GATE 2021 Question Paper BT Biotechnology

General Aptitude (GA)
Q.1 – Q.5 Multiple Choice Question (MCQ), carry ONE mark each (for each wrong
answer: – 1/3).

Q.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:

(A) 21

(B) 37

(C) 50

(D) 73

Q.2 A polygon is convex if, for every pair of points, P and Q belonging to the
polygon, the line segment PQ lies completely inside or on the polygon.
Which one of the following is NOT a convex polygon?

(A)

(B)

(C)

(D)

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Q.3 Consider the following sentences:
(i) Everybody in the class is prepared for the exam.
(ii) Babu invited Danish to his home because he enjoys playing
chess.
Which of the following is the CORRECT observation about the above two
sentences?

(A) (i) is grammatically correct and (ii) is unambiguous

(B) (i) is grammatically incorrect and (ii) is unambiguous

(C) (i) is grammatically correct and (ii) is ambiguous

(D) (i) is grammatically incorrect and (ii) is ambiguous

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Q.4

A circular sheet of paper is folded along the lines in the directions shown.
The paper, after being punched in the final folded state as shown and
unfolded in the reverse order of folding, will look like _______.

(A)

(B)

(C)

(D)

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Q.5 _____ is to surgery as writer is to ________
Which one of the following options maintains a similar logical relation in
the above sentence?

(A) Plan, outline

(B) Hospital, library

(C) Doctor, book

(D) Medicine, grammar

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Q. 6 – Q. 10 Multiple Choice Question (MCQ), carry TWO marks each (for each wrong
answer: – 2/3).

Q.6 We have 2 rectangular sheets of paper, M and N, of dimensions 6 cm x 1 cm
each. Sheet M is rolled to form an open cylinder by bringing the short edges
of the sheet together. Sheet N is cut into equal square patches and assembled
to form the largest possible closed cube. Assuming the ends of the cylinder
are closed, the ratio of the volume of the cylinder to that of the cube is
__________

(A) 𝜋
2
(B) 3
𝜋
(C) 9
𝜋
(D) 3𝜋

Q.7
Items Cost Profit % Marked Price
(₹) (₹)

P 5,400 --- 5,860

Q --- 25 10,000

Details of prices of two items P and Q are presented in the above table. The ratio
of cost of item P to cost of item Q is 3:4. Discount is calculated as the difference
between the marked price and the selling price. The profit percentage is
calculated as the ratio of the difference between selling price and cost, to the cost
Selling price−Cost
(Profit % = × 100).
Cost
The discount on item Q, as a percentage of its marked price, is ______

(A) 25

(B) 12.5

(C) 10

(D) 5

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Q.8 There are five bags each containing identical sets of ten distinct chocolates.
One chocolate is picked from each bag.
The probability that at least two chocolates are identical is ___________

(A) 0.3024

(B) 0.4235

(C) 0.6976

(D) 0.8125

Q.9 Given below are two statements 1 and 2, and two conclusions I and II.
Statement 1: All bacteria are microorganisms.
Statement 2: All pathogens are microorganisms.
Conclusion I: Some pathogens are bacteria.
Conclusion II: All pathogens are not bacteria.
Based on the above statements and conclusions, which one of the following
options is logically CORRECT?

(A) Only conclusion I is correct

(B) Only conclusion II is correct

(C) Either conclusion I or II is correct.

(D) Neither conclusion I nor II is correct.

Q.10 Some people suggest anti-obesity measures (AOM) such as displaying
calorie information in restaurant menus. Such measures sidestep
addressing the core problems that cause obesity: poverty and income
inequality.
Which one of the following statements summarizes the passage?

(A) The proposed AOM addresses the core problems that cause obesity.

(B) If obesity reduces, poverty will naturally reduce, since obesity causes poverty.

(C) AOM are addressing the core problems and are likely to succeed.

(D) AOM are addressing the problem superficially.

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Q.1 – Q.17 Multiple Choice Question (MCQ), carry ONE mark each (for each wrong
answer: – 1/3).

Q.1 Coronavirus genome consists of

(A) double-stranded DNA

(B) double-stranded RNA

(C) negative-sense single-stranded RNA

(D) positive-sense single-stranded RNA

Q.2 The enzyme that transcribes the eukaryotic genes encoding precursor
ribosomal RNAs (pre-rRNAs) of 28S, 18S and 5.8S rRNAs is

(A) RNA polymerase I

(B) RNA polymerase II

(C) RNA polymerase III

(D) RNA polymerase IV

Q.3 Number of unrooted trees in a phylogeny of five sequences is

(A) 3

(B) 15

(C) 105

(D) 945

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Q.4 Which one of the following methods is used to test the significance of a
predicted phylogeny?

(A) Bootstrap

(B) Maximum likelihood

(C) Maximum parsimony

(D) Minimum evolution

Q.5
(
The Cartesian coordinates ( x, y ) of a point A with polar coordinates 4,  4 )
is

(A)
( 3, 2 2 )
(B)
( 2, 2 3 )
(C)
( 2 2, 3 )
(D)
( 2 2, 2 2 )

Q.6 The order of genes present in a chromosome is as follows.

L M N O P Q

Which one of the following rearrangements represents a paracentric inversion?

(A) L O N M P Q

(B) L M N P O Q

(C) L M M N N O P Q

(D) L M N O P Q

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Q.7 Which one of the following statements is INCORRECT about hybridoma
production?

(A) Hybridoma cells can use hypoxanthine and thymidine

(B) DNA synthesis in myeloma cells is blocked by aminopterin

(C) Hybridoma cells are made to produce polyclonal antibodies

(D) Polyethylene glycol is used to fuse myeloma cells to B-cells

Q.8 d
ln ( 2 x )  is equal to
dx 

(A) 1
2x

(B) 1
x

(C) 1
2

(D) x

Q.9 Which one of the following techniques/tools is NOT used for inserting a foreign
gene into a cell?

(A) DNA microarray

(B) Electroporation

(C) Gene gun

(D) Microinjection

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Q.10 Under standard temperature ( T ) and pressure ( P ) conditions, 128 g of an
ideal gas molecule A occupies a volume of 1L . The gas molecule A obeys the
relationship RT = 0.25PV . R and V are universal gas constant and ideal gas
volume, respectively. The molecule A is

(A) CO2

(B) H2

(C) N2

(D) O2

Q.11 CRISPR-Cas system is associated with

(A) adaptive immunity in eukaryotes

(B) adaptive immunity in prokaryotes

(C) innate immunity in eukaryotes

(D) innate immunity in prokaryotes

Q.12 The process by which intracellular macromolecules are supplied for lysosomal
degradation during nutrient starvation is

(A) apoptosis

(B) autophagy

(C) phagocytosis

(D) pinocytosis

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Q.13 The process and instrumentation diagram for a feedback control strategy to
maintain the level ( h ) of a liquid by regulating a valve (V ) in a tank is shown
below. F1 is inlet liquid flow rate, F2 is outlet liquid flow rate, LT is the liquid
level transmitter, LC is the liquid level controller, hsp is the setpoint value of
the liquid level, hm is the measured value of the liquid level and PV is the valve
pressure.

The manipulating variable(s) is/are

(A) F1 only

(B) F2 only

(C) hm and PV only

(D) hsp and PV only

Q.14 A protein without its prosthetic group is known as

(A) apoprotein

(B) hemoprotein

(C) holoprotein

(D) lipoprotein

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Q.15 The enzyme which adds phosphate group to the free 5 terminus of a DNA
sequence is

(A) adenosine kinase

(B) alkaline phosphatase

(C) polynucleotide kinase

(D) terminal deoxynucleotidyl transferase

Q.16 Which one of the following is CORRECT about microbial growth medium?

(A) Luria-Bertani broth is a synthetic medium

(B) Nutrient broth is a defined medium

(C) Sabouraud dextrose agar is a differential medium

(D) Trypticase soy agar is a complex medium

Q.17 The cellular process which utilizes RNA-induced silencing complex to block
gene expression is

(A) RNA editing

(B) RNA interference

(C) RNA polyadenylation

(D) RNA splicing

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Q.18 – Q.19 Multiple Select Question (MSQ), carry ONE mark each (no negative marks).

Q.18 Which of the following layer(s) is/are formed from the inner cell mass of the
blastocyst?

(A) Ectoderm

(B) Endoderm

(C) Mesoderm

(D) Trophectoderm

Q.19 Which of the following cell organelle(s) is/are surrounded by a single
phospholipid membrane?

(A) Golgi apparatus

(B) Lysosome

(C) Mitochondria

(D) Nucleus

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Q.20 – Q.25 Numerical Answer Type (NAT), carry ONE mark each (no negative marks).

Q.20 The sum of the infinite geometric series 1 + 1 + 1 2 + 1 3 + ... (rounded off to
3 3 3
one decimal place) is ________.

Q.21 Three balls, colored in blue, green and red, are successively transferred from
box A to box B in the order BLUE-GREEN-RED. The probability of a reverse
transfer of the balls to the box A in the same order (rounded off to two decimal
places)
is ________.

Q.22 Decimal reduction time of a bacterial strain is 20 min . Specific death rate
constant in min−1 (rounded off to two decimal places) is ________.

Q.23  x − sin2 x 
The value of lim  (rounded off to two decimal places) is ________.
x →0  x − sin5 x 


Q.24 A system consists of two reactors, connected by a valve. The first reactor ( R1 )
contains an ideal gas A of volume 5 L and the second reactor ( R2 ) has an ideal
gas B of volume 10 L . Initially, the valve is closed and pressure P in R1 and
R2 are 9 and 6 atm , respectively. Later, when the valve is opened, the system
reaches equilibrium. If the temperature T of both the reactors is maintained
constant, the final equilibrium pressure in atm of the system is ________.

Q.25 The enzyme α-amylase used in starch hydrolysis has an affinity constant ( K m )
value of 0.005 M . To achieve one-fourth of the maximum rate of hydrolysis,
the required starch concentration in mM (rounded off to two decimal places)
is ________.

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Q.26 – Q.34 Multiple Choice Question (MCQ), carry TWO mark each (for each wrong
answer: – 2/3).

Q.26 Which one of the following represents non-growth associated product
formation kinetics in a bioprocess system? X and P denote viable cell and
product concentrations, respectively.

(A) X
Concentration

P

Time

(B)
X
Concentration

P

Time

(C)
X
Concentration

P

Time

(D) X
Concentration

P

Time

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Q.27 Match enzymes in Group I with their corresponding industrial application
in Group II.

Group I Group II

P. Amylase 1. Laundry detergent

Q. Invertase 2. Fruit juice clarification

R. Pectinase 3. Liquefaction of sucrose

S. Xylanase 4. Pulp and paper processing

(A) P-2, Q-3, R-4, S-1

(B) P-1, Q-3, R-2, S-4

(C) P-1, Q-2, R-3, S-4

(D) P-1, Q-4, R-2, S-3

Q.28 Match separation methods in Group I with associated properties in Group
II.

Group I Group II

P. Centrifugation 1. Density

Q. Dialysis 2. Diffusivity

R. Solvent extraction 3. Size

S. Ultrafiltration 4. Solubility

(A) P-4, Q-2, R-1, S-3

(B) P-3, Q-1, R-2, S-4

(C) P-1, Q-3, R-2, S-4

(D) P-1, Q-2, R-4, S-3

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Q.29 Match the autoimmune diseases in Group I with the corresponding
primarily affected organ in Group II.

Group I Group II

P. Hashimoto’s disease 1. Brain

Q. Juvenile diabetes 2. Pancreas

R. Multiple sclerosis 3. Skeletal muscle

S. Myasthenia gravis 4. Thyroid

(A) P-1, Q-2, R-3, S-4

(B) P-3, Q-1, R-2, S-4

(C) P-4, Q-2, R-1, S-3

(D) P-1, Q-2, R-4, S-3

Q.30 Match hypersensitivity types in Group I with their corresponding condition
in Group II.

Group I Group II

P. Type I 1. Erythroblastosis fetalis

Q. Type II 2. Host reaction to bee venom

R. Type III 3. Systemic lupus erythematosus

S. Type IV 4. Tuberculin reaction

(A) P-2, Q-3, R-1, S-4

(B) P-3, Q-1, R-4, S-2

(C) P-2, Q-3, R-4, S-1

(D) P-2, Q-1, R-3, S-4

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Q.31 Which of the following combinations of plant hormones and their associated
function are CORRECT?

Hormone Function

P. Abscisic acid Breaks seed dormancy

Q. Auxin Induces cell division

R. Ethylene Stimulates ripening of fruits

S. Gibberellin Promotes seed dormancy

(A) P and R only

(B) P and S only

(C) Q and R only

(D) Q and S only

Q.32 Which one of the following tools is used to compare all the possible six-open
reading frames of a given nucleotide query sequence with all the available
six-open reading frames of the nucleotide sequence database?

(A) BLASTN

(B) BLASTX

(C) TBLASTN

(D) TBLASTX

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Q.33 In Neurospora crassa, a mutation in the poky gene results in a slow growth
phenotype (poky). The results of four crosses are given below.
(1) wild-type ♀ × wild-type ♂ → All progeny are wild-type
(2) wild-type ♀ × poky ♂ → All progeny are wild-type
(3) poky ♀ × wild-type ♂ → All progeny are poky
(4) poky ♀ × poky ♂ → All progeny are poky
Which one of the following explains the inheritance mode of poky?

(A) Episomal inheritance

(B) Mendelian inheritance

(C) Mitochondrial inheritance

(D) X-linked inheritance

Q.34 Tertiary structure of a protein consisting of α-helices and β-strands can be
determined by

(A) circular dichroism spectroscopy

(B) mass spectrometry

(C) nuclear magnetic resonance spectroscopy

(D) UV spectroscopy

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Q.35 – Q.38 Multiple Select Question (MSQ), carry TWO mark each (no negative marks).

Q.35 Which of the following statement(s) is/are CORRECT about Agrobacterium
tumefaciens?

(A) It contains tumor inducing plasmid

(B) It causes crown gall disease in dicotyledonous plants

(C) It is a Gram-positive soil bacterium

(D) It is used in generating transgenic plants

Q.36 Which of the following antimicrobial agent(s) is/are growth factor analog(s)?

(A) 5-Fluorouracil

(B) Isoniazid

(C) Sulfanilamide

(D) Tetracycline

Q.37 Which of the following chemical messenger(s) is/are derivative(s) of
tryptophan?

(A) γ-amino butyric acid

(B) Indole acetic acid

(C) Melatonin

(D) Serotonin

Q.38 Which of the following nucleus/nuclei is/are NMR active?
1
(A) H
13
(B) C
16
(C) O
32
(D) S

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Q.39 – Q.55 Numerical Answer Type (NAT), carry TWO mark each (no negative marks).

Q.39 In a Mendel’s dihybrid experiment, a homozygous pea plant with round
yellow seeds was crossed with a homozygous plant with wrinkled green
seeds.
F1 intercross produced 560 F2 progeny. The number of F2 progeny having
both dominant traits (round and yellow) is ________.

Q.40 A 0.1 mL aliquot of a bacteriophage stock having a concentration of
4 109 phages mL−1 is added to 0.5 mL of E. coli culture having a
concentration of 2 108 cells mL−1 . The multiplicity of infection is ________.

Q.41 If the area of a triangle with the vertices ( k , 0 ) , ( 2,0) and ( 0, − 2 ) is
2 square units, the value of k is ________.

Q.42 In a chemostat with a dilution rate of 0.8 h−1 , the steady state biomass
concentration and the specific product formation rate are 8 mol m −3 and
0.2 (mol product ) (mol biomass)−1 h −1 , respectively. The steady state product
concentration in mol m−3 is ________.

Q.43 If the values of two random variables ( X , Y ) are (121, 360 ) , ( 242, 364)
and ( 363, 362) , the value of correlation coefficient between X and Y
(rounded off to one decimal place) is ________.

Q.44 1 1 1 1
 
−1 1 1 1
The determinant of matrix A =  is ________.
 −1 −1 1 1
 
1 1 1 3

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Q.45 It is desired to scale-up a fermentation from 1L to 1000 L vessel by
maintaining a constant power-to-volume ratio. The small fermenter is
operated at an agitator speed of 300 rotations per minute (rpm) . If the value
of scale up factor is 10 , agitator speed in rpm (rounded off to the nearest
integer) for the large fermenter is ________.

Q.46 The specific growth rate of a mold during exponential phase of its growth in
a batch cultivation is 0.15 h −1 . If the cell concentration at 30 h is 33 g L−1 ,
the cell concentration in g L−1 (rounded off to the nearest integer) at 24 h is
________.

Q.47 A sedimentation tank of height 100 cm is used in a conventional activated
sludge process to separate a suspension of spherical shaped granular sludge
biomass of 0.5 mm diameter. The viscosity of the liquid is 1 cP . The
difference in density between the suspended biomass and the liquid is
0.1g cm−3 . If the biomass reach their terminal velocity instantaneously, the
biomass settling time in min (rounded off to two decimal places) is ________.

Q.48 In a random mating population, Y and y are dominant and recessive
alleles, respectively. If the frequency of Y allele in both sperm and egg is
0.70, then the frequency of Y y heterozygotes (rounded off to two decimal
places) is ________.

Q.49 Calculate the following integral
2
4

 sin x dx = ______ .
0

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Q.50 A feed stream ( F1 ) containing components A and B is processed in a system
comprising of separation unit and a mixer as shown below in the schematic
diagram. The mole fractions of the components A and B are x A and xB ,
respectively. If F1 + F2 = 100 kg h −1 , the degrees of freedom of the system
is ________.

Separation Mixer
unit

Q.51 A batch cultivation of E. coli follows zeroth order Monod’s growth kinetics.
The cell growth is terminated when the residual dissolved oxygen
concentration attains 10% of its saturation value and oxygen mass transfer
coefficient ( k L a ) reaches its maximum value ( 80 h −1 ) . The saturation value
of dissolved oxygen concentration is 0.007 kg m −3 . If the maximum specific
growth rate and yield coefficient (YX O ) are 0.2 h−1 and
2

−1
1.5 ( kg cells ) (kg O2 ) , respectively, then the final cell concentration in
kg m −3 (rounded off to two decimal places) at the end of the batch cultivation
is ________.

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Q.52 Milk flowing through a stainless steel inner tube (𝟒𝟎 𝒎𝒎 inner diameter) of
double tube-type heater is to be heated from 10 oC to 85 oC by saturated
steam condensing at 120 oC on the outer surface of the inner tube. Total heat
transferred ( Q ) is 𝟏𝟒𝟔𝟐𝟎𝟎 𝒌𝒄𝒂𝒍 𝒉−𝟏 and the overall heat transfer
∘
coefficient is 𝟕𝟓𝟎 𝒌𝒄𝒂𝒍 𝒉−𝟏 𝒎−𝟐 𝑪−𝟏 . The total length of the heating
tube in 𝒎 (rounded off to one decimal place) is ________.

Q.53 A DNA solution of 50  g mL−1 concentration gives an absorbance of 1.0 at
260nm . An aliquot of 20  L from a 50  L purified plasmid solution is
diluted with distilled water to a total volume of 1000  L . The diluted plasmid
solution gives an absorbance of 0.550 at 260nm . The concentration of the
purified plasmid in  g  L−1 (rounded off to two decimal places) is ________.

Q.54 The possible number of SalI restriction sites in a 9 kb double-stranded DNA,
with all four bases occurring in equal proportion (rounded off to the nearest
integer)
is ________.

Q.55 A bacterium produces acetic acid from ethanol as per the following reaction
𝟐𝑪𝑯𝟑 𝑪𝑯𝟐 𝑶𝑯 + 𝟐𝑶𝟐 → 𝟐𝑪𝑯𝟑 𝑪𝑶𝑶𝑯 + 𝟐𝑯𝟐 𝑶
The thermodynamic maximum yield of acetic acid from ethanol in g g −1
(rounded off to two decimal places) is ________.

END OF THE QUESTION PAPER

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