that at least two are identical is
- Question 9 – Statements: All bacteria are microorganisms. All pathogens are microorganisms. Conclusions: I. Some pathogens are bacteria. II. All pathogens are not…
- Question 10 – Some people suggest anti-obesity measures (AOM) such as displaying calorie information in restaurant menus. Such measures sidestep the core problems…
- Question 11 – Coronavirus genome consists of
- Question 12 – The enzyme transcribing eukaryotic genes encoding the precursor of 28S, 18S and 5.8S rRNAs is
- Question 13 – Number of unrooted trees in a phylogeny of five sequences is
- Question 14 – Which method tests the significance of a predicted phylogeny?
- Question 15 – The Cartesian coordinates of a point with polar coordinates (4,/4) are
- Question 16 – The original chromosome has gene order L M • N O P Q, where • is the centromere. Which rearrangement is a paracentric inversion?
- Question 17 – Which statement is INCORRECT about hybridoma production?
- Question 18 – d[(2x)]/dx is
- Question 19 – Which technique is NOT used for inserting a foreign gene into a cell?
- Question 20 – Under standard T and P, 128 g of ideal gas A occupies 1 L and obeys RT=0.25PV. R is the universal gas constant. A is
- Question 21 – CRISPR-Cas is associated with
- Question 22 – The process supplying intracellular macromolecules for lysosomal degradation during nutrient starvation is
- Question 23 – A feedback loop controls tank liquid level h by inlet valve V. F 1,F 2 are inlet and outlet flows, LT is transmitter, LC is controller, h sp is set…
- Question 24 – A protein without its prosthetic group is known as
- Question 25 – The enzyme adding phosphate to the free 5′ terminus of DNA is
- Question 26 – Which statement about microbial growth medium is correct?
- Question 27 – The process using RNA-induced silencing complex to block gene expression is
- Question 28 – Which layers form from blastocyst inner cell mass?
- Question 29 – Which organelles are surrounded by a single phospholipid membrane?
- Question 30 – The sum 1+1/3+1/32+1/33+ (one decimal place) is .
- Question 31 – Blue, green and red balls are transferred successively from A to B in that order. The probability of their reverse transfer to A in the same order…
- Question 32 – A bacterial strain has decimal reduction time 20 min. Specific death rate constant (min⁻¹, two decimal places) is .
- Question 33 – The value of x0(x-2x)/(x-5x) (two decimal places) is .
- Question 34 – Two reactors contain ideal gases: R1 has 5 L at 9 atm, R2 has 10 L at 6 atm. Opening their connecting valve at constant temperature gives equilibrium…
- Question 35 – α-amylase has K m=0.005 M. The starch concentration for one-fourth of maximum hydrolysis rate (mM, two decimal places) is .
- Question 36 – Which plot represents non-growth-associated product formation? X and P are viable-cell and product concentrations.
- Question 37 – Match P amylase, Q invertase, R pectinase and S xylanase to: 1 laundry detergent, 2 fruit-juice clarification, 3 liquefaction of sucrose, 4 pulp and…
- Question 38 – Match P centrifugation, Q dialysis, R solvent extraction and S ultrafiltration to: 1 density, 2 diffusivity, 3 size, 4 solubility.
- Question 39 – Match P Hashimoto’s disease, Q juvenile diabetes, R multiple sclerosis and S myasthenia gravis to: 1 brain, 2 pancreas, 3 skeletal muscle, 4 thyroid.
- Question 40 – Match P type I, Q type II, R type III and S type IV hypersensitivity to: 1 erythroblastosis fetalis, 2 host reaction to bee venom, 3 systemic lupus…
- Question 41 – Which hormone/function combinations are correct? P abscisic acid—breaks seed dormancy; Q auxin—induces cell division; R ethylene—stimulates fruit…
- Question 42 – Which tool compares all six reading frames of a nucleotide query with all six reading frames of a nucleotide database?
- Question 43 – Neurospora crosses yield: wild-type female × wild-type male → all wild-type; wild-type female × poky male → all wild-type; poky female × wild-type…
- Question 44 – Tertiary structure of a protein with α-helices and β-strands can be determined by
- Question 45 – Which statements about Agrobacterium tumefaciens are correct?
- Question 46 – Which antimicrobial agents are growth-factor analogs?
- Question 47 – Which chemical messengers are derivatives of tryptophan?
- Question 48 – Which nuclei are NMR active?
- Question 49 – A homozygous round-yellow pea is crossed with a homozygous wrinkled-green pea. F1 intercross produces 560 F2 progeny. The number with both dominant…
- Question 50 – 0.1 mL phage stock at 4109 phages/mL is added to 0.5 mL E. coli at 2108 cells/mL. Multiplicity of infection is .
- Question 51 – A triangle with vertices (k,0),(2,0),(0,-2) has area 2. The value of k is .
- Question 52 – A chemostat has D=0.8\ h-1, biomass 8 mol/m³ and specific product formation 0.2 mol product/(mol biomass h). Steady product concentration (mol/m³) is…
- Question 53 – For observations (X,Y)=(121,360),(242,364),(363,362), correlation coefficient (one decimal place) is .
- Question 54 – The determinant of A=pmatrix1&1&1&1\\-1&1&1&1\\-1&-1&1&1\\1&1&1&3pmatrix is .
- Question 55 – Fermentation is scaled from 1 L to 1000 L at constant power/volume. Small-vessel agitation is 300 rpm and linear scale factor is 10. Large-vessel…
- Question 56 – A mold grows exponentially at 0.15 h⁻¹. Its concentration at 30 h is 33 g/L. Concentration at 24 h (nearest integer g/L) is .
- Question 57 – A 100 cm sedimentation tank separates spherical sludge of diameter 0.5 mm. Liquid viscosity is 1 cP and density difference 0.1 g/cm³. Assuming…
- Question 58 – A randomly mating population has Y allele frequency 0.70 in sperm and eggs. The Y/y heterozygote frequency (two decimal places) is .
- Question 59 – Calculate 02/4x\,dx.
- Question 60 – A binary feed F 1 splits into F 2 bypass and F 3 separator feed. Separation gives F 4,F 5; mixer combines F 2,F 5 into F 6. Stream compositions are x…
- Question 61 – Batch E. coli has zero-order Monod growth. At termination dissolved O2 is 10% saturation and k La=80\ h-1. Saturation is 0.007 kg/m³, maximum growth…
- Question 62 – Milk in a stainless-steel inner tube (inner diameter 40 mm) is heated from 10°C to 85°C by steam condensing at 120°C. Heat transfer is 146200 kcal/h…
- Question 63 – DNA at 50 μg/mL has A260=1.0. A 20 μL aliquot from 50 μL purified plasmid is diluted to 1000 μL and gives A260=0.550. Purified plasmid concentration…
- Question 64 – The possible number of SalI restriction sites in 9 kb double-stranded DNA with equiprobable bases (nearest integer) is .
- Question 65 – For 2CH 3CH 2OH+2O 22CH 3COOH+2H 2O, the thermodynamic maximum acetic-acid yield from ethanol (two decimal places g/g) is .