GATE 2026 Question Paper Life Sciences (XL)

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GATE 2026
Question Paper · Life
Sciences (XL)
EXAM YEAR TYPE SUBJECT

GATE 2026 Question Paper Life Sciences (XL)

Notes · Sample Papers · Previous Year Papers · Mock Tests

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m .co s e m Life Sciences (XL)
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General Aptitude (GA)
Q.1 – Q.5 Carry ONE mark Each

Q.1 Suresh said, “I did it yesterday.”

Which one of the following options is the correct form of this sentence in indirect
m
.co
speech?
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.co s e m
s em l a
g la ag
(A) a Suresh said that I did it yesterday.

(B) Suresh says I did it yesterday.

(C) Suresh says that he did it the day before.

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.co
(D) Suresh said that he had done it the day before.

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ag

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m .co s e m
s e g l a
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a

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.co s e m
s em l a
la
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Life Sciences (XL)

Q.2 To continue the sequence of tiles shown, the tile indicated by the question mark
should be

(A)

(B)

(C)

(D)

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m .co s e m Life Sciences (XL)
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Q.3 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 ________.

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m .co s e m
s e l a
g l a ag
a

(A) 2
m
m .co
(B) 3
s e
g la
(C) 4 a
(D) 5

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m .co s e m
s e g l a
g la a
a

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.co s e m
s em l a
la
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Life Sciences (XL)

Q.4 The 2nd of June is a Thursday in a certain year. Which day of the week is the
3rd of July in that year?

(A) Thursday

(B) Friday

(C) Saturday

(D) Sunday

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m .co s e m Life Sciences (XL)
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Q.5 A coin with heads facing up is shown as and a coin with tails facing up is
shown as .

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
m
.co
to the Final Arrangement, as shown in the figure, is ________.
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s e l a
g l a ag
a

(A) 3

m
.co
(B) 6

e m
(C) 9
las
ag
(D) 12

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m .co s e m
s e g l a
g la a
a

m .
.co s e m
s em l a
la
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Life Sciences (XL)

Q.6 – Q.10 Carry TWO marks Each

Q.6 Exacerbate : Mitigate :: ___________

Choose the option with the correct pair of words to fill the blank.

(A) Aggravate : Alleviate

(B) Alleviate : Precipitate

(C) Aggravate : Precipitate

(D) Emancipate : Exonerate

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Q.7 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?

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g l a ag
a

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s e
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a
(A) Only (i) can correspond to the unfolded cube in Panel I.

(B) Only (ii) can correspond to the unfolded cube in Panel I.

(C) Both (i) and (ii) can correspond to the unfolded cube in Panel I.
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.co
(D) Neither (i) nor (ii) can correspond to the unfolded cube in Panel I.
e m
e m l as
las ag
ag

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.co s e m
s em l a
la
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Life Sciences (XL)

Q.8 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 _______

(A) 0

(B) 15

(C) 20

(D) 10

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m .co s e m Life Sciences (XL)
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Q.9 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. m
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m .co
Based on these observations, the youngest person is ______.
s e m
s e l a
g l a ag
a
(A) P

(B) Q

(C) R
m
(D) S
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s e
g la
a

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m .co s e m
s e g l a
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a

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Life Sciences (XL)

Q.10 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 ∠𝑂1 𝑂3 𝑂2 is 90°, 𝑟3 = _____ cm.

(A) 1
(−3 + √17 )
2

(B) 1
(3 + √17 )
2

(C) 1
(−2 + √17 )
2

(D) 1
(−3 + 2√17 )
2

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m .co s e m Chemistry (XL-P)
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Q.11 – Q.19 Carry ONE mark Each

Q.11 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

m
m .co
(A)
m .co s e m
e l a
𝑦las ag
ag
𝑥
(B)

𝑦
m
𝑥
m .co
s e
(C)
g la
a
𝑦

𝑥

(D)
m
m .co
m .co 𝑦
s e m
s e g l a
g la 𝑥 a
a

m .
.co s e m
s em l a
la
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Chemistry (XL-P)

Q.12 Upon hydrolysis of the pentapeptide Glu-Arg-Gly-Phe-Ala (represented from N- to
C- terminus) with trypsin, the peptide fragments obtained are

(A) Glu-Arg and Gly-Phe-Ala

(B) Glu-Arg-Gly-Phe and Ala

(C) Glu and Arg-Gly-Phe-Ala

(D) Glu-Arg-Gly and Phe-Ala

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m .co s e m Chemistry (XL-P)
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Q.13 The major product formed in the following reaction is

COOH conc. HNO3
30 oC

COOH
m
m .co
.co s e m
s em l a
g a
lCOOH ag
(A)
a NO 2

COOH
NO2

(B) COOH

m
COOH
m .co
NO2
s e
g la
(C) COOH a
O2N COOH

(D) COOH
NO2

m
m COOH
.co
m .co s e m
s e g l a
g la a
a

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.co s e m
s em l a
la
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Chemistry (XL-P)

Q.14 The CORRECT order of ionic character (in percentage) among the following is

(A) NaCl < HCl < HBr

(B) HCl < NaCl < HBr

(C) HCl < HBr < NaCl

(D) HBr < HCl < NaCl

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m .co s e m Chemistry (XL-P)
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Q.15 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)

m
c o m m .co
(A)
m . 3d
Sc – [Ar] 4s 2 1
s e
s e l a
g a
l – [Ar] 4s 3d ag
a
2 4
(B) Cr

(C) Mn – [Ar] 4s2 3d5

(D) Fe – [Ar] 4s2 3d6

m
.co
s em
g la buffer at physiological pH of 7.4 is/are
Q.16
a
The major component(s) of phosphate

(A) H3PO4

(B) H2PO4─
m
m
c. o(C) m.co
m
HPO42─
s e
s e g l a
g la (D) PO43─ a
a

m .
.co s e m
s em l a
la
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Chemistry (XL-P)

Q.17 The total number of distinct stereoisomers for the following compound is
_______________ (in integer).

Cl Cl

H3C CH3

Q.18 For the reaction A → products,

the half-life is independent of the initial concentration of A.

The order of the reaction is ________________ (in integer).

Q.19 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

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m .co s e m Chemistry (XL-P)
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Q.20 – Q.27 Carry TWO marks Each

Q.20 An ideal gas in an insulated container expands against zero external pressure. For
this expansion, the CORRECT statement is

m
m .co
(A) .co
Work is done by the gas
s e m
s em l a
(B) g la is done on the gas
Work ag
a
(C) Pressure of the gas remains unchanged

(D) Temperature of the gas remains unchanged

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s e
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a

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a

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Chemistry (XL-P)

Q.21 The major products P and Q obtained in the following reactions are

CN
P
Cl Acetone

CH3OH
Q
I

(A)
P= ;Q=
CN OMe

(B)
P= ;Q=
CN OMe
racemic

(C)
P= ;Q=
CN OMe
racemic

(D)
P= ;Q=
CN OMe
racemic racemic

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.co s e m

s em l a
a ag Chemistry (XL-P)

Q.22 The major product formed in the following two-step transformation is
(Note: Ts = tosyl and Ac = acetyl)

AcOH2C OAc NHAc
O
1) TsOH
m
H H N N
+
H

om
H
N N
2) H2O/ HO
. co
AcO
. c
OAc H
e m
e m l as
l as ag
ag
(A) N N

AcOH2C N N
O
H H NHAc
H H
AcO OAc

(B) N
m
.co
N
N
HOH2C
O
N
e m
H
H H
H
NH2
l as
HO OH
ag
(C) NHAc
N N
AcOH2C N N
O
H H
H H
AcO OAc
m
m
c. o (D) m.co
m
NH2
s e
s e N N
g la
g la HOH2C N N a
a H
O
H
H H
HO OH

m . c
c. o s e m
em a
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Chemistry (XL-P)

Q.23 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):

Column I Column II
Coordination Complexes Properties
E. [CuCl5]3─ I. Facial and meridonal isomerism
F. [Co(NH3)3Cl3] II. µ spin-only = 3.87 BM
G. [Co(NH3)4Cl2] III. Very faintly coloured
H. [Mn(H2O)6]2+ IV. Trigonal bipyramidal

(A) E-IV, F-III, G-II, H-I

(B) E-II, F-IV, G-I, H-III

(C) E-IV, F-I, G-II, H-III

(D) E-I, F-III, G-IV, H-II

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m .co s e m Chemistry (XL-P)
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Q.24 The CORRECT statement(s) about a competitive inhibitor of an enzyme is/are

(A) The competitive inhibitor binds to the substrate-binding site of the enzyme
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. s e
em
(B) The competitive inhibitor binds to the substrate
s g l a
l a a
(C)
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The competitive inhibitor is less effective at higher substrate concentration

(D) The competitive inhibitor is more effective at higher substrate concentration

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s e
g la
a

m
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m .co s e m
s e g l a
g la a
a

m .
.co s e m
s em l a
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Chemistry (XL-P)

Q.25 Among the following, the occupied molecular orbital(s) of carbon monoxide is/are

(A)
C O

(B)
C O

(C)

C O

(D)
C O

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m .co s e m Chemistry (XL-P)
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Q.26 The option(s) with the CORRECT order of ionisation energy is/are

(A) Al+ < Al2+ < Al3+ < Al4+
m
c o m m .co
Al < Al . < Al <Al e
(B)
em
4+ 3+ 2+ +

l as
as ag
gCll < Cl < Cl
─
a
+
(C)

(D) Cl+ < Cl < Cl─

Q.27 The 𝑝𝐻 of 10─8 M HCl (aq.) is ____________ (rounded off to two decimal
m
.co
places).

e m
Given, 𝑝𝐾𝑤 = 14.
las
ag

m
m .co
m .co s e m
s e g l a
g la a
a

m .
.co s e m
s em l a
la
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Biochemistry (XL-Q)

Q.28 – Q.35 Carry ONE mark Each

Q.28 Which one of the following immunoglobulins is known for its role in both allergy
and asthma?

(A) IgA

(B) IgM

(C) IgD

(D) IgE

Q.29 In which kind of organism, the glycerol moiety of lipid is found primarily in the
R-configuration?

(A) Bacteria

(B) Mammals

(C) Archaea

(D) Yeast

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m .co s emBiochemistry (XL-Q)
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a

Q.30 The Kennedy pathway of cellular phospholipid biosynthesis is associated
with ______ .

m
o m m .co
peroxisome.c s e
em
(A)
s l a
g la ag
(B)
a mitochondria

(C) nucleus

(D) endoplasmic reticulum

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m .co
Q.31
s e
Which of the following options show(s) the correct pairing of a complement protein
with its function?
g la
a

(A) C5a : inflammation

(B) C3b : opsonization

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m .co
.co
(C) C3a : opsonization
e m
e m l as
las (D) C5b : inflammation
ag
ag

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.co s e m
s em l a
la
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Biochemistry (XL-Q)

Q.32 Fluorescence is a result of which one or more of the following?

(A) The transition of electrons from singlet ground state to singlet transition state.

(B) The transition of electrons from lower singlet excited state to singlet ground state.

(C) The release of energy in the form of light of wavelength higher than the incident
wavelength.

(D) The release of energy in the form of light of lower wavelength than the incident
wavelength.

Q.33 A 25 amino acid α-helical protein is spanning the thickness of a mammalian cell
membrane. Using the average dimensional parameters of a typical -helix, the
thickness of the membrane will be ______ Å (rounded off to one decimal place).

Q.34 The oxidative phase of the hexose monophosphate pathway generates __________
moles of NADPH per mole of glucose 6-phosphate (answer in integer).

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m .co s emBiochemistry (XL-Q)
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Q.35 Partial double digestion of the DNA shown below with EcoRI, and XhoI will
yield ______ bands after gel electrophoresis (answer in integer).

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m .co s e m
s e l a
g l a ag
a

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m .co
s e
g la
a

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m .co
m .co s e m
s e g l a
g la a
a

m .
.co s e m
s em l a
la
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Biochemistry (XL-Q)

Q.36 – Q.46 Carry TWO marks Each

Q.36 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?

(A) Ala-Ala-Trp-Gly-Lys-Lys-Thr-Phe-Val

(B) Thr-Phe-Val-Lys-Ala-Ala-Trp-Gly-Lys

(C) Val-Lys-Ala-Ala-Trp- Gly-Lys-Thr-Phe

(D) Thr-Phe-Ala-Ala-Trp-Val-Lys-Gly-Lys

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m .co s emBiochemistry (XL-Q)
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Q.37 Which one of the following enzymes is NOT inhibited by glucose-6-phosphate?

(A) Hexokinase I
m
c o m m .co
(B)
m
Hexokinase. II s e
s e l a
g l a ag
(C)
a Hexokinase III

(D) Hexokinase IV

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s e
g la
a

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m .co s e m
s e g l a
g la a
a

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.co s e m
s em l a
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Biochemistry (XL-Q)

Q.38 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.

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

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

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

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

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m .co s emBiochemistry (XL-Q)
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a

Q.39 The correct path of transfer of electrons in the light harvesting photosystems in
vascular plants is _____________.

m
m .co
(A) .co
H2O → Photosystem II → Cyt b6f → Photosystem I → NADP+
s e m
s em l a
(B) g a
Hl O → Photosystem I → Cyt b f → Photosystem II → O ag
a 2 6 2

(C) H2O → Photosystem II → Cyt b6f → Photosystem I → O2

(D) H2O → Photosystem I → Cyt b6f → Photosystem II → NADP+

m
m .co
s e
g la
a

m
m .co
m .co s e m
s e g l a
g la a
a

m .
.co s e m
s em l a
la
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Biochemistry (XL-Q)

Q.40 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?

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

(A)

(B)

(C)

(D)

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m .co s emBiochemistry (XL-Q)
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a

Q.41 Which statement(s) is/are true about the 5′-capping of eukaryotic mRNA?

m
m .co
.co m
(A) Triphosphatase enzyme removes the γ-phosphate from the 5′-terminal nucleotide.

m s e
s e g l a
(B)
a a
A transferase links ATP to the dephosphorylated nucleotide of mRNA at its 5′-end.
l
ag
(C) Methyl transferase adds a –CH3 group to the N-7 position of the newly added
guanine base.

(D) 5′-capping happens shortly after mRNA emerges from the exit tunnel of RNA
polymerase.

m
m .co
s e
Q.42
la
Which of the following statements about pertussis toxin is/are NOT true?
g
a

(A) It causes whooping cough.

(B) It is a heterodimeric protein.

m
m .co
.co
(C) It causes ADP-ribosylation of the -subunit of Gi.
e m
e m l as
las (D) It inhibits adenylate cyclase.
ag
ag

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.co s e m
s em l a
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Biochemistry (XL-Q)

Q.43 Telomerase has which one or more of the following activities?

(A) DNA-dependent RNA polymerase

(B) Reverse transcriptase

(C) RNA-dependent DNA polymerase

(D) 5′→3′ exoribonuclease

Q.44 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).

Assuming that there are 5 × 1013 cells in the human body, and that ATP is turning
Q.45 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 ]

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m
m .co

m .co s emBiochemistry (XL-Q)
se g la
a
Q.46 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).

m
m .co
m .co s e m
s e l a
g l a ag
a

m
m .co
s e
g la
a

m
m .co
m .co s e m
s e g l a
g la a
a

m .
.co s e m
s em l a
la
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Botany (XL-R)

Q.47 – Q.54 Carry ONE mark Each

Q.47 Which one of the following plant families is characterized by the gynobasic style
of female reproductive organ?

(A) Lamiaceae

(B) Euphorbiaceae

(C) Malvaceae

(D) Poaceae

Q.48 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

(A) Dicot root

(B) Monocot root

(C) Dicot leaf

(D) Dicot stem

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m
m .co

m .co Botany (XL-R)
s e m
se g l a
a
Q.49 Correctly match the following molecules/methods in Group-I with their major uses
in Group-II.

Group-I Group-II

m
.co
(P) CRISPR-Cas9 (1) Global gene expression analysis
m
(Q)
.co
DNA Microarray (2) Molecular marker
s e m
(R)s emVir genes (3) Targeted gene editing
g l a
g l(S)a RAPD a
a (4) Agrobacterium-mediated plant
transformation

(A) P−1; Q−3; R−2; S−4
m
(B) P−3; Q−1; R−4; S−2
m .co
s e
(C) P−3; Q−1; R−2; S−4
g la
(D) P−1; Q−3; R−4; S−2
a

Q.50 Which one of the following commercial products is used as a systemic fungicide
to control plant diseases?

m
m
c. o(B)
(A) Captan
m.co
m s e
s e Phaltan
g l a
g la (C) Thiram a
a (D) Benomyl

m .
.co s e m
s em l a
la
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Botany (XL-R)

Q.51 Which one of the following terms best describes the plants that are adapted to grow
in acidic soil?

(A) Halophytes

(B) Oxylophytes

(C) Lithophytes

(D) Chasmophytes

Q.52 Which of the following plant genera is/are example(s) of partial stem parasite?

(A) Striga

(B) Orobanche

(C) Viscum

(D) Cuscuta

Q.53 Which of the following amino acids contain(s) only one chiral center?

(A) Serine

(B) Threonine

(C) Isoleucine

(D) Leucine

Q.54 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).

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m
m .co

m .co Botany (XL-R)
s e m
se g l a
a
Q.55 – Q.65 Carry TWO marks Each

Q.55 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?

m
(A)
o m
Class A only
c m .co
Class Am . class B s e
(B)
s e and
l a
(C)
g a
l B and class C
Class ag
(D)
a Class B only

Q.56 Correctly match the following molecular assemblies in Group-I with their
functions in Group-II.

m
Group-I
.co Group-II
m (1) Utilizes proton gradient for ATP
(P) Photosystem I
s e
g la synthesis

(Q) Photosystem II
a (2) Transfers electron from reduced
plastoquinone to oxidized
plastocyanin

(R) Cytochrome b6f complex (3) Drives transfer of electron from
plastocyanin to ferredoxin

(S) CF0 − CF1 complex (4) Oxidises H2O and reduces
m
.co
plastoquinone
m
m .co s e m
s e g l a
g la a
a (A) P−3; Q−4; R−1; S−2

(B) P−3; Q−4; R−2; S−1

(C) P−2; Q−4; R−3; S−1

(D) P−4; Q−1; R−2; S−3

m .
.co s e m
s em l a
la
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Botany (XL-R)

Q.57 Correctly match the following secondary metabolites in Group-I with their
chemical classes in Group-II.

Group-I Group-II

(P) Codeine (1) Flavones

(Q) Podophyllotoxin (2) Alkaloids

(R) Resveratrol (3) Lignans

(S) Linamarin (4) Monoterpenes

(T) Limonene (5) Cyanogenic glycosides

(6) Stilbenes

(A) P−1; Q−2; R−6; S−5; T−4

(B) P−2; Q−5; R−6; S−3; T−4

(C) P−2; Q−3; R−5; S−4; T−1

(D) P−2; Q−3; R−6; S−5; T−4

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m
m .co

m .co Botany (XL-R)
s e m
se g l a
a
Q.58 Correctly match the following plant diseases in Group-I with their causal
organisms in Group-II.

Group-I Group-II

m
.co
(P) Red rot of sugarcane (1) Albugo candida
m
(Q)
.co
Tikka disease of groundnut (2) Cercospora personata
s e m
s em l a
ag
(R) Late blight of potato (3)
g a
l(S) White rust of mustard
Plasmodiophora brassicae

a (4) Phytophthora infestans

(5) Colletotrichum falcatum

m
(A) P−1; Q−2; R−4; S−3
m .co
(B) P−5; Q−1; R−4; S−2
s e
g la
(C) P−5; Q−2; R−4; S−1 a
(D) P−5; Q−3; R−1; S−2

m
m .co
m .co s e m
s e g l a
g la a
a

m .
.co s e m
s em l a
la
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Botany (XL-R)

Q.59 Correctly match the following plant species in Group-I with their main
economically important products in Group-II.

Group-I Group-II

(P) Gossypium arboreum (1) Rubber

(Q) Dalbergia sissoo (2) Spices

(R) Hevea brasiliensis (3) Fibre

(S) Pelargonium graveolens (4) Timber

(5) Essential oil

(A) P−3; Q−4; R−1; S−5

(B) P−3; Q−4; R−1; S−2

(C) P−2; Q−4; R−1; S−3

(D) P−3; Q−1; R−2; S−5

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m
m .co

m .co Botany (XL-R)
s e m
se g l a
a
Q.60 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
m
m
(iii) Double mutant of gain-of-function of X and loss-of-function of Y
.co
.co
m of the following genetic pathways best describes these observations? las e m
Whicheone
l as ag
ag
(A) X suppresses Y and Y promotes root development

(B) X promotes Y and Y promotes root development

(C) X suppresses Y and Y supresses root development

(D) X promotes Y and Y supresses root development
m
m .co
Q.61
s e
Which of the following combinations of photosynthetic carbon cycle in plants,
la
and its matched biochemical reaction is/are correct?
g
a
(A) C3 pathway : Ribulose 1,5-bisphosphate + CO2 + H2O → 2 3-phosphoglycerate

(B) C2 pathway : 2 Glycolate + 2 O2 → 2 glyoxylate + 2 H2O2

(C) C4 pathway : 2 2-Phosphoglycolate + 2 H2O → 2 glycolate + 2 Pi

(D) CAM pathway : Phosphoenolpyruvate + HCO3− → oxaloacetate + Pi m
m .co
m .co s e m
s e g l a
g la a
a

m .
.co s e m
s em l a
la
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Botany (XL-R)

Q.62 Choose the correct combination(s) of alkaloid, source plant, and their main
commercial use.

(A) Vincristine – Catharanthus roseus – anticancer drug

(B) Scopolamine – Hyoscyamus niger – anticholinergic drug

(C) Cocaine – Conium maculatum – antimalarial drug

(D) Pilocarpine – Eschscholzia californica – antidepressant drug

Q.63 Which of the following statements is/are correct about plant movement?

(A) Diaheliotropic refers to orienting the leaves perpendicular to the rays of the sun to
maximize light interception.

(B) Paraheliotropic refers to orienting the leaves parallel to the rays of the sun to
minimize light interception.

(C) Diaheliotropic refers to orienting the leaves parallel to the rays of the sun to
minimize light interception.

(D) Paraheliotropic refers to orienting the leaves perpendicular to the rays of the sun to
maximize light interception.

Q.64 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).

Q.65 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 (kcat) 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 (Km) would be___________ × 10−6 M (in integer).

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m
m .co

m .co s emMicrobiology (XL-S)
se g la
a
Q.66 – Q.73 Carry ONE mark Each

Q.66 Which one of the following statements about microbiological stains is CORRECT?

m
m .co
.co m
(A) Acid-fast stain is a simple stain.

m s e
s e l a
(B)
g la
Gram stain is used to visualize endospores.
ag
a
(C) Methylene blue is an acidic dye.

(D) India ink is used to visualize capsules.

m
Q.67 .co
The genome of which one of the following viruses encodes reverse transcriptase?
m
s e
g la
a
(A) Human immunodeficiency virus

(B) Influenza virus

(C) Poliovirus
m
m
c. o(D) m.co
m
Rabies virus
s e
s e g l a
g la a
a

m .
.co s e m
s em l a
la
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Microbiology (XL-S)

Q.68 Protoplasts can be generated from

(A) Streptococcus pneumoniae.

(B) Brucella abortus.

(C) Pasteurella multocida.

(D) Shigella flexneri.

Q.69 Which one of the following molecules is the master regulator of the planktonic-
surface transition in Pseudomonas aeruginosa during biofilm formation?

(A) Cyclic thiolactone

(B) Cyclic dimeric guanosine monophosphate

(C) Cyclic triadenylate

(D) Cyclohexamide

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m
m .co

m .co s emMicrobiology (XL-S)
se g la
a
Q.70 Which one of the following is a protozoal disease?

(A) Cholera
m
o m m .co
Gonorrhea.c e
(B)
em l as
la s ag
(C)
agKala-azar

(D) Syphilis

Q.71 Which one of the following drugs is a viral protease inhibitor?
m
m .co
s e
g la
(A) Acyclovir a
(B) Nevirapine

(C) Ritonavir

m
.co
(D) Zidovudine
m
m .co s e m
s e g l a
g la a
a

m .
.co s e m
s em l a
la
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Microbiology (XL-S)

Q.72 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)

Q.73 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)

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m
m .co

m .co s emMicrobiology (XL-S)
se g la
a
Q.74 – Q.84 Carry TWO marks Each

Q.74 Which one of the following options correctly matches the microbial names in
Column I with their corresponding sources of epithet in Column II?

Column I Column II
m
m .co
.co
(P) Klebsiella pneumoniae (i) causes stupor in mice
s e m
s em l a
g la Penicillium chrysogenum ag
a (Q) (ii) forms pus

(R) Salmonella typhimurium (iii) the disease it causes

(S) Streptococcus pyogenes (iv) produces a yellow pigment

m
m .co
s e
g la
(A) P-i; Q-ii; R-iii; S-iv a
(B) Q-i; R-ii; S-iii; P-iv

(C) R-i; S-ii; P-iii; Q-iv

m
.co
(D) S-i; Q-ii; P-iii; R-iv
m
m .co s e m
s e g l a
g la a
a

m .
.co s e m
s em l a
la
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Microbiology (XL-S)

Q.75 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.

(A) Both [a] and [r] are true and [r] is the correct reason of [a].

(B) Both [a] and [r] are true but [r] is not the correct reason of [a].

(C) Both [a] and [r] are false.

(D) [a] is true but [r] is false.

Q.76 When tryptophan level is low in Escherichia coli, the expression of tryptophan
biosynthesis genes is turned on through an antiterminator stem-loop formation
between

(A) regions 1 and 2 of the leader sequence (trpL) of mRNA.

(B) regions 2 and 3 of the leader sequence (trpL) of mRNA.

(C) regions 2 and 4 of the leader sequence (trpL) of mRNA.

(D) regions 3 and 4 of the leader sequence (trpL) of mRNA.

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m
m .co

m .co s emMicrobiology (XL-S)
se g la
a
Q.77 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?

m
m .co
m .co s e m
s e l a
g l a ag
a

m
(A) Mutant-1
m .co
s e
g la
(B) Mutant-2
a
(C) Mutant-3

(D) Mutant-4

m
m .co
m .co s e m
s e g l a
g la a
a

m .
.co s e m
s em l a
la
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Microbiology (XL-S)

Q.78 Which one of the following leukocytes is the most abundant in a healthy human?

(A) Basophils

(B) Eosinophils

(C) Monocytes

(D) Neutrophils

Q.79 DNA amplification in the polymerase chain reaction is

(A) linear.

(B) parabolic.

(C) sigmoidal.

(D) exponential.

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m
m .co

m .co s emMicrobiology (XL-S)
se g la
a
Q.80 In bacteriophage lambda (λ) life cycle, binding of Cro protein to cI gene operator
region

m
(A)
m
activates cI gene expression.
.co
.co s e m
(B)
s em
directs towards the lysogenic state. l a
g la ag
(C) a directs towards the lytic cycle.

(D) prevents cI gene expression.

m
.co
Q.81 Which of the following is/are ring(s) of bacterial flagellum?

e m
las
ag
(A) C ring

(B) L ring

(C) P ring

m
m .co
.co
(D) Z ring
e m
e m l as
las ag
ag

m .
.co s e m
s em l a
la
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Microbiology (XL-S)

Q.82 Which of the following bacteria is/are uncultivable?

(A) Borrelia burgdorferi

(B) Leptospira interrogans

(C) Mycobacterium leprae

(D) Treponema pallidum

Q.83 Which of the following antibiotic(s) inhibit(s) bacterial protein synthesis?

(A) Erythromycin

(B) Tetracycline

(C) Bacitracin

(D) Vancomycin

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m
m .co

m .co s emMicrobiology (XL-S)
se g la
a
Q.84 Scientist(s) who contributed in disproving the theory of spontaneous generation
is/are

m
(A) Ferdinand Cohn.
m .co
.co s e m
(B)
s em
John Needham. l a
g la ag
(C) a John Tyndall.

(D) Louis Pasteur.

m
m .co
s e
g la
a

m
m .co
m .co s e m
s e g l a
g la a
a

m .
.co s e m
s em l a
la
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Zoology (XL-T)

Q.85 – Q.92 Carry ONE mark Each

Q.85 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?

(A) Competition-colonisation trade-off

(B) Competitive exclusion principle

(C) Interference competition

(D) Trophic cascade

Q.86 Immunoglobulins are classified into the following isotypes: IgG, IgM, IgA, IgD,
IgE. What region of the immunoglobulin is used to determine this classification?

(A) The constant region of the heavy chain only

(B) The constant region of the light chain only

(C) The variable region of both the heavy and light chains

(D) The constant region of both the heavy and light chains

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m
m .co

.co s e m
em
Zoology (XL-T)

s g l a
a
Q.87 Correctly match the cell types in Column I to their primary function in Column II.

Column I Column II

P) Melanocyte 1) Muscle contraction

m
.co
Q) Myocyte 2) Pigment production
m
c. o R) Granulosa 3) Antibody production
s e m
e m l a
l as S) B-cell 4) Estrogen secretion
ag
ag

(A) P – 1; Q – 3; R – 2; S – 4

m
.co
(B) P – 2; Q – 1; R – 4; S – 3

e m
(C) P – 1; Q – 2; R – 3; S – 4
las
ag
(D) P – 2; Q – 3; R – 4; S – 1

m
m .co
m .co s e m
s e g l a
g la a
a

m .
.co s e m
s em l a
la
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Zoology (XL-T)

Q.88 Which one of the following groups includes at least one animal that is
NOT an arthropod?

(A) Group 1: crustaceans, scorpions, mites, insects

(B) Group 2: trilobites, horseshoe crabs, centipedes

(C) Group 3: millipedes, horseshoe crabs, sponges, earthworms

(D) Group 4: butterflies, moths, beetles

Q.89 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?

(A) Females obtain more resources by mating with multiple males

(B) Multiple mating increases the genetic variation among the offspring

(C) Multiple mating increases the probability of fertilization

(D) Multiple mating increases relatedness among the offspring

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m
m .co

.co s e m
em
Zoology (XL-T)

s g l a
a
Q.90 Which one or more of the following terms describe(s) Toxoplasma gondii?

(A) Virus
m
o m m .co
Parasite .c e
(B)
em l as
la s ag
(C)
agBacteria

(D) Fungus

Q.91 Which of the following statements is/are NOT correct about the technique used in
m
.co
molecular biology?

e m
las
ag
(A) Southern blotting is used to detect specific DNA sequences

(B) Northern blotting is used to detect RNA expression levels

(C) Western blotting is used to detect proteins using antibodies

m
m .co
.co
(D) ELISA is used to detect specific DNA sequences directly without antibodies
e m
e m l as
las ag
ag
Q.92 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).

m .
.co s e m
s em l a
la
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