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

Which of the above underlined parts of the sentence is not appropriate?

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

water: pipe::

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?

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?

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?

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

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

Q. 11 – Q. 15 carry one mark each

Q.

N(CH₃)₃ and N(SiH₃)₃ 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)₃ is

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

The given equation

where H, T and C_p are the enthalpy, temperature and heat capacity at constant pressure,
respectively, is called

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

Q.

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

When dissolved in water, the number of H⁺ ions released from a molecule of H³BO³ is _________

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

Q.

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

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

Identify the CORRECT product in the following reaction

The major product obtained in the following reaction is

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)

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) _____________

Common Data for Questions 22 and 23:

Consider the following S_N2 reaction of optically pure 1-chloro-3-ethylcyclopentane (X).

Q.

The structure of Y in the above reaction is

Consider the following S_N2 reaction of optically pure 1-chloro-3-ethylcyclopentane (X).

Q.

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

Statement for Linked Answer Questions 24 and 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.

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

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

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?

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

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

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

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

The terminal electron acceptor during mitochondrial respiration is

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

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

An oligonucleotide was sequenced by the dideoxy method of Sanger and the following
autoradiogram was obtained

The sequence of the oligonucleotide is

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

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?

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

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

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

Match the following enzymes with their regulatory mechanism

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

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’)

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?

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?

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

Q. 46 – Q. 55 carry one mark each.

Q.

Bast fibres are present in

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

Pyruvate + NAD⁺ + CoASH → Acetyl-S-CoA + NADH + CO₂

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

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

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

Identify the event that exclusively occurs in meiotic cell division

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

Considering environment and ecosystem, identify the INCORRECT statement

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

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

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

Q. 56 - Q. 65 carry two marks each.

Q.

Identify the floral formula with the family and the corresponding plant species

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?

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

Identify the correct matching by taking one item from each column

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 + CO₂ → 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

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

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

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

Identify the correct matching by taking one item from each column

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
xylem loading
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

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

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

Shine Dalgarno’s sequence present in mRNA binds to

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

The most common indicator organism of faecal pollution in water is

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

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

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

The enzyme that catalyzes the reduction of nitrogen to ammonia is

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

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

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

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

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

Match the scientists in Group I with their contributions in microbiology in Group II

Match the infectious agents in Group I with the associated diseases in Group II

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

Match the microscopes in Group I with their working principles in Group II

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.

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

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

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”?

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

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

The primary difference between glycogen and cellulose is in the

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?

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

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?

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

The term “ecological succession” refers to:

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

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

Q. 11 - Q. 20 carry two marks each

Q.

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

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

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?

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)

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

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