Previous Year Questions

QUESTION ID:2

The lifetime of a peptide bond in proteins is very large (~1000 years). Which statement below is INCORRECT with respect to stability of the peptide bond?  

QUESTION ID:3

Following are certain statements related to eukaryotic DNA replication:

A. The genome of multicellular animals contain many potential origins of replication.

B. During early development, when embryos are undergoing rapid cell divisions, origin sites are uniformly activated.

C. "Pulse-chase" technique is used to label sites of DNA replication.

D. The rate of elongation of different DNA chains during genome replication varies drastically.

Which one of the following combinations of above statements is correct?  

QUESTION ID:4

A researcher wanted to immunize individuals of a particular area with viral infections. The researcher developed two different vaccine types (A and B) with the following properties. (i) When vaccine type A specific for a viral strain is administered to individuals, they develop strong neutralizing antibody response with very poor immunological memory. Hence it has to be administered in repetitive doses. (ii) When vaccine type B specific for a viral strain is administered to individuals, they fail to develop circulating antibody response at the time of infection but they develop strong immunological memory. If two viral strains V1 (incubation period-2 days) and V2 (incubation period-15 days) are likely to infect the area, which of the following vaccine combination would provide maximum immunization?  

QUESTION ID:5

The expression of a hypothetical gene was analyzed by Northern and Western blot hybridizations under control and induced condition. The results are summarized below Expression of genes can be regulated by:

A. control at transcription initiation

B. alternative splicing

C. control of translation initiation

D. protein stability

Which of the above regulatory mechanisms can explain the observations shown in the figures?  

QUESTION ID:6

For successful fertilization in sea urchin, interaction between the surface of the egg and acrosomal proteins, specifically a 30.5 kDa protein called bindin, is necessary. The following factors could affect this interaction and prevent fertilization:

A. Removal of egg jelly polysaccharides.

B. Removal of bindin receptors on the egg vitelline membrane.

C. Removal of bindin receptors from the egg jelly.

D. Removal of bindin receptors from a single cluster on the vitelline membrane.

Which one or the combination of the above statements is correct?  

QUESTION ID:7

A mutant embryo of Drosophila in which one of the major sex determining gene, sex lethal, can only undergo default splicing, was allowed to develop. The following statements are towards explaining the determination of sex of the embryo:

A. The embryo will develop into a male fly

B. The embryo will develop into a female fly

C. sex lethal gene product directly regulates sex specific alternate splicing of double sex RNA

D. sex lethal gene product regulates sex specific splicing of transformer RNA which in turn regulates splicing of double sex RNA

The correct combination of above statements to explain sex determination of the given embryo is:  

QUESTION ID:8

A two-celled embryo is made of blastomeres A and B. If the two blastomeres are experimentally separated, the 'A' blastomere generates all the cells it would normally make. However, the 'B' blastomere in isolation makes only a small fraction of cells it would normally make. Based on the above observations only, which one of the following conclusions is correct?  

QUESTION ID:9

A mutant was experimentally generated which had wings reduced to haltere like structure. The following statements are put forward regarding this phenotype:

A. ultrabithorax gene ectopically expressed in second thoracic segment

B. antennapedia gene ectopically expressed in second thoracic segment

C. A homeotic mutation,

D. A mutation in gap gene The following combination of statements will be most appropriate explaining the molecular basis of mutant phenotype:  

QUESTION ID:10

Following are certain statements regarding the activities of homeotic genes of classes A, B and C involved in floral organ identity:

A. Activity of A alone specifies sepals

B. Activity of B alone specifies petals

C. Activities of B and C form stamens

D. Activity of C alone specifies carpels

Which one of the following combinations of above statements is correct?  

QUESTION ID:11

Which one of the following statements about cell-cell interactions is NOT true?

A. Cadherins are transmembrane linker proteins which carry out Ca2+-mediated adhesion between adjacent cells.

B. Integrins are transmembrane adhesion proteins that mediate hemophilic adhesion through actin and intermediate  filaments.

C. Selectins are cell surface lectins that mediate a variety of transient, cell-cell adhesion interactions in the bloodstream.

D. ICAMs (intracellular cell adhesion molecules) and VCAMs (vascular cell adhesion molecules) are members of immunoglobulin (Ig) superfamily  

QUESTION ID:12

A technician wanted to make rabbit antiserum specific for mouse IgG. The technician injected rabbit with purified mouse IgG but obtained antiserum which reacted strongly with each of the other mouse isotypes. Which of the procedures mentioned below will allow him to make antiserum specific for IgG only?  

QUESTION ID:13

In order to precipitate a particular protein by its specific antiserum, it was found that the protein formed cross-linked lattice with specific polyclonal antiserum but failed to precipitate with specific monoclonal antiserum. Which of the following would accurately justify the reason for this behavior?  

QUESTION ID:14

You have isolated a short chain polypeptide from a bacteria which upon administering to animal cells in culture is demonstrated to get transported to mitochondria and to cause mitochondrial membrane disruption. This peptide is being considered for its therapeutic effects on cancer and is to be tested for its anticancer properties in the following models of the disease.

A. Cancer with Apaf-l mutation

B. Cancer where Box genes are inactivated

C. Cancer where Bok genes are inactivated

Which of the following is likely to provide best effect (i.e. induce apoptosis)  

QUESTION ID:15

Activation of the Wnt signal transduction pathway is extremely important during early development. Of the various pathways, which one of the following is most likely to induce cytoskeletal changes, like cell shape and movement?

QUESTION ID:16

A transgenic lettuce plant was generated by overexpressing isopentenyl transferase (IPT) gene under the control of the promoter of senescence activator gene (SAG12). Following are some statements regarding this transgenic plant. The transgenic plants

A. exhibit delayed senescence.

B. exhibit fast senescence.

C. have higher amount of cytokinin during senescence.

D. have higher amount of gibberellins during senescence.

Which one of the following combinations of above statements is correct?  

QUESTION ID:17

Following are certain statements regarding secondary metabolites found in plants:

A. All terpenes are derived from a six carbon element.

B. Alkaloids are nitrogen containing compounds.

C. Pyrethroids, a monoterpene ester found in the leaves and flower of Chrysanthemum species, show insecticidal activity.

D. Limonoids are groups of alkaloids and have anti-herbivoral activity.

Which one of the following combinations of above statements is correct?  

QUESTION ID:18

Light is crucial for plant growth and development. Following are certain statements related to photoreceptors in model plant Arabidopsis thaliana.

A. Among the five phytochrome genes, representing a gene family, PHYB plays a predominant role in red-light perception.

B. Cryptochromes are involved in the regulation of flowering time and hypocotyl length.

C. phyA photoreceptor is predominantly involved in far-red light perception.

D. The LOV domain of phytochrome C (pHYC) is an important domain for signal transmission.

Which one of the following combinations of above statements is correct?  

QUESTION ID:19

One of the important functions of program cell death (PCD) in plants is protection against pathogens. PCD also appears to occur during the differentiation of xylem tracheary elements that leads to nuclei and chromatin degradation. These changes result from the activation of certain genes. Following are certain genes encoding

A. Topoisomerase

B. Nuclease

C. RNA polymerase

D. Protease

Which one of the following combinations of the above is involved in differentiation of xylem tracheary elements?  

QUESTION ID:20

Following are some statements to osmotic stress in plants.

A. The accumulation of ions during osmotic adjustment is predominantly restricted to the vacuoles.

B. In order to maintain the water potential equilibrium within the cell, other solutes or compatible osmolytes accumulate in the cytoplasm.

C. Galactose is one of the compatible osmolytes involved in osmotic stress in plants.

D. There are mainly four groups of molecules that frequently serve as compatible solutes.

Which one of the following combinations of above statements is correct?  

QUESTION ID:21

Different frequencies of sound were presented on the ear and the movement of basilar membrane was experimentally determined. The characteristics of movement of basilar membrane after presentation of' 100 Hz sound are described in the following statements:

A. The base of basilar membrane showed resonance.

B. The apex of basilar membrane showed resonance.

C. A wave travelled from the base to apex of basilar membrane but the maximum displacement was noted near the apex.

D. A wave travelled from the base to apex of' basilar membrane but the maximum displacement was noted near the base.

Which one of the following is correct?  

QUESTION ID:22

The changes in left ventricular stroke work (LVSW) according to the different left ventricular end-diastolic pressures (LVEDP, which indicates the initial myocardial fiber length) in a dog, under control conditions, were recorded, which follows Starling's law of the heart. This LVSW-LVEDP relationship was investigated in the same dog after constant infusion of norepinephrine, and these two data sets were plotted. Which one of the following graphs correctly represents the results obtained?

QUESTION ID:23

When a nerve fiber is stimulated with increasing strength of stimulus, the action potential fails to generate even though the threshold level may be passed. The following statements may explain this accommodation of nerve fiber:

A. The critical number of open sodium channels required to trigger the action potential may never be attained due to slow depolarization.

B. Potassium channels open in response to slow depolarization, which makes the nerve fiber refractory to depolarization.

C. The low threshold sodium channels remain open, which increases the threshold of firing of action potential.

D. The efflux of sodium and influx of potassium due to operation of Na+, K+ ATPase oppose the depolarization

Which one of the following is correct?  

QUESTION ID:24

The heart rate shows variation during respiratory rhythm in most human subjects. Which one of the following statements describing the changes of heart rate during respiratory phases is true?  

QUESTION ID:25

Autotetraploids arise by the doubling of 2n complement to 4n. There are three different pairing possibilities at meiosis in tetraploids as given below:

A. Two bivalents

B. One quadrivalent

C. One univalent + one trivalent

Which of the above pairings can lead to production of diploid  

QUESTION ID:26

At 17 years, a 7 feet tall human was diagnosed with gigantism caused by pituitary tumor. The condition was surgically corrected by removal of the person's pituitary gland. Doctors advised hormonal therapy. The possible hormonal therapies that would be required for survival are

A. Thyroid hormone

B. Glucocarticoids

C. Glucagon

D. Growth hormone

E. Insulin

Which one of the following combination can be used?  

QUESTION ID:27

Given below are few statements with reference to blood clot formation which results from triggered chain of reactions:

A. Conversion of fibrinogen to fibrin.

B. Activation of factor XIII, which stabilizes fibrin mesh work.

C. Activation of factor XII, which promotes plasmin activation.

D. Enhancement of platelet aggregation.

Which one of the following of statements is correct with reference to roles of thrombin in hemostasis?  

QUESTION ID:28

The following is the amino acid sequence of a part of a protein encoded by gene 'X'. …..Phe Leu Val Pro Ser Tyr Cys….. A mutant for gene 'X' is isolated following treatment with a mutagen. The amino acid sequence of the same region encoded by the mutant gene is as follows: …..Phe Leu Phe Arg Arg lle….. Which of the following mutagens is most likely to have been used?  

QUESTION ID:29

Following four types of species were observed in a community: A. Species A has a large effect on community because of its abundance. B. Species B has a large role in community out of proportion to its abundance. C. Status of species C provides information on the overall health of an ecosystem D. Significant conservation resources are allocated to species D which is single, large and instantly recognizable. According to above description, species A, B, C and D are called respectively  

QUESTION ID:30

Complete the following hypothetical life table of a species to calculate the net reproductive rate Ro: The calculated Ro will be  

QUESTION ID:31

Which of the following is the correct decreasing order for the rate of decomposition of litter constituents?  

QUESTION ID:32

In Neurospora, the mutant stp exhibits erratic stop-andstart growth. When a female of sip strain is crossed with a normal strain acting as a male, all progeny individuals' showed stp mutant phenotype. However, the reciprocal cross resulted in all normal progeny, individuals. These results can be explained on the basis of

A. maternal inheritance

B. sex limited inheritance

C. sex influenced inheritance

D. stp mutation may be located In mitochondrial DNA

The most appropriate statement or combination of the above statements for explaining the experimental results is:  

QUESTION ID:33

A co-transduction experiment was performed to decipher the linear order of 4 genes: a, b, c and d. Three sets of experiments were done where transductants were selected for a (Set-1) or b (Set-2) or c (Set-3) and screened for cotransduction of the other markers. Based on the frequencies shown above, identify the most likely order in the genome.  

Based on the frequencies shown above, identify the most likely order in the genome.

QUESTION ID:34

A hypothetical biochemical pathway for the formation of eye color in insect is given below. Two autosomal recessive mutants 'a' and 'b' are identified which block the pathway as shown above. Considering that the mutants are not linked, what will be the phenotype of the F2 progeny if crosses were made between parents of the genotype aaBB x AAbb, and the F1 progeny are intercrossed?  

QUESTION ID:35

An analysis of four microsatellite markers was carried out in a family showing a genetic disorder. The results are summarized below Based on the above, which of the markers shows linkage to the disorder?  

QUESTION ID:36

In Group I are given 4 orders of class Insecta. Match each one with a common name (Group II) and its diagnostic characters (Group III) Group III (i) Elongate, membranous wings with netlike venation, abdomen long and slender, compound eyes occupy most of head, hemimetabolous metamorphosis (ii) Elongate chewing mouthparts, threadlike antennae, abdomen with unsegmented, forceps-like cerci, hemimetabolous metamorphosis (iii)Forewing long, narrow and leathery, hind wing broad and membranous, chewing mouthparts, hemimetabolous metamorphosis (iv) Elongate abdomen with two or three tail filaments, two pairs of membranous wings with many veins, forewings traiangular, short, bristle-like antennae, hemimetabolous metamorphosis (v) Adults with reduced mouthparts, elongate antennae, long cerci, nymphs aquatic with gills, hemimetabolous metamorphosis (vi) Wings membranous with few veins, well developed ovipositiors, sometimes modified into a sting, mouth parts modified for biting and lapping, holometabolous metamorphosis.  

QUESTION ID:37

Following are certain statements regarding C3, C4 and CAM plants?

A. The ratio of water loss to CO2 uptake is higher in CAM plants than it is in either C3 and C4 plants.

B. The rate of photosynthesis attains maximum rate at lower intracellular CO2 partial pressure in C4 plants than in C3 plants.

C. The compensation point in C3 plants are always lower than C4 plants.

D. Plants with C4metabolism need less rubisco than C3 plants to achieve a given rate of photosynthesis..

Which one of the following combinations of above statements is correct?  

QUESTION ID:38

Which of the following is a correct match of the animal with its attribute?  

QUESTION ID:39

Which of the following statements is NOT correct?  

QUESTION ID:40

Which of the following is a correct statement?  

QUESTION ID:41

The possible relationships between levels of disturbance and species diversity in a biological community are that species diversity

A. is unaffected by disturbance.

B. is highest at intermediate levels of disturbance.

C. decreases exponentially with increasing levels of disturbance.

D. starts decreasing only at higher levels of disturbance.

Match each graph with its corresponding statements above:  

QUESTION ID:42

In life history evolution there is generally a trade off between the size and number of offsprings produced. Some conditions are listed below:

A. Scarcity of food during the early stages of life

B. Provision of parental care

C. High mortality during early stages of life

D. Predator's preference for large sized prey

What are the above two conditions that would favour the production of a small number of large-sized offspring?  

QUESTION ID:43

Which of the following characteristics make Amborella the most basal living angiosperm?  

QUESTION ID:44

Following is a table showing selected characteristics of important fungal groups. In the above table, the fungal groups A, B, C and D, are, respectively,  

QUESTION ID:45

The diagram represents competition between species 1 and species 2 according to Lotka-Volterra model of competition. Given the conditions in the diagram, the predicted outcome of competition is  

QUESTION ID:46

Two kinds of natural selection (A and B) acting on a trait are shown in the figure below. In each, the top graph shows the trait frequency before and the bottom graph frequency after the action of natural selection. The kind of natural selection in A and B are  

QUESTION ID:47

A student was asked to design a knockout cassette for specifically deleting the p53 gene from the prostate gland of mice. Which one of the following pairs of cassettes will ensure deletion of the gene?

QUESTION ID:48

in a random sample of 400 individuals from a population with allele of trait in Hardy-Weinberg equilibrium, 36 individuals are homozygous for allele a. How many individuals in the sample are expected to carry atleast one allele A?  

QUESTION ID:49

Which of the following statements is NOT correct regarding effect of genetic drift?  

QUESTION ID:50

During the production of alcohol by fermentation using budding yeast, oxygen supply is kept 'limited. Why?

QUESTION ID:51

Which of the following is NOT a benefit for the female adopting polyandry?  

QUESTION ID:52

Individual A performs to another individual a behavioral act which has a fitness consequence. Match the behavioral acts (a to e) with the correct fitness consequence (i) to (iv) 

QUESTION ID:53

Assume that individual A wants to do an altruistic act to individual B and that benefit and cost of doing this act are, in ‘fitness’ units, 40 and 12, respectively. According Hamilton's Rule, A should perform the altruistic act only if B is his  

QUESTION ID:54

In an attempt to detect protein expression profile in a cell, Western blot technique is employed. Expression of two new proteins is to be followed by probing with respective high affinity antibodies (raised in rabbit). Unfortunately, the two proteins were found to co-migrate in SDS-PAGE profile. Under this situation, using one dimensional SDSPAGE and by Western blot, which one of the following is the best way to demonstrate the presence of both the proteins?  

QUESTION ID:55

Nichrome coated stainless steel electrodes were implanted in a rat brain for chronically recording the electrical activity of deep brain structures. During a study of 3 months the intensity of electrical signals gradually decreased. The following statements may explain the cause of this observation.

A. The deposition of metallic iron from the electrode tips caused degeneration of some neurons.

B. The gradual accumulation of microglia at the electrode tips increased the resistance of electrodes.

C. The neurons at the electrode tips were hyperpolarized gradually.

D. The threshold for firing action potential in the neurons at the electrode tips was increased due to prolonged presence of electrodes.

Which one of the following is correct?  

QUESTION ID:56

The number of seeds in the fruit of a plant species, Ho : μ=30. A random sample of 9 fruits gives the mean number of seeds as 24 with a standard deviation of 6.12.

(a) What are the confidence limits for the sample mean?
(b) Would your reject or accept the null hypothesis at 95% confidence level?

QUESTION ID:57

A chromatin iminuno precipitation (ChIP) assay was performed to determine specific transcription factor binding sites on the promoter of a gene. Pull down was done using either IgG or anti-bodies against c-myc. A DNA containing cmyc binding regions was used as a control for PCR amplification (input). Which one of the following PCR representations of DNA is correct?

QUESTION ID:58

Following are certain statements regarding somatic hybridization, a technique used for plant improvement.

A. Protoplasts of only sexually compatible plant species can be fused.

B. Hybrids are produced with variable and asymmetric amounts of genetic material of parental species

C. Protoplast fusion permits transfer of gene block or chromosomes.

D. Genes to be transferred need to be identified and isolated.

Which one of the following combinations of the above statements is correct?  

QUESTION ID:59

A researcher was repeating a FACS experiment but somehow got confused with the labeling of the tubes. There are four tubes, one control, C (with no fluorescent label), one standard 1, S1 (with FITC label), one standard 2, S2 (with PE label) and the last one test, T (which should be FITC positive). Given below is the result of the FACS experiment. What should be the correct labeling?  

QUESTION ID:60

Small molecular weight compounds affect the activity of luciferase differently. The oil/water solubility of various compounds is one property important for its effect on luciferase. The straight line in the graph was obtained by plotting the activity data with 50 different compounds. The luciferase activity of two new derivatives of Benzene (A and B) are shown below: Which of the following statements is correct?