Previous Year Questions

QUESTION ID:2

In a 30-residue peptide, the dihedral angles ϕ/ψ have been determined by one or more methods. When their values are examined in the Ramachandran plot, it is

QUESTION ID:3

In context to lac operon, if two bacterial strains P, and P2 with the genotypes O^CI⁺Z^- and O⁺I^-Z⁺ respectively, were used to produce mero-diploid daughter strain D, which one of the following statements correctly predicts the expression of Z gene (β-galactosidase activity) in all the three strains? (O⁺, I⁺ and Z⁺ denote the wild type allele of the respective genes).

QUESTION ID:4

In the accompanying figure, reaction kinetics of three proteins (a, b, c) is presented. Protein concentrations used to obtain this data are a - 1 mg/ml; b- 4 mg/ml; c - 2 mg/ml.If catalytic efficiency is defined as Kcat/Km, which of the following statements is correct?

QUESTION ID:5

The 3'end of most eukaryotic mRNAs is defined by the addition of a polyA tail- a processing reaction called polyadenylation. The addition of poly A tail is carried out by the enzyme Poly(A) Polymerase. Given below are few statements about this process:

A. Poly(A) Polymerase is a template independent enzyme.

B. Poly(A) Polymerase catalyses the addition of AMP from dATP to the 3' end of mRNA.

C. Poly(A) Polymerase is a RNA-template dependent enzyme

D. Poly(A) Polymerase catalyzes the addition of ADP from ATP to the 3' end of mRNA.

E. Poly (A) Polymerase catalyzes the addition of AMP from ATP to the 3' end of mRNA.

F. Poly (A) Polymerase catalyzes the addition of AMP from dADP to the 3' end of mRNA.

Which of the following combination is true?

QUESTION ID:6

In order to study the transcription factor TFIIH, it was cloned from a large number of human subjects. Surprisingly, the subjects having mutation in TFIIH, also showed defects in their DNA repair system. Given below are the explanations:

A. DNA damage is always associated with transcription inhibition

B. TFIIH has no role in DNA repair.

C. In mammalian system, TFIIH plays an active role in transcription coupled. DNA repair process

D. Because of mutation in TFIIH, transcription initiation is inhibited and incompletely synthesized mRNAs remain attached to the template DNA leading to DNA damage.

Choose the correct answer.

QUESTION ID:7

With an intention to identify the -genes expressed in an organism at specific stage of development, mRNAs were isolated from the given organism, cDNAs were synthesized, Cloned in a suitable vector and sequenced.

A few of the cDNA sequences showed no matches with the genomic DNA sequence. Further, it was observed that these sequences were U-rich and found to be in stretches dispersed along the sequence. The following may be possible reasons for appearance of such RNA:A. Splicing

B. Alternate splicing

C. Trans-Splicing

D. Guide RNA mediated introduction of Us involving endonuclease, terminal-U-transferase and RNA ligase

E. Deaminations converting C to U

Which of the following is the most appropriate reasons?

QUESTION ID:8

A patient with breast cancer was given a dose of radiation along with chemotherapy and was apparently cured of the tumor. After five years, a tumor was noticed in the patient's lungs, but the doctors confirmed that it was derived from cells of the mammary gland.,. The following possibilities were suggested by the doctor.

A. Bacterial infection, after radiation, led to development of the tumors in the lungs.

B. Migration of residual chemo-resistant cells from the mammary gland resulted in tumors in the lungs

C. Epithelial-to-mesenchymal transition had occurred in the lungs.

D. Cells in the lungs were induced to become a tumor after chemotherapy and from factors secreted by mammary cells

:Which of the following is correct?

QUESTION ID:9

Certain chemokines are known to suppress HIV infection whereas proinflammatory cytokines are known to enhance infection. In order to explain these findings, control and chemokine repeptor knock-out animals were treated with pro inflammatory cytokines followed by HIV administration and then infection was assessed periodically. Which one of the graphical representation given below best explain the experimental results.

QUESTION ID:10

Following are certain statements regarding seed development in plants:

A. During final phase of development embryo's of "orthodox" seeds became tolerant to desiccation, dehydrate losing up to 90% of water

B. Dormant seeds will germinate upon rehydration while quiescent seeds require additional treatments or signals for the germination

C. Precocious germination is germination of seeds without passing through the normal quiescent and/or dormant stage of development

D. Abscisic acid is known to inhibit precocious germination

Which one of the following combinations is correct?

QUESTION ID:11

When one isolates ribosomes from bacterial lysate, apart from 70S, 50S and 308 ribosomal subunits, one also finds a small population of 100S, 130S and 150S sub-units. EDTA dissociates these larger ribosomal subunits into 50S and 30S, suggesting that they have both the subunits. Upon addition of cations they reassociate into 70S, but none of the other forms could be detected. What is the reason for not obtaining the >70S forms?

QUESTION ID:12

Development of vulva in C. elegans is initiated by the induction of a small number of cells by short range signals from a single inducing cell. With reference to this, following statements were put forwar9

A. When the anchor cell was ablated early in development no vulva formed.

B. In a dominant negative mutant of let-23, a primary vulva formed but the secondary vulva formation did not take place.C. A cell adopting a primary fate inhibits adjacent cells from adopting the same fate by lateral inhibition involving LIN-39 and also induces the secondary fate in these cells.

D. A constitutive signal from the hypodermis inhibits the development of both the primary and secondary fates but it is overruled by the initial signal from the anchor cell.

Which of the above statements is true?

QUESTION ID:13

A cross was made between Hfr met+ arg+ leu+ strS X F- met- arg- leu- strr in which leu+ exconjugants are selected. If the linear organization of the genes are leu+ arg+ met+, which one of the following genotypes is expected to occur in the lowest frequency?

QUESTION ID:14

A researcher was studying a protein 'X' which has been observed to move across cells when an extracellular electrical stimulus is provided. An artificial peptide 'P' was prepared which resembles the structure of connexins and competitively inhibits connexon formation. Which one of the following statements will best explain the fate of protein 'X' if the cells are treated with peptide 'P' and then electrical stimufus is provided.

QUESTION ID:15

Symbiotic nitrogen fixation. in legume nodules involves complex interaction between Rhizobium and legume roots. This complex interaction is governed by

A. Integration of sym plasmid of Rhizobium in the root nuclear genome.

B. Sensing of plant flavonoids by rhizobia.

C. Activation of nod genes in rhizobia.

D. Activation of NODULIN genes in legume roots.

Which one of the following combinations is correct?

QUESTION ID:16

What will happen if wingless RNAi is expressed in wingless expressing cells from the stage when this gene initiates its expression in a developing Drosophila embryo?

A: The enhanced expression of wingless thus caused will broaden the area of engrailed expression.

B. Since wingless protein makes a long range gradient, its effect will not be seen in the same segment.

C. The posterior compartment of each future segment will get affected.

D. Since engrailed expression is initiated by pair rule genes, the posterior segment will not be affected.

Which one of the following will most appropriately answer the question?

QUESTION ID:17

Which one of the following about development of sea urchin embryos is TRUE?

QUESTION ID:18

Which one of the following is the correct combination?

QUESTION ID:19

Formation of digits and sculpting the tetrapod limb requires death of specific cells in the limb in a programmed manner. Which one of the followinginteractions could explain proper limb formation?

QUESTION ID:20

Of the following signaling processes which one is NOT involved in cellular movement or cytoskeletal changes?

QUESTION ID:21

There are three substances A, B and C. Given below are the pattern of immunological responses in rabbits when(i) A is administered along with C,(ii) B is administered along with C and(iii) A is conjugated with B and administered along with C.Which one of the following is the correct identification?

QUESTION ID:22

Light is an important factor for plant growth and development. There are several photoreceptors in higher plants such as Arabidopsis thaliana involved in perception of various wavelengths of light. Some statements are given below related to photoreceptors:

A. Red light photoreceptors are represented by a gene family.

B. Phytochrome C is the most prominent photoreceptor to perceive red light

C. Cryptochrome 1 and cryptochrome 2 have evolved from bacterial DNA photolyases.

D. Far-red light is perceived by phytochrome D.

Which one of the following combinations of abovestatements is correct?

QUESTION ID:23

Chromatin condensation is driven by protein complexes, called condensins which are members of a family of "structural maintenance of chromatin" (SMC) proteins that play a key role in the organization of eukaryotic chromosomes. Condensins along with another family of SMC proteins called cohesins significantly contribute to chromosome segregation during mitosis. If the cells are treated with an inhibitor of cdk 1 phosphorylation immediately before. the cells. enter M phase, which of the. following statements is most likely to be true? 

QUESTION ID:24

Two homozygous individuals (P1 and P2), were genotyped using dominant DNA markers A and B, as shown below. The F1 progeny obtained was test crossed and frequency of progeny with which different genotypes appear, is given below: The following conclusions were made:

A. In the F1 markers A and B are linked and in coupling phase (cis)

B. In the F1 markers A and B are linked and in repulsion phase (trans)

C. The distance between A and B is 10 cM

D. The distance between A and a is 5 cM

Which of the above conclusions are correct? 

QUESTION ID:25

The above pedigree shows the inheritance of a rare allele. The allele is:

QUESTION ID:26

Pyruvate dehydrogenase is subject to feed back inhibition by its products in glycolysis. Some of the chemical compounds which might be involved in the process, are listed below:

A. NADH

B. FADH

C. Acetyl-CoA

D. Acetaldehyde

Which one of the following combinations of above chemical compounds is involved in feedback inhibition of pyruvate dehydrogenase? 

QUESTION ID:27

Carbohydrates synthesized by photo-synthesis are converted into sucrose and transported via phloem to other parts of the plant. The following aspects are associated with sucrose uploading in phloem and its transport:

A. Both reducing and non-reducing sugars are transported efficiently through phloem.

B. Sucrose uploading can be both symplastic and apoplastic.

C. The route of phloem uploading is- mesophyll cells phloem parenchyma  companion cells  sieve tubes.

D. Transport in sieve tubes is as per the 'pressure-flow model'.

Which one of the following combinations is correct?

QUESTION ID:28

A 'Z' scheme describes electron transport in O2-evolvingphotosynthetic organisms. The direction of electron flow is presented in the following sequences:

A. P680* → Pheophytin→ Q_A→Q_B → P_C Cytochrome b_of→ P700

B. P700* → Phylloquinone →  FeS_A→ FeS,→ FeS, →Fd

C. P680*→ Pheophytin → Q_A→Q_B →  Cytochrome b_of→ Pc→ P700

D. P700*→ Phylloquinone →FeS, → FeS_A FeS, →Fd

Which one of the following combinations is correct? Question Type: 

QUESTION ID:29

A plant with red fruit is crossed to a plant with white fruit. The F1 progeny had red fruits. On selfing the F1 two kinds of progeny were observed, plants with red fruits and those with white fruits. To test whether it was a case of recessive epistatic interactions a chi-square test was performed. A value of 1.062 was obtained (chi-square value of P0.05=3.841 for Degree of freedom=1). The following statements were made:

A. The null hypothesis was that plant with red and white fruits will occur in a 9:7 ratio

B. The null hypothesis was that plant with red and white fruits will occur in a 1:1 ratio

C. Based on the chi square value, it is a case of recessive epistatic interactions

D. Based on the chi square value, it is not a case of recessive epistatic interactions

Which of the combination of above statements is correct?

QUESTION ID:30

During physical exercise, the oxygen supply to the active muscles is increased which has been explained by the following statements:

A. PO2 declines and PCO2 rises in the active muscles

B. The temperature is increased and pH is decreased in active muscles

C. 2, 3-biphosphoglycerate is decreased in RBC and PO2 rises

D. Metabolites accumulating in the active muscles increase the affinity of hemoglobin to oxygen

Which one of the following is NOT correct?

QUESTION ID:31

Somatic recombination was caused by mild exposure to radiation on flies heterozygous for a given allele during specific stages of development and the individuals were allowed to develop. Such individuals are likely to have

A. clones of homozygous cells in heterozygous body.

B. site specific mutagenesis.

C. twin spots, i.e., patches of mutants cells and homozygous wild type cells in heterozygous body

D. tissue specific expression of the given allele.

Which of the following combination of answers will be most appropriate?

QUESTION ID:32

The fractional clearance of neutral and cationic dextran molecules of various sizes through kidneys of a rat is shown in the figures below. Which one of the following is correct?

QUESTION ID:33

Following are certain statements related to plants exposed to dehydration stress:

A. When the water potential of the rhizosphere decreases due to water deficit, plants continue to absorb water as long as plant water potential islower than that of soil water.

B. The ratio of root to shoot growth, increases in response to water deficit

C. Plant cells tend to release solutes to lower water potential during periods of osmotic stress. .

D. Abscisic acid is synthesized at higher rate when leaves are dehydrated, and more ABA accumulates in the leaf apoplast.

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

QUESTION ID:34

Which one of the following is the most appropriate match for the protected areas of India?

QUESTION ID:35

Estradiol synthesis follows a 2 cell-2- gonadotropin theory, where partial synthesis occurs in the granulosa cells and the rest in the thecainterna cells of the Graafian follicle. Which of the following correctly represents estradiol synthesis and secretion?

QUESTION ID:36

Sickle cell anemia is a recessive genetic disease caused due to a point mutation in the 6th codon abolishing one of the MspII endonuclease digestion site present in the β-globin gene. MspII digested DNA from a normal person gives two bands, 1150 bp and 200 bp, in β-globin gene. A family with a proband (based on the disease phenotype) gave the following MspII digestion pattern:The following conclusions were drawn:

A. Son (I) is the proband and the given mutation is not present in Son (II).

B. The daughter is a carrier for the given mutation.

C. The gene is X-linked and thus Son (I), becomes the proband.

D. The father and daughter are affected

E. A de novo mutation in same site on normal allele has allowed appearance of diseased phenotype in the probandWhich of the following combination of conclusions wilt be the most appropriate for the figure given above?

QUESTION ID:37

The mechanism of sound localization in a 'horizontal plane' by the human" auditory system can be explained by

A. the difference in time between the arrival of stimulus in two ears

B. the difference in phase of the sound waves on two ears

C. the difference in tuning curves of two auditory nerves

D. the activity of neurons in superior olivary nucleus, but not by the neuronal activity of auditory cortex

Which one of the following is NOT correct?

QUESTION ID:38

The following table shows selected characters used in analyzing the phylogenetic relationships of four plant taxa:Taxa T1, T2, T3 and T4 are respectively:

QUESTION ID:39

In high altitude, hypoxia induces increased number of circulating red blood cells, which can be explained by the following changes:

A. The transcription factors, HIPs are produced.

B. Erythropoietin secretion is increased

C. Myoglobin content is decreased

D. Cytochrome oxidase is decreased

Which one of following is NOT true?

QUESTION ID:40

Given below are the characteristics of a few mammalian order. Match the names of the animals with the characteristics of their orders:

A. Hooves with even number of toes on each foot, omnivorous

B. Teeth consisting of many thin tubes cemented together, eats ants and termites

C. Opposable thumbs, forward facing eyes, well developed cerebral cortex, omnivorous.

D. Hooves with an add number of toes on each foot; herbivorous

(i) Tapir

(ii) Lemur

(iii) Aardvark

(iv) PigChoose

the correct combination

QUESTION ID:41

Which of the following is true about the Digestion Efficiency (DE)-(assimilation/consumption) and Ecological Efficiency (EE (production/consumption) of ectotherms and endotherms?

QUESTION ID:42

Given below is a matrix of possible interactions beneficial. (+), harmful (-), Neutral (0) between species 1 and 2. The names of interactions, A, B, Cand D, respectively; are

QUESTION ID:43

Which of the following is/are NOT valid explanation(s) for the observed pattern of species richness?

A. Older communities are more species rich.

B. Large areas support more species.

C. Natural enemies promote reduced species richness at local level.

D. Communities in climatically similar habitats may themselves be similar in species richness.

E. Greater productivity permits existence of more species.

QUESTION ID:44

Two lakes (I and II) with a similar trophic structure of phytoplankton-zooplankton, planktivorous fish food chain were chosen. To understand the 'top-down' effects, some piscivorous fish (those that feed on planktivorous fish) were introduced into Lake I, making it a system with four trophic levels. Lake II was enriched by adding large quantities of nitrates and phosphates to study the 'bottom-up' effects over a period of time. Changes in the biomasses of each trophic level were measuredThe expected major changes in the two lakes are 

QUESTION ID:45

The following table shows the number of individuals of each species found in two communities: (Hint: In values for 0.05, 0.10, 0.25 and 0.80 are -3.0, -2.3, -1.4 and -0.2, respectively) The calculated Shannon diversity index (H) values for communities C1 and C2, respectively are 

QUESTION ID:46

In a population at Hardy-Weinberg equilibrium, the genotype frequencies are: f(A1A1)= 0.59; f(A1A2) = 0.16; f(A2A2) = 0.25. What are the frequencies of the two alleles at this locus? 

QUESTION ID:47

Following are the main types of defense employed by prey species against predators Types of defense: Chemical with aposematic coloration

(A); Cryptic coloration

(B); Batesian mimicry

(C); Intimidation display

(D) Prey Species: Grasshoppers and seahorses

(i); Hoverflies and wasps (ii); Bombardier beetles, ladybird beetles, many butterflies (iii); Frilled lizard, Porcupine fish (iv)

Which one of the following combinations is correct? 

QUESTION ID:48

In the evolutionary tree given below terms A, B, C, D and E represent respectively

QUESTION ID:49

Which of the following options match the plant tissue type with its correct function in vascular plants? 

QUESTION ID:50

Following is the list of some important events in the history of life and the names of the epochs of Cenozoic era.Events

A. Angiosperm dominance increases; continue radiation of most present day mammalian orders

B. Major radiation of mammals, birds and pollinating insects

C. Origins of many primate groups

D. Origin of genus Homo

E. Appearance of bipedal human ancestors

F. Continued radiation of mammals and angiosperms, earliest direct human ancestors Epochs I

(i)Paleocene (ii) Pleistocene (iii) Oligocene (iv) Pliocene (v) Eocene (vi) Miocene

Which one of the following is the correct match of events with the epochs?

QUESTION ID:51

Which of the following gives the correct human disease- causal microbe match for each?

QUESTION ID:52

Match the five (A -E) group of organisms with their correct' taxonomic rank (i - v) given below:

QUESTION ID:53

Compared to K-selection, r-selection favours

QUESTION ID:54

Homing pigeons, when released at a place far away from their home, use earth's magnetic field or the sun as navigational cues and choose the right direction to fly. To test the hypotheses, two experiments were conducted. In Experiment I, one group of pigeons (Test) were equipped with Helmholtz coils (which disrupt magnetic field detection), while the second group (Control) were not. Both groups were released on a sunny day. Experiment II used the same Control and Test groups of pigeons, but they were released on a cloudy, overcast day. The expected results, if the hypotheses is true, would be

QUESTION ID:55

Brothers A and B have the same father but different mothers. B wants A to help him, which involves both benefits (b) and costs (c) for A. If A incurs a cost of 30 'Darwinian fitness units' in that act, under what condition, should he help B, following Hamilton’s rule?

QUESTION ID:56

A protein undergoes post-translational modifications. In an experiment to identify the nature of modifications, the following experimental results were obtained.

A. Protein moved more slowly in an SDS PAGE.

B. Isoelectric focusing (IEF) showed that there was no change in the pI.

C. Mass spectrometric analysis showed that the modification was on serineThe modification that the protein undergoes is likely to be

QUESTION ID:57

In transgenic mice, the orientation an location of the loxP sites determine whether Cre recombinase induces a deletion, an inversion or a chromosomal translocation. If a researcher wants to put loxP sites in such a manner that only inversion will take place, which one of the following construct best justifies their intension. Gene X is the target gene.

QUESTION ID:58

For the aquaculture farming of Indian major carps several techniques are used. Which one of the following is NOT used for this purpose:

QUESTION ID:59

A gene from genomic library is screened by using hybridization technique. After hybridizing the probe, usually a stringent washing step is given. The following statements are given to explain the stringent washing step:

A. Stringent washing takes care of removing unincorporated and non-specifically hybridized probe molecules

B. Stringent washing is done in solution having high salt concentration and lower temperature

C. Stringent washing is done in solution having low salt concentration keeping higher temperature

D. Salt present in washing solution supports hybrids to stay intact by shielding the interference of water molecules

E. Salt reacts with DNA molecules and allows easy dissociation of hybrids

F. Stability of hybrid is directly proportional to the temperature

Which combination of the above statements is most appropriate for stringent washing, step?

QUESTION ID:60

In a confirmatory test for HIV, one or more viral antigens are detected in the blood of patients. Following are the steps to be performed for the experiment:

A. Transfer of viral antigens to nitrocellulose paper

B. Incubation with the buffer containing antibodies specific for viral antigens.

C. Separation of viral antigens by SDS-PAGE

D. Detection of bands by enzyme-linked secondary antibody Identify the correct sequence steps to be performed for the experiment.

QUESTION ID:61

In response to a drug, changes in protein levels were examined in a cell line. A pulse chase experiment was performed using 35S labeled methionine. In comparison, to untreated samples, the following observations were made: few minutes after stimulation, protein X accumulates and this was followed by reduction in protein Y and Z. The correct interpretation of these observations would be:

QUESTION ID:62

A student while constructing knock-out mice isolated mouse embryonic, stem cells and introduced an engineered DNA into the cells. However, none of the mice were transgenic. On checking the cells containing DNA construct, he found that he had made a mistake in constructing the DNA since the cells were resistant to gancyclovir but sensitive to G418. Which one of the following constructs had he

QUESTION ID:63

The most important property of any microscope is its resolution (D) and can be calculated from the formulaD= 0.61λ/ N sinαwhere D is, minimum distance between two distinguishable objects,A. is the wave length of incident light, a is, the angular aperture and N is the refractive index of the medium. Given below are several suggestions to improve the resolution of a microscope:

A. decrease the wave length of incident light

B. increase the wave length of incident light

C. use oil which has a higher refractive index

D. use oil because of its lower refractive index

Which one is the correct suggestion?

QUESTION ID:64

The mean and standard deviation of serum cholesterol in a population of senior citizens are assumed to be 200 and 24mg/dl, respectively. In a random sample of 36 senior citizens, what values of cholesterol (to the nearest whole number) should lead to rejection of the null hypothesis at 95% confidence level?

QUESTION ID:65

The following genes have been genetically engineered to develop herbicide resistance in plants:

A. Resistance to glyphosate using the 5-enolpyruvyl shikimate-3-phosphate synthase gene

B. Bialaphos resistance using the bar gene

C Sulfonyl urea resistance using the acetolactate synthase gene

D. Atrazine resistance using the glutathione S-transferase gene .

In which of the above two cases the mechanism is based on abolition of herbicide binding to the enzyme?

QUESTION ID:66

Somatic embryogenesis is an important exercise in micropropagation and genetic engineering of plants. The following steps are considered as critical for achieving somatic embryogenesis:

A. Reducing the concentration of sucrose in the medium by half.

B. Addition of the hormone, 2, 4-dichlorophenoxyacetic acid to induce somatic embryos.

C. Reduce agar concentration to 0.6% (w/v)

D. Use maltose in place of sucrose as a carbon source

Which one of the following combinations is correct?

QUESTION ID:67

Factor IX is essential for blood clotting. Deficiency of Factor IX could be corrected by delivering factor IX gene using viral vectors. In an experiment the gene for Factor IX was cloned appropriately into Adenovirus (AV), Adeno-associated virus (AAV) and Retrovirus (RV). Retrovirus integrate the gene into the dividing cells. AAV integrates partially into non-dividing cells. AV does not integrate the gene but transfects both dividing and non-dividing cells.

Following expression profile for Factor IX was observed when the three vectors were injected' intra-muscularly into three groups of experimental mice. Which one of the following outcomes is correct?