# XL Life Science- 2013 GATE Paper (Practice Test)

## 125 Questions MCQ Test GATE Past Year Papers for Practice (All Branches) | XL Life Science- 2013 GATE Paper (Practice Test)

Description
Attempt XL Life Science- 2013 GATE Paper (Practice Test) | 125 questions in 180 minutes | Mock test for GATE preparation | Free important questions MCQ to study GATE Past Year Papers for Practice (All Branches) for GATE Exam | Download free PDF with solutions
QUESTION: 1

Solution:
QUESTION: 2

Solution:
QUESTION: 3

### Mahatama Gandhi was known for his humility as

Solution:
QUESTION: 4 Which of the above underlined parts of the sentence is not appropriate?

Solution:
QUESTION: 5

Select the pair that best expresses a relationship similar to that expressed in the
pair:

water: pipe::

Solution:
QUESTION: 6

Q. No. 6 – 10 Carry Two Marks Each

Q.

Velocity of an object fired directly in upward direction is given by V = 80 − 32 t,
where t (time) is in seconds. When will the velocity be between 32 m/sec and 64
m/sec?

Solution:
QUESTION: 7

In a factory, two machines M1 and M2 manufacture 60% and 40% of the autocomponents respectively. Out of the total production, 2% of M1 and 3% of M2 are found to be defective. If a randomly drawn autocomponent from the combined lot is found defective, what is the probability that it was manufactured
by M2?

Solution:
QUESTION: 8

Following table gives data on tourists from different countries visiting India in the
year 2011. Which two countries contributed to the one third of the total number of tourists who visited India in
2011?

Solution:
QUESTION: 9

If |−2X + 9| = 3 then the possible value of |−X| − X2 would be:

Solution:
QUESTION: 10

All professors are researchers
Some scientists are professors
Which of the given conclusions is logically valid and is inferred from the above
arguments:

Solution:
QUESTION: 11

Q. 11 – Q. 15 carry one mark each

Q.

N(CH3)3 and N(SiH3)are congeners, but around N-atom the former has pyramidal geometry
whereas the latter is nearly planar. The bonding responsible for planarity of N(SiH3)is

Solution:
QUESTION: 12

The type of electronic transition responsible for the yellow colour of K2CrO4 is

Solution:
QUESTION: 13

The given equation where H, T and Cp are the enthalpy, temperature and heat capacity at constant pressure,
respectively, is called

Solution:
*Answer can only contain numeric values
QUESTION: 14

Q. 14 - Q. 15 are questions with numerical answer.

Q.

The number of 2-center-2-electron bonds in anhydrous AlCl3 is ___________

Solution:
*Answer can only contain numeric values
QUESTION: 15

When dissolved in water, the number of H+ ions released from a molecule of H3BOis _________

Solution:
QUESTION: 16

Q. 16 - Q. 25 carry two marks each.

Q.

In NaCl crystal, the arrangement and coordination number of the ions are

Solution:
QUESTION: 17

The solubility product In a 0.02 M solution of Ca(NO3)2, the solubility of Ca3(PO4)2 (in units of M) is

Solution:
QUESTION: 18

Identify the CORRECT product in the following reaction Solution:
QUESTION: 19

The major product obtained in the following reaction is Solution:
*Answer can only contain numeric values
QUESTION: 20

Q. 20- Q. 21 are questions with numerical answer.

Q.

Iodine forms an anionic species Q in aqueous solution of iodide(I-). The number of lone pair(s) of
electrons on the central atom of Q is __________

(Important : you should answer only the numeric value)

Solution:
*Answer can only contain numeric values
QUESTION: 21

The rate of a chemical reaction is tripled when the temperature of the reaction is increased from 298
K to 308 K. The activation energy (in kcal mol-1 K-1, up to one decimal place) for the reaction
is(Given R = 1.987cal mol-1 K-1) _____________

Solution:
QUESTION: 22

Common Data for Questions 22 and 23:

Consider the following SN2 reaction of optically pure 1-chloro-3-ethylcyclopentane (X). Q.

The structure of Y in the above reaction is

Solution:
QUESTION: 23

Consider the following SN2 reaction of optically pure 1-chloro-3-ethylcyclopentane (X). Q.

The absolute configuration of1-chloro-3-ethylcyclopentane (X) shown above is

Solution:
QUESTION: 24

The molar conductance at infinite dilution of sodium acetate, sodium sulfate and sulfuric acid solutions are 91.0 ×10-4, 259.8×10-4 and 859.3×10-4S m2 mol-1, respectively.

Q.

The molar conductance at infinite dilution (in S m2 mol-1)of acetic acid is

Solution:
QUESTION: 25

The molar conductance at infinite dilution of sodium acetate, sodium sulfate and sulfuric acid solutions are 91.0 ×10-4, 259.8×10-4 and 859.3×10-4S m2 mol-1, respectively.

Q.

If the molar conductance of an acetic acid solution is15.2 ×10-4Sm2 mol-1,then the percentage (%)
dissociation of acetic acid in the solution will be

Solution:
QUESTION: 26

Q. 1 – Q. 10 carry one mark each.

Q.

Which one of the following statements is TRUE when a cell is kept in a hypotonic solution?

Solution:
QUESTION: 27

Which one of the following amino acids has a higher propensity for cis peptide bond
formation?

Solution:
QUESTION: 28

The length of an α-helix composed of 36 amino acid residues is

Solution:
QUESTION: 29

The order n for a given substrate concentration in an enzyme catalyzed reaction following Michaelis-Menten kinetics, is

Solution:
QUESTION: 30

Which one of the following amino acid residues is specifically recognised by chymotrypsin
during peptide bond cleavage?

Solution:
QUESTION: 31

The terminal electron acceptor during mitochondrial respiration is

Solution:
QUESTION: 32

During the biosynthesis of urea in the urea cycle, the two nitrogen atoms are derived from

Solution:
QUESTION: 33

An enzyme has two binding sites for an inhibitor molecule. When the inhibitor binds to the
first site, the dissociation constant of the inhibitor for the second site increases, leading to
negative co-operativity. The Hill coefficient for such an inhibitor is

Solution:
QUESTION: 34

An oligonucleotide was sequenced by the dideoxy method of Sanger and the following The sequence of the oligonucleotide is

Solution:
QUESTION: 35

In different types of tissue transplantations, the rate of graft rejection in decreasing order is

Solution:
QUESTION: 36

Q. 36 - Q. 45 carry two marks each.

Q.

You have prepared 1.0 liter of 0.5 M acetate buffer (pH=5.0). The dissociation constant of
acetic acid is 1.7×10-5 M. What would be the acetate ion concentration in the buffer?

Solution:
QUESTION: 37

The following figures show the plot of reaction rate versus substrate concentration (mM)
for an enzyme catalyzed reaction in the presence and absence of an inhibitor. Match the
possible reaction types with the plots.

(P) Competitive inhibition

(Q) Substrate inhibition
(R) Michaelis-Menten

(S) Non-competitive inhibition  Solution:
QUESTION: 38

Arrange the following in the decreasing order of their permeability coefficients across a
lipid bilayer membrane.

(i) Urea
(ii) Glucose
(iii) H2O
(iv) Na+
(v) Tryptophan

Solution:
QUESTION: 39

Arrange the following in the increasing order of amount of ATP generated by metabolism
of one molecule of the following compounds.
(i) Anaerobic catabolism of starch with 300 glucose units
(ii) Aerobic catabolism of glucose
(iii) Aerobic catabolism of acetate
(iv) Aerobic catabolism of palmitate

Solution:
QUESTION: 40

Match the following enzymes with their regulatory mechanism Solution:
QUESTION: 41

A researcher wants to clone 3 DNA fragments of sizes 1.1 Mb, 0.097 Mb and 0.045 Mb.
The choice of the vectors for cloning each of the fragments are

Solution:
QUESTION: 42

Which of the four restriction enzymes given below cut the following DNA sequence?

5’-CCGATATCTCGAGGGC-3’

(P) BamH1 (3’-CCTAG^G-5’)
(Q) XhoI (3’-GAGCT^C-5’)
(R) EcoRI (3’-CTTAA^G-5’)
(S) EcoRV (3’-CTA^TAG-5’)

Solution:
QUESTION: 43

You have expressed the following protein that has an isoelectric point of 6.0. The best
order of protein purification methodologies to obtain a pure protein is? Solution:
QUESTION: 44

An enzyme of 40 kDa is added to a substrate solution in a molar ratio of 1:3. The
concentration of the enzyme in the mixture is 12 mg/ml. What would be the corresponding
substrate concentration?

Solution:
QUESTION: 45

A patient suffering from pneumonia and tuberculosis was found to have very low CD4+ T
cells. In all probability the PRIMARY causative infectious agent belongs to

Solution:
QUESTION: 46

Q. 46 – Q. 55 carry one mark each.

Q.

Bast fibres are present in

Solution:
QUESTION: 47

During cellular respiratory process, pyruvate must be oxidized to acetyl CoA and CO2 before it
enters the citric acid cycle. The corresponding simplified equation is

This oxidation reaction occurs in mitochondria and is carried out in presence of the enzyme

Solution:
QUESTION: 48

Which one of the following statements having the terms - gene, chromosome and genome is
CORRECT?

Solution:
QUESTION: 49

The aflatoxin found in post-harvested grains is injurious to health due to

Solution:
QUESTION: 50

Identify the event that exclusively occurs in meiotic cell division

Solution:
QUESTION: 51

In the symbiotic nitrogen fixation process, Leghemoglobin present in the nodule helps in fixing
nitrogen in presence of the enzyme

Solution:
QUESTION: 52

Considering environment and ecosystem, identify the INCORRECT statement

Solution:
QUESTION: 53

The two enzymes commonly used for isolation of protoplasts from plants are

Solution:
QUESTION: 54

For successful transfer of a foreign gene from the engineered Ti-plasmid to the plant genome, few
cis-acting DNA elements and trans-acting protein factors are very much essential. Select the
CORRECT combination from the following

Solution:
QUESTION: 55

In naturally occurring cytoplasmic male sterility, the molecular determinant is located in

Solution:
QUESTION: 56

Q. 56 - Q. 65 carry two marks each.

Q.

Identify the floral formula with the family and the corresponding plant species  Solution:
QUESTION: 57

A plant of genotype GGHH is crossed with another plant of the genotype gghh. If the F1 is test
crossed, what percentage (%) of the test cross progeny will have the genotype gghh when the two
genes are - (P) unlinked, (Q) completely linked with no crossing over, (R) 10 m.u. (genetic map
unit) apart, (S) 24 m.u. apart?

Solution:
QUESTION: 58

Which two of the following are the CORRECT statements ?

P. Nondisjunction in the parental meiosis is not essential to produce diploid organisms
Q. Nondisjunction in the parental meiosis is essential to produce aneuploid organisms
R. Nondisjunction in the parental meiosis is essential to produce hexaploid organisms
S. Nondisjunction in the parental meiosis is essential to produce tetraploid organisms

Solution:
QUESTION: 59

Identify the correct matching by taking one item from each column Solution:
QUESTION: 60

Which two of the following are the INCORRECT statements ?

P. All plants fix CO2 by the action of ribulose biphosphate carboxylase. The reaction occurs in the
bundle sheath of C4 plants
Q. All plants fix CO2 by the action of ribulose biphosphate carboxylase. The reaction occurs in the
mesophyll cells of C4 plants
R. Phosphoenol pyruvate + CO→ Oxaloacetate + Pi, catalyzed by the enzyme phosphoenol
pyruvate carbxylase occurs in the mesophyll cells of C4 plants
S. Phosphoenol pyruvate + CO2 → Oxaloacetate + Pi, catalyzed by the enzyme phosphoenol
pyruvate dehydrogenase occurs in the mesophyll cells of C4 plants

Solution:
QUESTION: 61

Select the CORRECT set comprising only the synthetic analogues of auxin and cytokinin

Solution:
QUESTION: 62

Which two of the following are the INCORRECT statements ?
P. In monocotyledonous stems with closed vascular bundle, secondary growth takes place without
any cambium
Q. In dicotyledonous stems hypodermis is collenchymatous
R. Mobilization of storage reserves takes place during post-germination of embryo
S. Osborne’s classification of seed storage proteins is based upon solubility in n-hexane

Solution:
QUESTION: 63

Identify two CORRECT characteristic features of (P) Autogamy and (Q) Allogamy from the
following statements
1. Plant species usually does not depend on external agents
2. Plant species usually depends on external agents
3. Plant species normally produces progeny that are healthier and better adapted in nature
4. Plant species normally produces weaker progeny in several generations

Solution:
QUESTION: 64

Identify the correct matching by taking one item from each column Solution:
QUESTION: 65

Identify two CORRECT statements from the following which are related to the ion transportation
in the root system of plant
P. The proton pumps and H+-pyrophosphatase appear to work in anti-parallel with the vacuolar
ATPase to create a proton gradient across the tonoplast
Q. Calcium is one of the important ion whose concentration is strongly regulated by the
concentration of apoplastic spaces in the millimolar level
R. Solute move through both apoplast and symplast, and xylem parenchyma cells participate in
S. The limitation of Nerst equation for relating the membrane potential to the distribution of ion at
equilibrium is that it cannot distinguish between active and passive transport

Solution:
QUESTION: 66

Q. 66 – Q. 75 carry one mark each.

Q.

In 1976, Tonegawa’s experiment gave clue about gene rearrangement during differentiation of Bcells.
The two different types of cells used in this experiment were

Solution:
QUESTION: 67

To which one of the following groups, the antibiotics kanamycin, streptomycin and gentamicin
belong

Solution:
QUESTION: 68

Shine Dalgarno’s sequence present in mRNA binds to

Solution:
QUESTION: 69

Which one of the following transport mechanism is NOT employed by prokaryotes?

Solution:
QUESTION: 70

The most common indicator organism of faecal pollution in water is

Solution:
QUESTION: 71

The theoretical maximum number of ATP molecules produced from aerobic oxidation of glucose
by eukaryotic cells is

Solution:
QUESTION: 72

Which one of the following DO NOT use water as an electron source during photosynthesis?

Solution:
QUESTION: 73

If the radius of a spherical coccus is 0.8 μm, the value of surface area/ volume  in μm-1 will be

Solution:
QUESTION: 74

The enzyme that catalyzes the reduction of nitrogen to ammonia is

Solution:
QUESTION: 75

Chemostat is a continuous culture system in which sterile medium is fed into the culture vessel at
the same rate as the spent medium is removed. If in a chemostat culture, the flow rate is 30 ml h-1
and volume of the medium inside the vessel is 100 ml, the dilution rate in h-1 is

Solution:
QUESTION: 76

Q. 76 - Q. 85 carry two marks each.

Q.

In an experiment the structural genes lacZYAof lac operon were found to be constitutively
expressed. The following explanations were given for the constitutive expression
(P) absence of a functional repressor due to mutation in the repressor gene lacI
(Q) mutation in the operator that can no longer bind the repressor
(R) mutation in the lacAgene
Which of the following is CORRECT

Solution:
QUESTION: 77

Which one of the following is TRUE about siderophores in bacteria?

Solution:
QUESTION: 78

In a population containing fast and slow growing bacteria, the slow growing bacteria can be
enriched by supplementing the medium with

Solution:
QUESTION: 79

When the supply of tryptophan is plentiful, the tryptophan operon is repressed because the

Solution:
QUESTION: 80

Match the scientists in Group I with their contributions in microbiology in Group II Solution:
QUESTION: 81

Match the infectious agents in Group I with the associated diseases in Group II (Note: correct answer will be updated soon, Temporary marked A)

Solution:
QUESTION: 82

Match the microscopes in Group I with their working principles in Group II Solution:
QUESTION: 83

In a phenol coefficient test for determining the efficacy of a disinfectant X, the maximum effective
dilution for X and phenol was found to be 1/450 and 1/90, respectively. Calculate the phenol
coefficient for X.

Solution:
QUESTION: 84

How many electrons are accepted when sulfate acts as the terminal electron acceptor in bacteria
such as Desulfovibrio?

Solution:
QUESTION: 85

A bacterial population increases from 103 cells to 109 cells in 10 h. Calculate the number of
generations per hour.

Solution:
QUESTION: 86

Q. 86 – Q. 95 carry one mark each.

Q.

Which one of the following provides the strongest support for the theory of “descent with
modification”?

Solution:
QUESTION: 87

Which one of the following is an example of sympatric speciation?

(Note: correct answer will be updated soon, Temporary marked A)

Solution:
QUESTION: 88

The primary difference between glycogen and cellulose is in the

Solution:
QUESTION: 89

Control mechanisms operate at any of the several steps involved in gene expression. Which one of
the following is the key mode of regulation during the cell cycle?

Solution:
QUESTION: 90

Testicular feminization syndrome is a genetic condition wherein an individual with a XY genotype
will have an external female-like phenotype. This is caused by

Solution:
QUESTION: 91

Which one of the following defects do you expect to see if you were able to specifically block
apoptosis in the developing limb bud of a frog embryo?

Solution:
QUESTION: 92

The formation of antigen-antibody complex helps in disposing antigen through the following
pathways EXCEPT:

Solution:
QUESTION: 93

The term “ecological succession” refers to:

Solution:
QUESTION: 94

Which one of the following options provide example for the term “habituation” in behavioral
ecology?

Solution:
QUESTION: 95

Among the following cell structure-function pairs, identify the correctly paired one

Solution:
QUESTION: 96

Q. 11 - Q. 20 carry two marks each

Q.

Which of the following most accurately states the goal of systematics?

Solution:
QUESTION: 97

Among the following options, choose the one that is probably a cause of rapid diversification of
animal groups during the Cambrian explosion.

Solution:
QUESTION: 98

A newly discovered, recessively-inherited disease-susceptibility trait (DS) is observed only in
cotton plants with white flowers, although the flower colour (R) and DS are independently
inherited. In a breeding programme, one variety that is homozygous for the absence of DS, but
heterozygous for R was mated to another having white flowers but heterozygous for DS. What is
the probability that a given plant among the cross progeny will be susceptible to the disease?

Solution:
QUESTION: 99

In a new species of moth, the genes for body colour (black, B, is dominant over grey, b), wing size
(normal wing, W, is dominant over vestigial, w) and eye colour (red, R, is dominant over white, r)
are linked. In this species, only one cross-over event has been observed between any two
homologous chromosomes during meiosis. In a cross between BB; ww and bb; WW, 5 % of the
progeny were black with normal wings. In a separate cross between RR; WW and rr; ww, 15 % of
the progeny were red-eyed with vestigial wings. In a third cross between BB; rr and bb; RR, 10 %
of the progeny were black-coloured with red eyes. Which among the following is the correct order
of these three genetic loci?

(Note: correct answer will be updated soon, Temporary marked A)

Solution:
QUESTION: 100

In vertebrates, the variations in the structure and function of nephrons are directly linked to the
osmoregulatory requirements of the organisms depending on the habitats they live in. From the
options given below, identify the correct combination that truly represents the adaptation seen in
desert mammals:
i. Long loops of Henle
ii. Short loop of Henle
iii. Hyperosmotic urine
iv. Large volume of urine
v. Removal of nitrogen as uric acid

Solution:
QUESTION: 101

In Drosophila, mutations in homeotic genes result in which one of the following developmental
defects?

Solution:
QUESTION: 102

Retroviruses, like the influenza virus, escape the detection of pre-existing antibodies in the host by
generating surface antigen variants. They do so:

Solution:
QUESTION: 103

The relative number of individuals in each age group is an important demographic factor for the
study of future growth trends, and this is normally depicted in the form of an age-structure pyramid.
Based on your understanding on population dynamics, match the following distribution properties
of age structure (Group 1) with the individual forecast given (Group 2):
Group 1
I). Uniform age distribution in the pyramid
II). Distribution skewed towards younger age groups
III). Distribution skewed towards older age groups
IV). Reduction in the number of males in the middle age group
Group 2
i). Emigration in the recent past and the possible increase in the older age groups in the near
future.
ii). Likely to be a stable population
iii). Possible unemployment in the near future
iv). Increased government expenditure on medical needs and social security related issues in the
near future

Solution:
QUESTION: 104

Like any other trait, animal behavior also evolves by natural selection. Which one of the following
examples is NOT true with regard to the evolution of behavior by natural selection?

Solution:
QUESTION: 105

Among the following molecular process-biological effect pairs, identify the mismatched pair.

Solution:
QUESTION: 106

Q. 106 – Q. 115 carry one mark each.

Q.

Kawashiorkor disease is caused due to the deficiency of

Solution:
QUESTION: 107

Which of the following statements is TRUE in case of oxidative rancidity of vegetable oils and
fats?

(Note: correct answer will be updated soon, Temporary marked A)

Solution:
QUESTION: 108

The food borne disease, Q fever is caused by the organism

Solution:
QUESTION: 109

The primary bacterial spoilage of poultry meat at low temperature, with characteristic sliminess at
outer surface, is caused by

Solution:
QUESTION: 110

The weight gain (in gram) per gram protein consumed is called

Solution:
QUESTION: 111

Which of the following carbohydrates is NOT classified as dietary fibre?

Solution:
QUESTION: 112

In the extruder barrel, the compression is achieved by back pressure created by the die and by

Solution:
QUESTION: 113

The brown colour of bread crust during baking is due to Maillard reaction between

Solution:
QUESTION: 114

Blanching influences vegetable tissues in terms of

Solution:
QUESTION: 115

When garlic is cut or processed, the crushed garlic odour is due to the formation of

Solution:
QUESTION: 116

Q. 11 - Q. 20 carry two marks each.

Q.

Match the toxicants of plant foods in Group I with their main plant source given in Group II. Solution:
QUESTION: 117

Match the products in Group I with the enzymes used for their preparation given in Group II. Solution:
QUESTION: 118

Match the food items in Group I with the type of colloidal dispersion given in Group II. (Note: correct answer will be updated soon, Temporary marked A)

Solution:
QUESTION: 119

[a] Assertion: In the presence of sucrose, the temperature and time for gelatinization of starch
increases.
[r] Reason: Sucrose, due to its hygroscopic nature, competes with starch for water needed for
gelatinization.

Solution:
QUESTION: 120

Thermal death of viable spores of Bacillus subtilis in a food sample follows a first order kinetics
with a specific death rate constant of 0.23 min-1 at 100°C. The time (in minutes) required to kill
99% of spores in the food sample at 100°C will be

Solution:
QUESTION: 121

How much skim milk (in kg) containing 0.1% fat should be added to 500 kg of cream containing
50% fat to produce standardized cream containing 36% fat?

Solution:
QUESTION: 122

Which of the following statements is NOT CORRECT in relation to muscle proteins ?

Solution:
QUESTION: 123

A cold storage plant is used for storing 50 tonnes of apples in perforated plastic crates. During the
storage, apples are cooled down from 28°C to storage temperature of 2°C. (Specific heat of the
apple = 0.874 kCal kg-1 °C-1). If the required cooling is attained in 16 hours, the refrigeration plant
capacity (in Tons) is

Solution:
QUESTION: 124

An actively growing culture of Acetobacter aceti is added to the vigorously aerated fermented fruit
juice medium containing 10 g l-1 ethanol to produce vinegar. After some time, the ethanol
concentration in the medium is 0.8 g l-1 and acetic acid produced is 8.4 g l-1. What is the conversion
efficiency of the process with respect to theoretical yield?

Solution:
QUESTION: 125

An enzyme catalyzed reaction (following Michaelis-Menten kinetics) exhibits maximum reaction
velocity (Vm) of 75 nmol l-1 min-1. The enzyme at a substrate concentration of 1.0x10-4 M shows the
initial reaction velocity of 60 nmol l-1 min-1. The Km value of the enzyme in molar concentration
(M) is

Solution: Use Code STAYHOME200 and get INR 200 additional OFF Use Coupon Code