Previous Year Questions

QUESTION ID:2

Polysome profiling of cells treated with three hypothetical translation inhibitors is shown in the plot below. These three inhibitors are

(i) CHP – leaky inhibitor of translation

(ii) LTM – arrests ribosomes at the initiation codon

(iii) PTM – inhibits ribosome scanningMatch the polysome profile to the inhibitor

QUESTION ID:3

In mammals CG rich sequences are usually methylated at C, which is a way for making genes for silencing. Although the promoters of housekeeping genes are often associated with CpG islands yet they are expressed in mammals. Which one of the following best explains it?

QUESTION ID:4

In an experiment, red blood cells were subjected to lysis and any unbroken cells were removed by centrifugation at 600g. The supernatant was taken and centrifuged at 100,000g, the pellet was extracted with 5M NaCl and again centrifused at 100,000g. Which of the following protein will be present in supernatant?

QUESTION ID:5

In order to study intracellular trafficking of protein ‘A’, it was tagged with GFP (A-GFP). Fluorescence microscopy showed that A-GFP co-localizes with LAMP1. In the presence of bafilomycin A, an inhibitor of H+- ATPase, A-GFP does not co-localize with LAMP1. Instead, it localizes with LC3 puncta. Which one of the following statements is true?

QUESTION ID:6

In animals, four separates families of cell – cell adhesion proteins are listed in Column A and their functional characteristics are given in Column BWhich one of the following is the correct combination?

QUESTION ID:7

A student treated cancer cells with an anticancer drug and perform western blot analysis. Which one of the following blots is the best representation under the control (C) and treated (T) samples? (3)

QUESTION ID:8

In Trypanosomes, a 35 base leader sequence is joined with several different transcripts making functional mRNAs. The leader sequence is joined with the other RNAs by

QUESTION ID:9

Following are the list of the pathogens (column A) and the unique mechanisms they employ for invading the immune response (column B).Which of the following is the correct match between the organism and their respective mechanism to evade immune response?

QUESTION ID:10

Two steroid hormone receptors X and Y both contain a ligand binding domain. Using recombinant DNA technology, a modified hybrid receptor H is prepared such that it contains the ligand binding domain of X and DNA binding domain of Y. three sets of cells overexpressing receptors X, Y and H were then treated separately either with hormone X or with hormone Y. assuming that there is no cross– reactivity, which one of the following graphs best represent the receptor – ligand binding in each case?

QUESTION ID:11

A protein X is kept inactive state in cytosol as complexed with protein Y. Under certain stress stimuli, Y gets phosphorylated resulting in its proteasomal degradation. X becomes free, translocates to the nucleus and results in the transcription of a gene which causes cell death byapoptosis. Stress stimuli were given to the following four different cases

Case A: Protein Y has a mutation such that phosphorylation leading to proteasomal degradation does not occur.

Case B: Cells are transfected with a gene which encodes for a protein L that inhibits the translocation of protein Y to the nucleus.

Case C: Cells are transfected only with a empty vector used to transfect the gene for protein L

Case D: Cells are treated with Z-VAD–FMK, a broad spectrum caspase inhibitor. Which of the following graphs best describes the apoptotic state of the cells in the above cases?

Y-axis represents % apoptotic cells.

QUESTION ID:12

Consider the following events which occur during fertilization of sea urchin eggs.

A. Resact/Speract are peptides released from the egg jelly and help in sperm attraction.

B. Bindin, an acrosomal protein interacts in a species specific manner, with eggs.

C. A “respiratory burst” occurs during cross-linking of the fertilization envelope, where a calcium- dependent increase in oxygen level is observed.

D. IP3, which is formed at site of sperm entry, sequesters calcium leading to cortical granule exocytosis.

Which of the above statement(s) is NOT true?

QUESTION ID:13

Following statement were given regarding decisions taken during development of mammalian embryos

A. Pluripotency of inner cell mass is maintain by a core of three transcription factors, Oct 4, Sox 2 and nanog.

B. Prior to blastocyst formation each blastomere expresses both Cdx 2 and the Oct 4 transcription factors and appears to be capable of becoming either ICM or trophoblast .

C. Both ICM and trophoblast cells synthesize transcription factors Cdx 2.

D. Oct4 activates Cdx2 expression enabling some cells to become trophoblast and other cells to become ICM.

Which of the above statement are true?

QUESTION ID:14

Apoptosis during early development is essential for proper formation of different structures. In C. elegans, apoptosis is accentuated by ced-3 and ced-4 genes, which in turn are negatively regulated by ced-9 and eventually Egl-1. When compared to mammals, functionally similar homolog has been identified. Accordingly, which one of the following statements is NOT correct?

QUESTION ID:15

Which one of the following statements regarding B cell receptor (BCR) and T cell receptor (TCR) is not true?

QUESTION ID:16

In case amphibians, the dorsal cells and their derivatives are called as “Spemann – Mangold organizer”. Following statements are related to the “organizer” were made:

A. It induces the host’s ventral tissues to change their fates to form neural tube and dorsal mesodermal tissues.

B. It cannot organize the host and donor tissues into a secondary embryo.

C. It does not have the ability to self-differentiate into dorsal mesoderm

D. It has ability to initiate the movements of gastrulation.

E. Both β-catenin and Chordin are produced by the organizer

Which of the above statements are correct?

QUESTION ID:17

Driesch performed famous “pressure plate” experiments involving intricate recombination with 8-celled Sea urchin embryo. This procedure reshuffled the nuclei that normally would have been in the region destined to form endoderm into the presumptive ectoderm region. If segregation of nuclear determinants had occurred, resulting embryo should have been disordered. However, Driesch obtained normal larvae form these embryospossible interpretations regarding the 8-celled sea urchin embryo are:

A. The prospective potency of an isolated blastomere is greater than its actual prospective fate

B. The prospective potency and prospective fate of blastomere were identical

C. Sea-urchin embryo is a “harmoniously equipotential system” because all of its potentially independent parts interacted together to form single embryo.

D. Regulative development occurs where location of a cell in the embryo determines its fate.

Which of the interpretation(s) is/are true?

QUESTION ID:18

Read the following statements related to plant pathogen interaction

A. Systemic acquired resistance is observed following infection by compatible pathogen

B. Induce systemic resistance is activated following infection by compatible pathogen

C. A bacterial infection can induce effector triggered immunity (ETI) leading to hypersensitive response locally

D. NPR1 monomers that are released in cytosol due to salicylic acid accumulation is rapidly translocated to nucleus

Which combination of above statements is correct?

QUESTION ID:19

Given below are statements describing various features of solute transport and photoassimilate translocation in plants:

A. Apoplastic phloem loading of sucrose happens between cells with no plasmodesmatal connections.

B. Growing vegetative sinks (e.g. young leaves and roots) usually undergo symplastic phloem unloading

C. Movement of water between the phloem and xylem occurs only at the source and sink regions

D. Symplastic loading of sugars into the phloem occurs in the absences of plasmodesmatal connections

Select the option that gives combination of correct statements:

QUESTION ID:20

 Given below are names of phytohormones in column I and their associated features/effects/function in column II.Select the correct set of combinations from the options given below;

QUESTION ID:21

If in a blood transfusion, type A donor blood is given to recipient having type B blood, the red blood cells (RBC) of donor blood would agglutinate but the recipients RBCs would be least affected. These observations can be explained in the following statements.

A. Agglutininins in recipient’s plasma caused agglutination by binding with type Aagglutinogens.

B. The agglutinins of donor blood was diluted in recipient’s plasma resulting in low agglutination.

C. Low titre of anti-A agglutinins is the cause of low agglutinations of recipients RBC’s.

D. High agglutination of donor RBC’s is the outcome high titre of anti-B agglutinins

Which of the above statement(s) is/are INCORRECT?

QUESTION ID:22

The arterial pressure usually raises and falls 4 to 6 mm Hg in a wave like manner causing “respiratory waves”. The probable mechanism of these waves has been proposed in the following statements:

A. The more negative intrathoracic pressure during inspiration reduces the quantity of blood returning to the left side of the heart causing decreased cardiac output.

B. The changes of intrathoracic pressure during respiration can excite vascular and atrial stretch receptors which affect heart and blood vessels.

C. The activity of medullary respiratory centers can influence the vasomotor center.

D. The “respiratory waves” are outcome of the oscillation of the central nervous system ischemic pressure control mechanism.

Which of the above statement(s) is/are NOT appropriate?

QUESTION ID:23

The uptake of nitrous oxide (N2O) and carbon monoxide (CO) in the blood of lung alveolar capillary relative to their partial pressure and the transit time of red blood cell in capillary is shown in the figure below:The reason for difference in the pattern of alveolar gas exchange of N2O and CO have been proposed in the following statements:A. N2O does not chemically combine with proteins in blood but equilibrate rapidly between alveolar gas and blood.B. CO has high solubility in the bloodC. CO has high solubility in the alveolar capillary membrane.D. The dispersion of N2O between alveolar gas and blood is considered as diffusion limited.Which of the above statement(s) is/are INCORRECT?

QUESTION ID:24

Individual and overlapping expression of homoeotic genes in adjacent whorls of a flower determine the pattern of floral organ development. In an Arabidopsis mutant, floral organs are distributed as follows:Whorl 1 (outer most) – carpelWhorl 2 – stamensWhorl 3 - stamensWhorl 4 (inner most) – carpelLoss of function mutation in which one of the following genes would have caused the above pattern of floral organ development?

QUESTION ID:25

In photosynthetic electron transport, electrons travel through carriers organized in the “Z-scheme”. The following are indicated as directions of electron flow:

A. P680 → PQA→ PQB→Cytb6f → Pheo →PC→ P700

B. P700 → A0→A1→FeSx→FeSA→FeSB→Fd

C. P680→Pheo→PQA→ PQB→Cytb6f →PC →P700

D. P700 →A1→A0→FeSB→FeSA→FeSX→Fd

Which of the following combinations is correct?

QUESTION ID:26

Phytochrome-mediated control of photomorphogenesis is linked to many other gene functions. The following statements are made on the mechanism of phytochrome action:

A. Phytochrome function requires COP1, an E3 ubiquitin ligase that brings about protein degradation.

B. COP1 is slowly exported from the nucleus to the cytoplasm in the presence of light.

C. HY5 is targeted by COP1 for degradation in the presence of light.

D. HY5 is a transcription factor involved in photomorphogenetic response.

Which of the following combinations is correct?

QUESTION ID:27

The C4 carbon cycle is a CO2 concentrating mechanism evolved to reduce photorespiration. The following are stated as important features of the C4 pathway:

A. The leaves of C4 plants have Kranz anatomy that distinguishes mesophyll and bundle sheath cells.

B. In the peripheral mesophyll cells, atmospheric CO2 is fixed by phosphoenol pyruvate carboxylase yielding a four-carbon acid.

C. In the inner layer of mesophyll, NAD-malic enzyme decarboxylates four-carbon acid and releases CO2.

D. CO2 is again re-fixed through Calvin cycle in the bundle sheath cells.

Which one of the following combinations is correct?

QUESTION ID:28

External pressure given on a mixed nerve causes loss of touch sensation while pain sensation remains relatively intact. On the other hand, application of local anesthetics on the same nerve, induces loss of pain sensation keeping touch sensation least affected. These observations can be explained by the following statements:

A. External pressure causes loss of conduction of impulses in small diameter sensory nerve fibres.

B. Local anesthetics depress the conduction of impulses in large diameter sensory nerve fibres.

C. Touch-induced impulses are carried by fibre Type A

D. Fibre type C is responsible for pain sensation

Which of the above statement(s) is/are INCORRECT?

QUESTION ID:29

The probable effects of lesion of left optic tract on the vision of a human subject are given below. Identify the correct statement.

QUESTION ID:30

Inversions are considered as cross-over suppressors because:

QUESTION ID:31

Three met- E. coli mutant strains were isolated. To study the nature of mutation these mutant strains were treated with mutagens EMS or proflavins and scored for revertants. The results obtained are summarized below:(+ stands for revertants of the original mutants and – stands for no revertants obtained).Based on the above and the typical mutagenic effects of EMS and proflavin, what was the nature of the original mutation in each strain?

QUESTION ID:32

The following pedigree shows the inheritance pattern of a trait.From the following select the possible mode of inheritance and the probability that the daughter in generation III will show the trait.

QUESTION ID:33

A pair of alleles govern seed size in a crop plant. ‘B’ allele responsible for bold seed is dominant over ‘b’ allele controlling small seed. An experiment was carried out to test if an identified dominant DNA marker (5kb band) is linked to alleles controlling seed size. A plant heterozygous for the marker and the alleles was crossed to a small seeded plant lacking the 5kb band. 100 progeny obtained from the cross were analysed for the presence and absence of the DNA marker. The result are tabulated below: Based on the above observations which one of the following conclusions is correct?

QUESTION ID:34

The following diagram represents steroidogenic pathway in the Zona Glomerulosa of the adrenal cortex:What do A, B and C represents, respectively?

QUESTION ID:35

The following scheme represents deletions (1-4) in the rII locus of phage T4 from a common reference point:Based on the above the predicted order of the point mutations is:

Four point mutations (a to d) are tested against four deletions for their ability (+) or inability (-) to give wild type (rII+) recombinants. The results are summarized below:

Based on the above the predicted order of the point mutations is

QUESTION ID:36

Following are the plots representing biological rhythms at different time points depicted as: SR = Sunrise ; N= Noon ; SS = Sunset ; MN = MidnightWhich of the plot(s) represents the ultradian biological rhythm(s)?

QUESTION ID:37

The Population of the Non-poisonous butterflies have the same the color pattern as some highly poisonous butterflies. Assume that the population of non-poisonous butterflies is higher than the poisonous butterflies. Given this, what will be the impact of this mimicry on the fitness of the population of the poisonous butterflies in the presence of the predator?

QUESTION ID:38

The given below is the graphical representation of the changes in morphological features over a period of the geological time scale, where population A accumulates heritable morphological features and give rise to distinct species B. Population B splits in to a distinct species B2Which of the following lineage represent the pattern of speciation by cladogenesis?

QUESTION ID:39

Red hair is a recessive trait in human. In a randomly mating population in Hardy-Weinberg equilibrium approximately 9% of individuals are red- haired. What is the frequency of the heterozygotes?

QUESTION ID:40

Interrupted mating experiments were performed using three different Hfr strains (1-3). The three strains have different combinations of selectable markers. The time of entry for markers for each strain is shown is shown in the table given.Using the above data, predict the correct sequence of markers on the E. coli chromosome.

QUESTION ID:41

Paripatus is an interesting living animal having unjointed legs, nephridia, haemocoel, trachea, dorsal tubular heart, claws, jaws, continuous muscle layers in body wall. This is considered as a connecting link between

QUESTION ID:42

The following schematic diagram represents secondary growth in angiospermsBased on above scheme which of the following option represents correct identity of the cambia labelled as A, B, C and D

QUESTION ID:43

The table below list the major fungal groups and their characteristics:Fungal Groups                          CharacteristicsWhich of the following represents the appropriate match between the fungal group and their characteristics?

QUESTION ID:44

As a biologist you want to classify three taxa, A, B and C. You have the information of the three traits, p, q and r. The trait that is ancestral is counted “0” and the trait that is derived is counted as “1”. The distribution of the trait found in the three taxa given belowBased on the above table the following cladograms were drawn:Based on the trait distribution and the principle of parsimony select the correct option:

QUESTION ID:45

Given below are some pathogens and diseases of humans, animals and plants.Pathogen                                                         DiseaseWhich of the following is the match between the pathogen and the disease caused?

QUESTION ID:46

Given below are statements pertaining to organisms belonging to three domains of life. Identify INCORRECT statement.

QUESTION ID:47

You observed the two species of barnacles, species 1 and species 2, occupy upper and lower strata of intertidal rocks, respectively. Only when species 2 was removed by you from the lowers strata, species 1 could occupy both the upper and lower strata. From the choice given below what would be your inference from these observations.

QUESTION ID:48

In natural system, a species producing large number of offsprings with little or no parental care generally exhibits which one of the following kind of survivorship curve (2)

QUESTION ID:49

Match the correct local names of temperate grasslands with their geographical range

QUESTION ID:50

Following is the hypothetical life table for speciesWhich one of the following is the correct net reproductive rate (R0)

QUESTION ID:51

Which one of the following statements is true for trends of the dissolved oxygen (DO) and biological oxygen demand in water stream receivingpollutants from point source

QUESTION ID:52

Following are the graphical representation of various hypothesis proposed for explaining the possible relationship between the species richnesson (X) axis and community services on (Y) axis.Which of the following is the correct match between the graphical representation and the hypothesis

QUESTION ID:53

Agobacterium Ti plasmid vectors are used to generate transgenic plants. The following are examples of vir gene encoded proteins that are important for transfer of T-DNA in to plants.

A- vir E, single stranded DNA binding protein

B- virD2 that generates T-strands

C- vir A that sense plant phenolic compounds

D- vir F which directs T complex proteins for destruction in proteasome

Which one of the following combination of the proteins functions inside the plant cell?

QUESTION ID:54

Researcher is investigating structural changes in protein by following tryptophan fluorescence and by Circular dichorism. Fluorescence and CD spectraof pure protein were obtaining the absence of any treatment (a), in the presence of 0.5 molar urea (b), upon adding acrylamide, a quencher of tryptophan(c) and upon heating (d) the data are shown below.Which one of the following statements is correct?

QUESTION ID:55

Polynucleotide kinase (PNK) is frequently used for radio labeling DNA or RNA by phosphorylating 5’ end of non-phosphorylated polynucleotide gene.Which of the following statements about PNK is NOT true?

QUESTION ID:56

A gene encoding for protein X was cloned in an expression vector under the T7 RNA polymerase promoter and lac operator. Cells were incubated bythe addition of 1 mM IPTG at 370 c for 6 h. Cells were lysed and fractionised into insoluble bodies. Which one of the following strategies would you use to express protein X in the soluble fraction (cell free supernatant)?

QUESTION ID:57

Engineering of metabolic pathways in plants can be achieved by introduction and overexpression of appropriate candidate gene(s) using transgenictechnology. The figure given below represents a biochemical pathway in plants where a precursor molecule ‘A’ is converted in to products ‘T’ and ‘X’through a series of enzymatic reactions. Enzymes 1- 5 are involved in this pathway. Scientists attempted to increase the levels of ‘X’ by introducing additional copy of the gene for enzyme ‘5’ under transcriptional control of a strong constitutive promoter. However, the developed transgenic plants did not display a proportionate increase in the level of ‘X’.The following statements were proposed for explaining the above results: A- Enzyme ‘4’ has greater affinity for D than enzyme ‘3’B- Feedback inhibition of enzyme ‘5’ by compound X C- Substrate limitation for enzyme ‘5’Which of the above statement could represent probable reasons for NOT obtaining proportionate increase in the amount of ‘X’ in the transgenic plants?

QUESTION ID:58

A single copy homozygous transgenic plant containing the transgene 'A ' for fungal resistance was subsequently re-transformed with another gene' B' for conforming resistance to salt stress. The selection marker genes used for both the transformation experiment were different.Transgenic plant obtained following the retransformation experiment were screened for salt stress resistance and single copy event were identified by southern hybridization. These single copy event were self - pollinated. In the event of the two T-DNA (containing the A and B transgenes) getting integrated in unlinked location in all transgenic plants, the phenotypic ratios among the T1 progeny would be:

QUESTION ID:59

You are inserting a gene of 2 kb length in to a vector of 3kb to make a GST fusion protein the gene is being inserted at the E. coli site and the insert hasa Hind III site 500bp downstream of the first codon. You are screening for the clone with the correct orientation by a restriction digestion of the plasmidusing Hind III plus Bam HI (H+P) and Hind iii plus PSTI (H+P) the map of the relevant region of the vector is shown belowWhich of the plasmid shown above represents the clone in the correct orientation?

QUESTION ID:60

The frequency of M-N blood types in a population of 6129 individuals is as follows:The frequency of LN allele in this population is

QUESTION ID:61

Mayfair genes (HYPOTHETICAL) consist of a superfamily of transcription factors. They are found in 4 clusters in mammals; in 2 clusters in insects; andin a single cluster in an ancestor to insects. These data consistent with all of the following explanations EXCEPT:

QUESTION ID:62

Fluorescence recovery after photo bleaching (FRAP) is a method to estimate the diffusion of molecules in a membrane. Fluorescently labelled in a membrane such asi) a receptor tagged with green fluorescent protein (GFP)ii) a receptor labelled with GFP which interacts with cytoskeletoniii) a labelled lipidiv) a labelled protein that binds to the membrane surfaceare photo bleached and the recovery profiles ( a-d) were obtained to estimate their diffusion coefficientsThe following data were obtained.Which one of the combination is correct?