71.
You are studying the binding of proteins to the cytoplasmic face of cultured
liver cells and have found a method that gives a good yield of inside-out
vesicles from the plasma membrane. Unfortunately, your preparations are
contaminated with variable amounts of right-side-out
vesicles.
Nothing you have tried avoids this contamination. Somebody suggests that you
pass the vesicles over an affinity column made of lectin coupled to Sepharose
beads. What is the rational of this suggestion?
1. Right-side-out-vesicles
wIll be lysed by lectin coupled to Sepharose beads.
2.
Right-side-out-vesicles will simply bind to the lectin coupled Sepharose beads.
3. Lectin will bind
to the carbohydrate residues present only on the inside out vesicles.
4. Lectin will bind
to only glycoproteins and glycolipids present on the inside-out vesicles.
72.
The overall length of the cell cycle can be measured from the doubling time of
a population of exponentially proliferating cells. The doubling time of a
population of mouse L cells was determined by counting the number of cells in
samples of culture at various times. What is the overall length of the cell
cycle in mouse L cells?
1.
30 h
2.
20h
3.
10 h
4.
40 h
1.
0.0270
2.
0.0135
3.
0.00017
4.
0.0035
74.
A protein in 100 mM KCl solution was heated and the observed Tm (midpoint of
unfolding) was 60°C. When the same protein solution in 500 mM KCI was heated,
the observed Tm was 65°C. What is the most probable reason for this increase in
Tm?
1.
Hydrophobic interaction is increased and electrostatic repulsion is decreased.
2.
Hydrophobic interaction is decreased and electrostatic repulsion is increased.
3.
Hydrogen-bonding is increased.
4.
van der Waals interaction is increased
75.
During receptor-mediated endocytosis, apolipoprotein B on the surface of a LDL
particle binds to the LDL-receptor present in coated pits containing clathrin.
The receptor-LDL complex is internalized by endocytosis, trafficked to
lysosomes and the LDL-receptor is finally recycled.
A
patient reports with familial hypercholesterolemia. This could be due to
1.
mutation in the LDL molecule.
2.
defect in LDL-receptor recycling.
3.
mutation in the LDL-receptor.
4.
defect in cholesterol binding with its receptor.
76.
Budding yeast cells that are deficient for Mad2, a component of the
spindle-attachment-check point, are killed by treatment with benomyl, which
causes microtubles to depolymerise. In the absence of benomyl, however, the
cells are perfectly viable. Which explanation out of the
following
is able to justify this observation?
1.
In the absence of benomyl, the majority of spindles forms normally and the
spindle-attachment checkpoint (Mad2) plays no role.
2.
In the presence of be no my I, the majority of spindles form normally and Mad2
plays critical role in cell survival.
3.
Other than the role in cell survival, microtubule depolymerization affects
oxidative phosphorylation in the absence of Mad2.
4.
Benomyl also affects protein synthesis in the absence of Mad2.
77.
Eukaryotic genomes are organized into chromosomes and can be visualized at
mitosis by staining with specific dyes. Heat denaturation followed by staining
with Giemsa produced alternate dark and light bands. The dark bands obtained by
this process are mainly
1.
AT -rich and gene rich regions.
2.
AT -rich and gene desert regions.
3.
GC-rich and gene rich regions.
4.
GC-rich and gene desert regions.
78.
An amino acid contains no ionizable group in its side chain (R). It is titrated
from pH 0 to 14. Which of the following ionizable state is not observed during
the entire titration in the pH range 0 - 14?
79.
A researcher has isolated a restriction endonuclease that cleaves at only one
specific 10 base pair site.
A)
Would this enzyme be useful in protecting cells from viral infections, given
that a typical viral genome is 5 x 104 base pairs long?
B)
Restriction endonucleases are slow enzymes with turnover number of 1 s-1.
Suppose the isolated endonuclease was faster with turnover
numbers
similar to those for carbonic anhydrase (106 s-1),
would this increased rate be beneficial to host cells, assuming that the fast
enzymes have similar levels of specificity?
The
correct combination of answer is
1.
(A) : No (B) : Yes
2.
(A) : No (B) : No
3.
(A) : Yes (B) : No
4.
(A) : Yes (B) : Yes
80.
Lac repressor inhibits expression of genes in lac-operon whereas purine
biosynthesis is repressed by the Pur repressor. The two proteins have
31% identical sequences and have similar three-dimensional structures. The gene
regulatory properties of these proteins differ in relation
to
A)
binding of small molecules to the repressor.
B)
presence of recognition sites on the genome.
C)
oligomeric nature of the repressor.
D)
DNA binding property.
The
correct statements are
1.
A and B
2.
A, B and C
3.
A and C
4.
B, C and D
81.An
α-helix in a peptide or protein is characterized by hydrogen bonds and
characteristic dihedral angles. Choose the right combination.
1.
Hydrogen bonding between the amide CO of residue i and amide NH of residue i +
4. Dihedral angles in the region ϕ = -50°, ψ = -60°.
2.
Hydrogen bonding between the amide NH of residue i and amide CO of residue i +
4. Dihedral angles in the region of ϕ = -50°, ψ = -60.
3.
Hydrogen bonding between the amide CO of residue i and amide NH of residue i +
4. Dihedral angles in the region of ϕ = -50°, ψ = +60
4.
Hydrogen bonding between the amide CO of residue i and amide NH of residue 1 +
3. Dihedral angles in the region of ϕ = -50°, ψ = -60
82.
Mouse bone marrow cells were fractionated to derive stem cell antigen-1+ (Sca-1+)
cells. These cells were cultured with interleukin-3, or granulocyte-macrophage
colony stimulating factor, or macrophage-colony stimulating factor, or
granulocyte colony stimulating factor. Most numerous and varied colonies were
obtained in the culture stimulated with
1.
Interleukin-3
2.
Granulocyte-macrophage colony stimulating factor.
3.
Macrophage-colony stimulating factor.
4.
Granulocyte-colony stimulating factor
83.
Precursors of the atoms in the purine skeleton are
1.
N1, Asp; C2 and C8, formate; N3 and N9 guanidine C4, C5 and N7, Gly; C6, C02.
2.
N1, Asp; C2 and C8, citrate; N3 and N9, amide nitrogen of Gln, C4,,C5 and N7;
Gly; C6, C02.
3.
N1, Asp; C2 and C8, formate; N3 and N9 amide nitrogen of Gln, C4, C5 and N7,
Gly; C6, C02.
4.
N1, Glu; C2 and C8, acetate; N3 and N9, amide nitrogen of Asn; C4, C5 and N7,
Gly; C6, C02.
84.
Two E. coli cultures A and B are taken. Culture A was earlier grown in
the presence of optimum concentration of gratuitous inducer IPTG.
Both
the cultures are now used to inoculate fresh medium containing sub-optimal
concentration of gratuitous inducer. It was observed that culture B was unable
to utilize lactose, whereas culture A did so efficiently. The reason behind
this is
1.
pretreatment with IPTG has resulted in a mutation as a result of which lac
operon is constitutively expressed
2.
IPTG has made the cell membrane more porous to small molecu1es and so lactose
is taken up more efficiently by A as compared to B.
3.
in culture A, lactose permease was induced to a high level, during pretreatment
with IPTG, which allowed the preferential uptake of lactose.
4.
in culture A, IPTG activated a receptor which bound lactose more efficiently,
thereby triggering a signal.
85.
Cancer causing genes can be functionally classified into mainly three types:
(i)
genes that induce cellular proliferation,
(ii)
tumor suppressor genes,
(iii)
genes that regulate apoptotic pathway.
Epstein-Barr
virus that causes cancer by modulating apoptotic pathway, contains a gene
having sequence homology with which of the following
genes?
1.
bax
2.
bcl-2
3.
p53
4.
caspase-3
86.
It has been observed that in 5-10% of the eukaryotic mRNAs with multiple AUGs,
the first AUG is not the initiation site. In such cases, the ribosome skips
over one or more AUGs before encountering the favorable one and initiating
translation. This is postulated to be due to the
presence
of the following consensus sequence (s):
A)
CCA CC AUG G
B)
CCG CC AUG G
C)
CCG CC AUG C
D)
AAC GG AUG A
Which
of the following sequence sets related to the above postu1ations is correct?
1.
A and B
2.
A and C
3.
C and D
4.
B and D
87.
Values of Tm (midpoint of denaturation), ΔHm (enthalpy
change at Tm) and ΔCp
(constant-pressure heat capacity
change) of a protein are measured in a differential scanning calorimeter. ΔGD(T),
the Gibbs free energy change at any temperature T(K) can be estimated using the
following
form of the Gibbs-Helmholtz equation with the values obtained from these
measurements:
ΔGD(T)
= ΔHm – ΔCp
[Tm-T + Tln (T/Tm)]
The
stability curve for the protein simulated using the observed thermodynamic
values is given below:
The
shape of the stability curve is due to
1.
hydrogen-bonding and electrostatic interactions only.
2.
van der Waals and electrostatic interactions only.
3.
only electrostatic interactions.
4.
only hydrophobic interaction.
88.
Toll-like receptor 4 is associated with responsiveness to LPS, an endotoxin
that causes lethal endotoxic shock. The mice deficient In Toll-like receptor 4
and BALB/c mice were injected with Escherichia coli. In addition, some BALB/b
mice were also injected with the same bacteria alone
or
with anti-interleukin-10 (IL-10) antibody. The mice resistant to the lethal
effect of the bacteria were:
1.
BALB/b mice receiving the bacteria.
2.
BALB/b mice receiving the bacteria and the anti-IL-10 antibody
3.
Mice deficient In Toll-like receptor
4.
BALB/c mice receiving the bacteria.
89.
Presence of circular mRNAs for a specific protein in an eukaryotic cell
reflects a rapid rate of synthesis of that protein. Following mechanisms are
suggested:
A)
eIF-4G and PABP promote this process through 5'-3' interaction of mRNA.
B)
ribosomes are less active in recognizing circular mRNA.
C)
PABP and eIF-4A promote this process.
D)
ribosomes can reinitiate translation without being disassembled.
Which
of the following is correct?
1.
A and D
2.
B and D
3.
A and C
4.
B and C
90.
siRNAs and miRNAs are used for achieving gene silencing. Although, major steps
are similar there are distinct differences in the key players of the two
processing pathways. Following statements relate to some characteristic
features of gene silencing.
A)
Both siRNAs and miRNAs are processed by cytoplasmic endonuclease Dicer.
B)
'Drosha' is needed for processing miRNAs and precursor siRNAs.
C)
Both siRNAs and miRNAs show association with Argonaute protein.
D)
Both the processing pathways involve RISe complex.
Which
of the following combinations is NOT correct?
1.
A and C
2.
C and D
3.
A and B
4.
D and A
91.
Glucose is mobilized in muscle when epinephrine activates Gαs. In an experiment
in which muscle cells were stimulated with epinephrine, glucose mobilization
was observed even after withdrawal of epinephrine. This could be
1.
due to the presence of a cAMP phosphodiesterase inhibitor.
2.
very low rates of cyclic AMP formation.
3.
due to the presence of a cAMP phosphodiesterase activator.
4.
due to the absence of protein kinase A.
92.
In eukaryotic chromatin, 30 nm fiber (solenoid) can open up to give rise to two
kinds of chromatin. In one type (A), the promoter of a gene within the open
chromatin is occupied by a nucleosome whereas in the other (B), the promoter is
occupied by histone H1. The following
possibilities
are suggested.
A)
The gene in (A) is repressed.
B)
The gene in (B) is repressed.
C)
The gene in (A) is active.
D)
The gene in (B) is active.
Which
of the following sets is correct?
1.
A and D
2.
A and B
3.
Band D
4.
C and D
93.
Intracellular pathogens like Mycobacteria, Salmonella, Leishmania and
Listeria survive in macrophages by modulating host cellular machinery.
In order to study the fate of these intracellular pathogens in macrophages,
cells were labeled with lysotracker Red arid infected with
GFP-Iabelled
organisms. After 2 hours at 37°C, cells were fixed, stained with anti-transferrin
receptor antibody and probed with secondary antibody conjugated-blue dyes.
Cells were viewed under confocal microscope.
Observation: GFP-labelled
Mycobacteria, Salmonella and Listeria were localized in the same
compartment labelled with blue dyes; whereas
GFP-Leishmania
colocalize with red labelled compartment.
Which
of the following statement is true based on these observations?
1.
Mycobacteria, Salmonella and Listeria reside in the lysosomes.
2. Leishmania
reside in lysosome like compartment
3.
Leishmania reside in a compartment which bears characteristics of early
endocytic compartment.
4.
Mycobacteria, Salmonella and Listeria lyse the phagosomal
membrane and reside in cytosol.
94.
Macrophages were collected from BALB/c mice, CD40-deficient mice, CD86-
deficient mice and ICAM-1-deficient mice.
These
macrophages were co-cultured with LCMV peptidespecific T cells in presence of
the LCMV peptide for three days. The cells were recovered and co-cultured with
BALB/c-derived macrophages in presence of the peptide. During the last twelve
hour of the co-culture, 3Hthymidine
was
added to the cultures.
The
cells were harvested and 3H- thymidine incorporation was assessed. The highest
incorporation was observed in
1.
BALB/c macrophage-T cell co-culture.
2.
CD40-deficient macrophage-T cell co-culture.
3.
CD86-deficient macrophage-T cell co-culture.
4.
ICAM-1-deficient macrophage-T cell co-culture.
95.
Genetic studies demonstrated that TBP mutant cell extracts are deficient in
transcription of genes from all three promoters viz. class I, II and III.
Following statements describe characteristic features of TBP.
A)
TBP is considered as an universal basal transcription factor.
B)
TBP is not required for transcription of archaeal genes.
C)
TBP is involved in recognizing TATA box.
D)
TBP operates at all promoters regardless of .their TATA content.
Which
of the following combinations is NOT correct?
1.
A and D
2.
C and D
3.
B and D
4.
A and C
96.
cAMP signalling plays a very important role in the development and differentiation
of Dictyostelium discoideum. This morphogen is synthesized by different
adenyl cyclases expressed at different stages of its life cycle. The following
statements (A-D) refer to the effect of
mutations
in different adenyl cyclase genes:
A)
aca deficient cells can be a1l0wedto aggregate by exposing them to
pulses of cAMP.
B)
acb deficient cells would form normal fruiting bodies and the spores can
germinate when exposed to favorable conditions.
C)
acg deficient cells develop normally and the spores germinate in the
spore head itself.
D)
spores formed from the acg deficient cells will germinate irrespective
of the osmotic conditions.
Which
of the above statements are correct?
1.
A and D.
2.
A only.
3.
A and B.
4.
C and D.
97.
Fill in the blanks (a, b, c and d) in the following statements with a proper
combination of m, n, 0 and p. Where in
m
represents – longer
n
represents - shorter
o
represents -prevents
p
represents – induces
Short
day (SD) plants flower when night lengths are _____a____ than a critical
dark period. Interruption of the dark period by a brief light
treatment
______b_____ flowering in SD plants. Long day (LD) plants flower when
night length is ______c_____ than a critical period.
Shortening
of the night with a brief light treatment _______d_____ flowering in LD
plants.
98.
The total variance in a phenotypic character can be split into two components -
genetic (VG) and environmental (VE). The heritability
of a phenotypic trait can be expressed quantitatively as heritability coefficient
(h2) which is calculated as h2=
1.
VG-VE
2.
VE/VG
3.
VG/(VG+VE)
4.
VG/(VG-VE)
99.
Mutations in CONSTANS (CO) of Arabidopsis thaliana results in
late flowering phenotype. Transcript levels of CO were determined in long day
and short day seedlings. Which of the following would likely represent the
transcript profile of CO?
100.
Following are some statements for synthesis of secondary metabolites in plants.
A)
Terpenes are synthesized by shikimic acid pathway and mevalonic acid pathway.
B)
Alkaloids are nitrogen containing compounds and are synthesized by shikimic
acid pathway.
C)
Phenolic compounds are synthesized by shikimic acid pathway and mevalonic acid
pathway.
D)
Both alkaloids and terpenes are synthesized by mevalonic acid pathway and MEP
pathway.
Which
one of the following combinations of the above statement is true?
1.
A and D
2.
A and C
3.
B and C
4.
B and D
101.
During early cleavage of Caenorabditis elegans embryos, each
asymmetrical division produces one founder cell which produces differentiated
descendants and one stem cell. The very first cell division produces one
anterior founder cell, namely AB and one posterior stem cell, namely P1. When
these blastomeres are experimentally separated and allowed to proceed further
with development, one could get the following possible outcomes:
1.
P1 cell would develop autonomously while the AB would show conditional
development.
2.
P1 cells would show conditional development while AB would show autonomous
development.
3.
Both would show autonomous specification and result in mosaic development.
4.
Both would show conditional specification and result in regulative development.
102.
In case of sea urchin, which of the following is the correct sequence of events
taking place during the interaction of sperm and egg?
1.
Chemoattraction of sperm to the egg by soluble molecules secreted by the egg → exocytosis of the sperm acrosomal vesicle to release its
enzymes
→ binding of the sperm to the extracellular matrix of the
egg → passage of sperm through this extracellular matrix → fusion of egg and sperm cell membranes.
2.
Chemoattraction of sperm to the egg by soluble molecules secreted by the egg → binding
of the sperm to the extracellular matrix of the egg → exocytosis of the sperm
acrosomal vesicle to release its enzymes → passage of sperm through this
extracellular matrix → fusion of egg and
sperm
cell membranes.
3.
Chemoattraction of sperm to the egg by soluble molecules secreted by the egg → binding of the sperm to the extracellular matrix of the
egg → passage of sperm through this extracellular matrix → exocytosis of the sperm acrosomal vesicle to release its
enzymes → fusion of egg and
sperm
cell membranes.
4.
Chemoattraction of sperm to the egg by soluble molecules secreted by the egg → passage of sperm through this extracellular matrix →binding of the sperm to the extracellular matrix of the egg
→ exocytosis of the sperm acrosomal vesicle to release its
enzymes → fusion of egg
and
sperm cell membranes.
103.
The time taken for atrial systole and diastole in a normal heart are tas and
tad seconds, respectively. If ventricular systole takes tvs seconds, calculate
the ventricular diastolic time (seconds)
1.
(tas+ tad) - tvs
2.
(tas- tad) + tvs
3.
(tad- tas) - tvs
4.
(tas+ tad) x tvs
104.
A patient undergoes liver transplantation and during the course of
post-operative treatment, becomes susceptible to infection. The patient can be
treated in two different modes and can have alternative outcomes. Which of the
following statements is correct?
1.
Treatment with immunostimulatory drugs reducing the infection but rejecting the
transplant.
2.
Treatment with immunostimulatory drugs reducing the infection and retaining the
transplant.
3.
Treatment with antibiotics reducing the infection but retaining the transplant.
4.
Treatment with antibiotics reducing the infection but rejecting the transplant.
105.
The dependence of the rate of sucrose uptake with respect to sucrose
concentration in plant cell was studied and data are shown in the following
graph.
From
the above data it can be inferred that
1.
the sucrose uptake is energy independent and no special carrier is involved.
2.
the sucrose uptake is energy dependent and a special carrier is involved.
3.
at lower concentration of sucrose the uptake of sucrose is energy dependent and
carrier ediated.
4.
at higher concentration of sucrose the uptake is energy dependent and carrier
mediated.
106.
During episodes of anoxia in plants, pyruvate produced in glycolysis is
initially fermented to lactate. During later stage, there is an increase in the
fermentation to ethanol and decrease in the fermentation to lactate, a
phenomena which s plants survive anoxia. Which of the following statements is
correct about this change of fermentation flux from lactate towards ethanol?
1.
The cytosolic pH increases, thus activating both lactate dehydrogenase and
pyruvate decarboxylase activity.
2.
The cytosolic pH increases, thus inhibiting lactate dehydrogenase activity and
activating pyruvate decarboxylase activity.
3.
The cytosolic pH decreases, thus activating both lactate dehydrogenase and
pyruvate decarboxylase activity.
4.
The cytosolic pH decreases, thus inhibiting lactate dehydrogenase and
activating pyruvate decarboxylase activity.
107.
Bacteria often acquire genes by the process of lateral or horizontal transfer.
Such 'foreign' genes, if acquired in recent past, may be identified by their
atypical GC content, as compared to 'native' genes. Suppose the genomic GC
content of a bacterium is 40%. Gene A of this organism contains 1000 bases with
225 G and 215 C. Another gene B of length 800 bases contains 160 G and 140 C. Which
one of the following would be the most
acceptable hypothesis (given that x2= 3.841 at 0.05
significance level)?
1.
A: native, B: Foreign
2.
A: Foreign, B: Native
3.
A: Foreign, B: Foreign
4.
A: Native, B: Native
108.
Injection of noggin mRNA into a 1-cell, UV-irradiated embryos of frog
completely rescues dorsal development and allows the formation of a complete
embryo. Some of the following statements (A-D) could possibly explain this
observation.
A)
Noggin is a secreted protein which induces dorsal ectoderm to form neural
tissue and it dorsalizes the mesoderm cells which would otherwise
contribute
to ventral mesoderm.
B)
Noggin binds directly to BMP4 and BMP2 thus preventing complex formation with
their receptors.
C)
Noggin along with other molecules prevent BMP from binding to and inducing
ectodenn and mesoderm cells near the organizer.
D)
Noggin is a secreted protein which induces the dorsal ectoderm to form the
epidermis and it ventralizes the mesoderm cells which would otherwise
contribute to dorsal mesoderm.
Which
of the above statements are correct?
1.
A, B and C.
2.
A and B.
3.
B and C.
4.
A and D
109.
Atmospheric CO2 contains the naturally occurring stable carbon isotopes 12C
and 13C in the proportion of 98.9% and 1.1%, respectively.
Following
are some of the statements regarding CO2 assimilation:
A)
Both C3 and C4 plants assimilate less 13CO2 than 12CO2.
B)
Both C3 and C4 plants assimilate less 12CO2 than 13CO2.
C)
C3 plants assimilate lesser 13CO2 than 12CO2 as compared to C4 plants.
D)
C4 plants assimilate lesser 13CO2 than 12CO2 as compared to C3 plants.
Which
one of the following combinations of above statements is true?
1.
A and B
2.
A and C
3.
C and D
4.
A and D
110.
Spinal cord of an animal was transected at C1/C2 level. The respiration of the
animal stopped and it needed artificial respiration. However, the heart
continued to beat although at a slower rate. Some of the explanations given
were:
A)
respiration regulatory centre is located in the medulla.
B)
respiration regulatory centre is located above the C1/C2 cut.
C)
heart regulatory centre is above the C1/C2 cut.
D)
heart has autoregulation.
Which
one of the following is most appropriate?
1.
A only.
2.
B and C only.
3.
A, B and D only
4.
B, C and D only.
111.
An organism having heart for circulation, excretes through green glands. It has
several ganglia and tactile organs on its body and its larval form is very
different than its adult form.
This
organism most likely to respire by:
A)
exchanging oxygen and carbon dioxide through an extensive tracheal system.
B)
gaseous exchange over thinner areas of cuticle or by gills
C)
an efficient tracheal system that delivers oxygen directly to the tissues
D)
a double transport system, where the circulating fluid contains a dissolved
respiratory pigment.
Choose
the correct option.
1.
A and C
2.
Only D
3.
Only B
4.
B and D
112.
The MALDI spectrum of a peptide shows a peak at m/z corresponding to
3600. When the ESI spectrum is recorded, peaks at m/z corresponding to
721,904 and 1801 were obtained. When the MALDI MS/MS spectrum was recorded,
large number of peaks with m/z less than 3600 were observed.
The
spectral data indicate that the peptide is
1.
highly impure.
2.
pure with molecular mass of 3600 and partial sequence of the peptide can be determined.
3.
highly unstable and degrades rapidly.
4.
degraded under condition employed for recording ESI spectrum.
113.
In a stressful condition, ACTH secretion was increased and as a result
glucocorticoid concentration was elevated in blood. One or a combination of the
following changes most likely taking place in this condition:
A)
Decreased circulating eosinophils and basophils.
B)
Reduced IL2 release.
C)
Potentiated inflammatory response to tissue injury.
D)
Increased mitotic activity of lymphocytes in lymph nodes.
The
correct answer is
1.
B and C.
2.
A and B.
3.
B and D.
4.
C and D.
114.
In one study, a group of 5 day rat pups were fed for 3 weeks a diet A and the
pups gained weight by 300%. In a second study, when the same diet fed for 3
weeks to rats of 350 gms, they did not gain weight significantly. In a third
study, a diet B was fed to 250-350 gms rats and it was
observed
that they delivered normal pups after five weeks. Based on these observations
which of the following statements is correct?
1.
Diet A facilitates weight gain than diet B.
2.
Diet B facilitates pregnancy and child-bearing.
3.
More control experiments are to be conducted for definitive conclusion.
4.
Diet A is more energy containing that diet 'B'. Hence, its quantity should be reduced.
115.
In Neurospora a cross between the genotypes 'A' and 'a' results
in an ascus with ascospores of genotypes as shown below:
A)
Crossing over between the centromere and the gene.
B)
Segregation of alleles 'A' and 'a' in meiosis I.
D)
Assortment of alleles 'A' and 'a'.
Which
of the above events could correctly explain the observation shown in the
figure?
1.
A followed by C 2. C alone 2. A followed by B 4. D
alone
116.
Which of the following graph represents normal sexual cycle in a normal human
female?
117.
Based on the structural regions of a nuclear receptor shown in the diagram, the
following predictions were made.
A)
Region F is responsible for binding to ligands and contains two zinc
finger-like binding motifs
B)
Receptors with A/B domains generally associate with chaperones and do not bind
to DNA.
C)
Region E indicate that receptors associate with chaperones which protect the
nuclear hormone receptors.
D)
Region C contains the P-box and the D-box required for dimerization of the
receptor and creates contact with DNA phosphate backbone.
Which
one of the following is true?
1.
A and B
2.
B and C
3.
B and D
4.
C and D
118.
When F1 female Drosophila of the genotype a+a b+b c+c
is test crossed, the following progenies were obtained:
*The
progeny has been shown as classes derived from the female gamete.
Statements
A to F as given below are conclusions derived from the above result.
A)
Genes a and b are linked in cis.
B)
Genes a and b are linked in trans.
C)
Genes a and b are linked in cis while b and c are
linked in trans.
D)
The genotype of the parents are a+a+b+b+ and aabb
E)
The genotype of the parents are a+a+bb and aab+b+.
F)
Genes a and b are 10cM apart.
Which
of the above statements are correct?
1.
C alone.
2.
A, E and F.
3.
B, E and F.
4.
A, D and F.
119.
Monoclonal antibodies (mAb) can be potentially used as therapeutic agents. The
major advantage is that they can specifically target aberrant cells. However,
there is a practical difficulty. Monoclonals are raised in mouse and therefore
it is expected that an immune reaction will
develop
if these are injected into humans. It is therefore necessary to 'humanize'
monoclonal antibody by
1.
expressing the genes for the mAb in cultured human cells and isolating the mAb
from these cells
2.
replacing the Fv region of a mAb with one derived from a human IgG
3.
replacing CL and CH regions of the Mab with that obtained from a human IgG.
4.
taking a human IgG and replacing the CDRs by those derived from the mouse mAb
120.
The following is a hypothetical pathway for the development of wild type (red)
eye color in an insect: Enzymes A and B are encoded by the genes a+ and b+,
respectively.
The
following statements are made regarding inheritance of the genes involved in
the development of eye color:
A)
When two heterozygous individuals of the genotype a+ab+b are
mated, progenies with red, orange, brown and white eye colour will be
observed
irrespective of whether the genes are independently assorting or showing
incomplete linkage.
B)
When two heterozygous individuals of the genotype a+a/b+b are
mated, progenies with red, orange, brown and white eye colour will be
observed
in a ratio of 9:3:3:1,when the genes are independently assorting.
C)
When an heterozygous individual of the genotype a+b/a b+ is test
crossed, progenies with red and white eye colour will be more in number.
D)
When an heterozygous individual of the genotype a+b/a b+ is test
crossed, progenies with orange and brown eye colour will be more in
number.
Which
of the above statements is TRUE?
1.
A and C
2.
B and C
3.
A, B and C
4.
A, B and D
121.
Mendel crossed tall pea plants with dwarf ones. The F1 plants were all tall.
When these F1 plants were selfed to produce F2 generation, he got a 3: 1 tall
to dwarf ratio in the offspring. What is the probability that out of three
plants (of F2 generation) picked up at random two would be
dwarf
and one would be tall?
1.
3/4
2.
3/8
3.
9/64
4.
9/32
122.
Two new plant species, A and B, were described in 1872. Subsequently it was
found that the type for species A was never designated and for species B there
was one specimen designated as type but missing. As per International Code of
Botanical Nomenclature (ICBN), typification
should
be
1.
neotype for A only.
2.
neotype for A and lectotype for B.
3.
neotypes for both A and B.
4.
lectotype for both A and B.
123.
According to MacArthur and Wilson's equilibrium theory, which of the following
is true?
1.
Larger islands and islands closer to continent are expected to have more
species than smaller and isolated islands.
2.
Smaller islands and islands far from the continent are expected to have more
species than larger and isolated islands.
3.
Smaller islands and islands closer to the continent are expected to have more
species than far away smaller and isolated islands.
4.
More species are expected on all islands irrespective of their size and
distance from the continent.
124.
Proteins in cells can be visualized by the following methods:
A)
Express the gene (coding for the said protein) as a fusion with the green
fluorescence protein (GFP) and directly visualize under a fluorescence
microscope.
B)
Express the gene (coding for the said protein) as a fusion with the
β-galactosidase gene (lac Z) and directly visualize under a phase
contrast bright field microscope.
C)
A fluorescence tagged antibody raised against the said protein could be used
for visualization in a fluorescence microscope.
D)
Over express the protein and directly visualize it under a scanning electron
microscope.
Which
of the following methods you would choose to visualize a protein in a living
cell?
1.
A only
2.
A and C only
3.
A and B only
4.
D only
125.
Affected individuals from the pedigree given below are suffering from albinism,
an autosomal recessive disease. Identify the confirmed carrier individuals in
this pedigree assuming that the members coming from outside the family are
homozygous for the dominant allele.
1.
III-2, 1II-3, III-5, 1II-6, II-I, II-3 and II-6
2.
III-2, III-3, III-5, 1II-6, II-2, II-4, II-5 and I-2
4.
III-I, III-4, III-7, II-2, II-4 and II-5
126.
Assume a new subspecies Ficus callosa subsp. Microcarpa has been
published by Jacobs. The nomenclature of the resulting entities would be
1.
F callosa and F. callosa subsp. microcarpa Jacobs
2.
F. callosa subsp. microcarpa Jacobs and other yet to be named
subspecies of F. callosa
3.
F. callosa subsp. callosa Jacobs and F.callosa subsp. microcarpa
Jacobs.
4. F.
callosa subsp. callosa and F.callosa subsp. Microcarpa Jacobs.
127.
Primary production in aquatic ecosystem is measured using Light-and-Dark-Bottle
technique. In this method, as an indirect measure of photosynthetic production,
dissolved oxygen concentration of the pond water enclosed in a BOD bottle is
measured initially (I) and after a fixed
duration
of incubation in a light bottle (L) and a dark bottle (D). Then, the gross and
net primary productions are estimated is
1.
(L-D) and (L-I), respectively.
2.
(L-I) and (L--D), respectively.
3.
(L-I) and (I-D), respectively.
4.
(L-D) and (I-D), respectively.
128.
Identify the most appropriate cladogram that can be constructed using the data
matrix given below, assuming ‘0’s are pleisomorphic and‘1’s are apomorphic
characters.
129.
Gause's 'Competitive exclusion' principle states that two species with
identical niches cannot coexist indefinitely. Which of the following statements
is the most appropriate regarding the validity of the principle?
1.
It depends on how one defines niche.
2.
There are in nature many instances of continued coexistence of closely related
species.
3.
The principle is universally true.
4.
It does not predict the outcome where, both the species are equally strong
competitors.
130.
In a lake ecosystem, bottom-up effects (B) refers to control of a lower trophic
level by the higher trophic levels and top down effects (T) refer to the
opposite. In a lake with three trophic levels - Phytoplankton (P), Zooplankton
(Z) and Carnivore (C),
1.
P and C are controlled by B, and Z is controlled by T
2.
P, Z and C are all controlled by T
3.
P is controlled by B, Z is controlled by T and C is controlled by B
4.
P is controlled by T, Z is controlled by B and C is controlled by T
131.
An organism has the following architectural pattern:
(i)
multicellular with germ layers
(ii)
a coelom derived from the mesoderm
(iii)
primary bilateral symmetry with secondary radial symmetry
(iv)
presence of endoskeletal plates
Such
an organism is most likely to
(A)
have mesohyl as its connective tissue.
(B)
undergo torsion, whereby the mouth and anus are properly oriented.
(C)
be devoid of a brain but have calcareous spicules.
(D)
have comb plates to in locomotion.
Which
of the following is true?
1.
A and C
2.
C only
3.
D only
4.
B and C
132.
Identify the apomorphic characters marked in the cladogram:
1.
a - amniotic egg; b - 4-chambered heart; c-anapsidian skull; d-diapsidian
skull; e-synapsid skull.
2.
a - amniotic egg; b-synapsidan skull; c--4 -chambered heart; d. anapsidan
skull; e-diapsidan skull.
3.
a - 4-chambered heart; b-synapsid skull; c-amniotic egg; ddiapsidan skull;
e-anapsidan skull.
4.
a - amniotic egg; b - synapsidan skull; c-anapsidan skull, d. diapsidan skull;
e-4-chambered heart.
133.
The graph below shows the relationships of per capita population growth rate (r),
fecundity (b) and age at first reproduction (α) in
an animal species.
What
is the most important conclusion to be drawn from the graph?
1.
The later the age of first reproduction, the lower is the population growth
rate achieved.
2.
The population growth rate decreases as first reproduction is postponed to a
later stage, regardless of the fecundity.
3.
At any α, the higher the fecundity, the higher is the population growth rate
achieved.
4.
As the age at first reproduction is postponed further, the benefits of
increasing fecundity on the population growth rate become progressively negligible.
134.
What will be the approximate effective population size in a panmictic
population of 240 with 200 females and 40 polygamous males?
1.
160
2.
133
3.
63
4.
67
135.
An animal was first maintained in a constant environmental condition for
several days until a consistent biological rhythm (B) was established. The
animal was then exposed to an experimental physical rhythm (E), which modulates
the phase and period of B. However, upon withdrawal of E, the B gradually
regained its pattern of preexposure condition. From these observations which
one or more of the following should be the most logical inference?
A)
E is a Zeitgeber.
B)
E is a masking agent.
C)
E causes entrainment of B.
D)
B is a conditioned to E.
The
correct answer is
1.
A and C
2.
B and D
3.
B only
4.
D only
136.
Shown in the graph below are the fitness costs and benefits of four
alternatives behavioural phenotypes (P,Q,R,S). Given sufficient evolutionary
time, which phenotype(s) is likely to evolve as an adaptation?
1.
Q and R
3.
P, Q and R
4.
S only
137.
The following geological eras mark the advent of important events in the
history of earth - origin of terrestrial plants, origin of mammals and break up
of the land mass Pangaea:
(a)
Early Cambrian
(b)
Late Devonian
(c)
Late Cretaceous
(d)
Late Jurassic
Identify
the correct match of the events with the geological era
1.
Origin of terrestrial plants - (c); Origin of mammals (d); Break-up of Pangaea
- (a)
2.
Origin of terrestrial plants - (b); Origin of mammals (d); Break up of Pangaea
–(c)
3.
Origin of terrestrial plants - (d); Origin of mammals (c); Break up of Pangaea
–(b)
4.
Origin of terrestrial plants - (b); Origin of mammals (c); Break up of Pangaea
–(d)
138.
Industrial products in which bacteria are employed for production are shown in
the following table:
I.
List of products II. Microorganims
A.
2,3-Butane diol i) Leuconostoc
B.
Dextran ii) Brevibacterium
C.
Glutamic acid iii) Bacillus polymyxa
D.
Cobalamine iv) Propionibacterium
The
correct combinations are
1.A - iii; B – i; C – ii; D - iv
2.
A - i; B - ii; C - iii; D - iv
3.
A - iii; B - ii; C - iv; D – i
4.
A - ii ; B - iii; C - iv; D – i
139.
Insertion lambda vectors are used to create cDNA libraries, In some insertion
vectors, the site of insertion is within the cI gene. The, recombinants which
are cI- can then be screened by plating on E. coli hfl. The gene hfl
encodes a protease that controls lytic-lysogeny decision through which
mechanism?
1.
Hfl protease degrades cI, thereby promoting lytic pathway
2.
Hfl protease degrades cIII and so cllI cannot interact with CII, lysogenic
pathway is thus preferred.
3.
Hfl protease degrades cII, and therefore cI synthesis cannot be established,
thus lytic pathway is preferred.
4.
Hfl protease degrades INT, the protein involved in phage integration and the
lytic pathway is initiated.
140.
A transposon carrying a promoterless β-galactosidase (lac Z) was used to
create insertional mutation in the vir region of Ti-plasmid of Agrobacterium
tumefaciens. All the mutants in which lac Z fusion was in frame were
divided into the following three groups:
A)
The virulence of the bacteria was completely lost and the lac Z was
induced by acetosyringone.
B)
The virulence of the bacteria was reduced and the lac Z was induced
by acetosyringone.
C)
The virulence of the bacteria was completely lost and lac Z was not
induced by acetosyringone.
Which
of the following assumptions are valid about these mutants?
1.
In group A, the insertion could be in vir B, C. D or G; in group B the
insertion could be in virC or E; and in group C the insertion could be in virA or
G.
2.
In group A, the insertion could be in virA, B, C or D; in group
B, the insertion could be in either virC or D; and in group C the
insertion could
be
in virG.
3.
In group A, the insertion could be in virA; in group B, the insertion
could be in vir B; and in group C, the insertion could be in vir C.
4.
In group A, the insertion could be in virG; in group B, the insertion
could be in virB, D and E; in group C, the insertion
could
be in virA.
141.
A 30-residue peptide was treated with trypsin and the tryptic peptides were
separated by HPLC. Four peaks A, B, C and D were obtained.Peptides
corresponding to A, B, C and D were reduced and alkylated selectively at
cysteine residues. The sequences obtained from A, B, C and D after reduction
and alkylation were: A, AEK; B, C(S-alkyl)EPGYR and WC(Salkyl) SPPK;
C,C(Salkyl) EHFR and C(S-alkyl)GGK; D, C(Salkyl)EAFC(S-alkyl)L. The sequence of
the 30-residue peptide is
142.
To detect mutation (GAGGTG)
allele specific hybridization method is used. Four members of an affected
family are investigated. DNA isolated from blood samples of parents and two
offsprings are spotted on a membrane after appropriate processing and probed
with either
TGACTCCTGAGGAGAAGTC
(first probe) or TGACTCCTGTGGAGAAGTC (second probe) after labelling. While
probed with first oligonucleotide, signals are obtained for the positions where
DNA are spotted from parents and offspring II. When probed with second oligonucleotide,
signals are obtained at position where DNA from the parents and offspring I are
spotted. Results are shown below:
On
the basis of the result, which of the following statements is correct?
1.
Parents are affected
2.
Offspring I is affected
3.
Offspring II is carrier
4.
Offspring II is affected
143.
Molecular beacons (MB) and Taqman (TQ) are used as probes in Real time PCR
experiments. Both these probes are based on the principle of FRET and employ a
fluorophor (F) and a quencher (Q). However the mechanisms by which they
function are different as illustrated below At what stage of the PCR we would
be able to detect fluorescence?
1.
Annealing step for both.
2.
Extension step for both.
3.
Annealing for A and Extension for B.
4.
Extension for A and Annealing for B.
The
results obtained are tabulated below
A)
The transformation is dependent on recombination between homologous sequences.
B)
Cells did not distinguish between homologous or heterologous sequences for
uptake of DNA.
C)
DNA uptake is based on specific receptors
D)
DNA degradation dictates transformation efficiency Which of the following
interpretations are correct?
1.
A and B
2.
A and C
3.
C and D
4.
A and D
145.
When a wrist blastema from a recently cut Axolotl forelimb is placed on
a host hindlimb cut at the mid thigh level, it will generate only a wrist. The
host (whose own hind limb was removed) will fill the gap and regenerate the
limb upto the wrist. However if the donor blastema is treated with retinoic
acid on grafting, the wrist blastema will regenerate a complete limb and will
not allow the host to fill the gap. This happens because retinoic acid
1.
s in proximalization of the blastema and activates the Hox genes differentially
across the blastema.
2.
s in the distalization of the blastema and activates the Hox genes
differentially across the blastema.
3.
s block the receptors of FGF essential for limb development
4. s
vigorous proliferation of the cells at the cut surface.
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