Previous Year Questions

QUESTION ID:2

Following statements have been made about removal of supercoiling produced by DNA unwinding at the replication fork:

A. Accumulation of supercoils is the result of DNA helicase activity during unwinding of DNA

B. Problem of DNA supercoiling is valid only for circular chromosomes of bacteriaand not for the linear chromosomes

C. Supercoiling of DNA is removed by topoisomerases by breaking either one or both strands of DNA on the unreplicated DNA in front of replication fork.

D. Both topoisomerase I and topoisomerase can remove positive super-coiling during replication

Which one of the following options has all correct statements?

QUESTION ID:3

Phosphorylation of the α-subunit of elF2 at Ser 51position in Saccharomyces cerevisiae leads to sequestration of eIF2B, guanosine exchange factor. This phenomenon is

QUESTION ID:4

E. coli mutants isolated from a genetic screen showed following classes of mutations

A. Point mutations in lacI

B. Deletions immediately downstream of the transcription

start site of the lacZYA mRNA

C. Duplications of part or whole of lacY

D. Duplications of part or whole of Lac A

Choose the option which is likely to result in constitutive expression of the lac operon?

QUESTION ID:5

For Escherichia coli chromosomal DNA replication, which one of the following statements is true?

QUESTION ID:6

Following observations were made about variations among genomes of eukaryotic organisms:

 A. Single nucleotide polymorphisms are the numerically most abundant type of genetic variants

 B. Both. interspersed and tandem repeated sequences can show polymorphic variation

 C. Mitotic recombination between mispaired repeats causes change in copy number and generates minisatellite diversity in population

 D. Smaller variable segments in the genome can be identified by paired end mapping technique

Select the option with all correct statements

QUESTION ID:7

There are number of specific T cell surface molecules involved in various functions ofadaptive immune response. Column X represents a list of T cell surface molecules and Column Y with the possible functional characteristics:

Which of the following option has all correct matches?

QUESTION ID:8

In an experiment it was observed that a protein was upregulated in cancer tissues (compared to control tissues) that showed correlation with disease progression. Following are a few possibilities, which can explain the above observation.

A. A mutation could be located in the 3'UTR of the corresponding mRNA at a miRNA binding site.

B. A mutation changes the conformation of the protein, resulting in its better stability.

C. A mutation in the corresponding mRNA promotes ribosome read-through of the termination codon resulting in increased synthesis of the protein.

D. A mutation in the corresponding mRNA increased the stability of the RNA due to change in secondary structure.

Which one of the following combinations represents the most likely explanations?

QUESTION ID:9

The extracellular matrix contains a number of non-collagen proteins that typically have multiple domains, each with specific binding sites for other matrix molecules and cell surface receptors. These proteins therefore contribute to both organizing the matrix and helping cells attach to it. The most well characterized matrix protein of this kind is fibronectin. Which one of the following characteristics is NOT TRUE for fibronectin?

QUESTION ID:10

Following are the list of some cellular receptors (Column X) and with possible functional characteristics (Column Y):

Which one of the following is the correct match?

QUESTION ID:11

In a laboratory experiment it was observed that both 'Virus A' and 'Virus B' could infect a mammalian host cell, when infected individually. Interestingly, if the cell were first infected with Virus A (with large MOI), Virus B failed to infect the same cell. If the Virus B (with large MOI) is added first followed by Virus A, both the virus can infect the cells. However, infection with 'Virus A' was found to be in lesser extent. Considering X and Y are the receptors/co-receptors. Which may be involved for the virus entry, following are few possibilities that can explain the observation.

A. 'Virus A' uses 'X' as receptor and Y as coreceptor.

B. 'Virus B' uses exclusively 'Y' as receptor for entry:

C. Both 'Virus A' and 'Virus B' need X as receptor.

Choose the option with all correct statements.

QUESTION ID:12

While testing the effect of several potent anti-cancer compounds on cycling human oral cancer cells, a student observed that a major percentage of cells showed dose-deep cell death after 12 hours of drug treatment. However the remaining cells repopulated the culture dish once the compounds were removed and the cells were cultured in complete medium. The student made the following assumptions:

A. Not all cells were equally affected by the compounds as they were not synchronized before treatment.

B. The compound selectively killed cells which were in Go phase.

C. The cancer stem cells were impervious to the effects of the compounds and therefore repopulated the culture.

D. The cancer cells differentiated into a mesenchymal phenotype and grew in fresh culture medium containing inhibitors of epithelial-to-mesenchymal transition (EMT).

Which one of the following combination of assumptions would best justify the results?

QUESTION ID:13

When 8-cell embryo of tunicates is separated into 4 blastomere pairs and allowed to grow independently in culture medium, then each blastomere pair can form most the cell types; however, cells for nervous system are not developed. The following statements are formed from the above observations:

A. Nervous system development demonstrated autonomous specification.

B. The other tissue types are formed due to conditional specification.

C. All the tissue types, except nervous tissues that developed demonstrated autonomous specification.

D. Nervous system development demon strated conditional specification.

The correct combination of statements that explains the above result is:

QUESTION ID:14

During wing development in chick, if Apical Ectodermal Ridge (AER) is removed, the limb development ceases, on the other hand placing leg mesenchyme directly beneath the wing AER, distal hindlimb structures develop at the end of the wing, and if replaced by non-limb mesnchyme sheath AER, the AER regresses. This may demonstrate that:

A. the limb mesenchyme cells induce and sustain AER.

B. the mesenchyme cells specify the type: wing or limb.

C. the AER is responsible for specifying the type: wing or limb.

D. the AER is responsible for sustained outgrowth and development of the limb

E. the AER does not specify the type: wing or limb.

Which combination of above statements is demonstrated by the experiment?

QUESTION ID:15

The following statements regarding the generation of dorsal/ventral axis in Drosophila was made:

A. Gurken protein moves along with the oocyte nucleus and signals follicle cells to adopt the ventral fate.

B. Maternal deficiencies of either the gurken or torpedo gene cause ventralization of the embryo.

C. Gurken is active only in the oocytes, Torpedo is active only in the somatic follicle cells.

D. The Pipe protein is made in the dorsal follicle cells.

E. The highest concentration of Dorsal is in the dorsal cell nuclei, which becomes the mesoderm.

Which one of the following combination of the above statements is true?

QUESTION ID:16

A specialized area of teratogenesis involves the misregulation of the endocrine system. Which one of the following statements regarding endocrine disruptors is true?

QUESTION ID:17

Given below are statements related to different aspects of plant growth and development.

A. Leaf longevity is increased in ethylene insensitive mutants eir1-1 and ein2 of Arabidopsis.

B. Programmed cell death (PCD) is responsible for the formation of prickles, thorns and spines in plants.

C. Senescence and PCD occur only in the development of vegetative tissues and does not occur in reproductive tissues

D. Redifferentiation of organelles is an integral component during initial stages of senescence in plants.

Which one of the following represents the combination of all correct statements?

QUESTION ID:18

The following demonstrates proposed functions of different genes which determine the decision to become either trophoblast or inner cell mass (ICM) blastomere during early mammalian development:

Based on the above figure, which one of the following assumptions is correct?

QUESTION ID:19

Jasmonate is known to inhibit root growth while auxin facilitates root growth. Upon infection with pathogenic bacteria that produce coronatine, we may expect the following in plants:

A. Upregulation of COI-1 gene and inhibition of root growth.

B. Upregulation of Auxl-1 gene and inhibition of root growth.

C. Inhibition of AuxI-1 gene and promotion of root growth.

D. Inhibition of COI-1 gene and promotion of root growth.

Which one of the following is correct?

QUESTION ID:20

Following are certain statements with regard to plant respiration:

A. Metabolism of glucose into pyruvate through glycolysis generates NADH and not NADPH.

B. Metabolism of glucose through oxidative pentose phosphate cycle does not produce NADPH.

C. Cyanide forms a complex with haem iron of cytochrome oxidase leading to prevention of change in valency, which in turn stops electron transport in therespiratory chain.

D. Alternative oxidase is insensitive to cyanide and has higher Km than that of cytochrome oxidase.

Which one of the following combinations is correct?

QUESTION ID:21

Blue light receptor cry1 binds to COP1 and SPA1 complex by interacting with C-terminal region of cry1 (CCT) in a light dependent manner and regulates photomorphogenesis via transcription factor HY5. Read the following statements:

A. cry 1 binds to COP 1 and SPA1 complex leading to degradation of HY5.

B. cry1 binds to CON and SPA1 complex and prevents degradation of HY5.

C. CCT is overexpressed and the plant are kept in dark.

D. CCT is overexpressed and the plants are kept in light.

Which of the following combination of above statements will result in photo-morphogenesis?

QUESTION ID:22

After absorbing light, chlorophyll molecules in green plants exist in singlet and triplet states.

Following are certain statement on singlet and triplet states of chlorophyll molecules:

A. Singlet state is short lived compared to triplet state.

B: Singlet state is long lived compared to triplet state.

C. Singlet state contains electrons with anti parallel. spins while triplet state has electrons with parallel spins.

D. Singlet state contains electrons with parallel spins while triplet state has electrons with anti-parallel spins.

Which one of the following combinations is correct

QUESTION ID:23

Only members of the plant kingdom and many bacteria have capability of biological nitrogen reduction. In this regard following statements are given:

A. Nitrogen is normally taken by the plant in their fully

oxidized form but needs to be reduced before incorporation in organic molecules.

B. Conversion of oxidized nitrogen into reduced nitrogen

needs energy in the form of NAD(P).

C. The metal associated with the enzyme nitrate reductase is Magnesium.

D. Nitrate reduction takes place in the cytoplasm,whereas

nitrite reduction takes place in chloroplast.

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

QUESTION ID:24

During interaction with host, phytopathogens are known to deliver effector is directly into the host cells. The following statements were made regarding the role of these effector proteins.

 A. May promote pathogen virulence.

 B. May elicit avirulence response.

 C. May suppress defense response.

 D. May promote plant growth.

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

QUESTION ID:25

The CO2 dissociation curves of oxygenated and deoxygenated blood are given along with dissolved CO2: below

Following are the statements deduced from the curves above and or based on the knowledge about CO2 transport, which may or may not be correct:

A. The deoxygenated haemoglobin has greater affinity for CO, than oxygenated haemoglobin.

B. The deoxygenated haemoglobin does not bind with free H+ ions released during theformation of HCO3- from CO2.

C. The haemoglobin saturation with O2 has no effect on CO2, dissociation curve.

D. O2 and CO2 bind to haemoglobin at different sites.

Which one of the following options represents a combination of all correct statements?

QUESTION ID:26

Given below are the different intervals/ durations of electrocardiogram of a humansubject (column A) and the events in heart during the process (column B).

Which one of the following options is a correct match of entries in columns A and B?

QUESTION ID:27

The pathway of synthesis of aldosterone in zona glomerulosa along with the intracellular locations is shown below:

Which one of due following options represents correct matches for A, B and C?

QUESTION ID:28

Given below is a figure of pro-opio melanocortin (POMC) polypeptide and its cleavage products (marked as A, B, C, D) which have different hormonal activities. The names of the cleaved products obtained from POMC are shown in the table below the diagram.

Which one of due following options represents A. B, C and D correctly?

QUESTION ID:29

During prolonged illumination,rhodopsin is desentitized which leads to the termination of visual response.The associated proteins (Colum A) and their effects (Column B) are given below:

Which one of the matched combinations is correct.

QUESTION ID:30

Estrus cycle in rats is controlled by pituitary and gonadal harmones.While treating a set of rat with vitamin D, a student accidentally injected the rat with an inhibitor of 17 α- hydroxypregnenolone and checked vaginal smear for 10 consecutive days.

Which one of the following observation is correct?

QUESTION ID:31

Centromere postions can be mapped in linear tetrads in some fungi. A cross was made between two strains a b and a+b+ and 100 linear tetrads were analysed. The genes a and b are located on two arms of the chromosome. The tetrad were divided into 5 classes as shown below.

Based on the above observation the following conclusion were drawn:

(A) Class 1 is a result of a cross over between ‘a’ and the centromere.

(B) Class 2 is result of double crossover involving 3 strands between ‘a’ and the centromere.

(C) Class 5 is a result of a double crossover between ‘a’ centromere and ‘b’ centromere.

(D) Class 4 is a result of a double cross over involving all the 4 strands.

Which one of the following options represents all correct statements?

QUESTION ID:32

Two Yellow mice with straight hair were crossed and the following progeny was obtained:

1/2 Yellow, straight hair

1/6 Yellow, fuzzy hair

1/4 gray, straight hair

1/12 gray, fuzzy hair

In order to provide genetic explanation for the results and assign genotypes to the parents and progeny of this cross the following statements were given:

(A) The 6:2:3:1 ratio obtained here indicates recessive epistasis.

(B) This cross concerns two independent characteristics –body colour and type of hair.

(C) The deviation of dihybrid ratio from 9:3:3:1 to 6:2:3:1 may be due to one of the genes being a recessive lethal

(D) The lethal allele is associated with straight hair

The most appropriate combination of statements to provide genetic explanation for the result is:

QUESTION ID:33

A Family was examined for a given trait which is represented in the pedigree shown below. Further, the degree of expression of the trait is highly variable among members of the family; some are only slightly affected while others developed severe symptoms at an early stage

The following statements are made to explain the pattern of inheritance shown in the pedigree.

(A)X-linked dominant mutation

(B) X-linked recessive mutation

(C) Mitochondrial inheritance

(D) Vairiable expression can be due to heteroplasty

The best possible explanation for this inheritance is

QUESTION ID:34

The location of six deletion (Shows as solid line underneath the chromosomes) has been mapped to the Drosophila chromosome as shown in the diagram given below:

The recessive mutations a, b, c, d, e f and g are known to be located in the region of deletions, but order of mutations on the chromosome is not known. When flies homozygous for the recessive mutations are crossed with flies homozygous for the deletion, the following result were obtained where the letter ‘m’ represents a mutant phenotype and ‘+’ represents the wild type.

The relative order of the seven mutant genes on chromosome is :

QUESTION ID:35

In the following pedigree , individuals with shaded circle or shaded square show presence of a recessive autosomal trait.

The calculated risk of occurance of this trait for III-I is

QUESTION ID:36

During the course of vertebrate evolution , the jaw bones got modified into three ear ossicles in mammals. Which one of the following is a correct match of ear ossicle and its ancestral jaw bone ?

QUESTION ID:37

Given below are names of the animals in column X and the accessory respiratory organs teleost fishes (Column Y).

The correct match of the animals with the accessory respiratory organs they have are:

QUESTION ID:38

The terms expressing some of the developmental events or specific body structures are given in column X and the names of animals that are associated with them in column Y:

The correct match of the terms in column X with the name of animals in column Y is:

QUESTION ID:39

The table lists characteristic anatomical features and names of plants.

Choose the option that correctly matches plant with their characteristic features.

QUESTION ID:40

The table given below provides a list of female gametophyte features and plant genera

Which one of the following options correctly matches the plant genera to female gametophyte features:

QUESTION ID:41

Following are some generalizations related to wood anatomy of higher plants:

A. The axial system of conifer woods consist mainly or entirely of tracheids.

B. The rays of conifers typically contain only parenchyma cells.

C. The rays of angiosperms typically contain both sclerenchyma cells and tracheids.

D. Angiosperm wood may be either diffuse porous or ring-porous.

Which one of the following options represents all correct statements?

QUESTION ID:42

A field ecologist gathers following data (abundance values) in order to study diversity of species in four plant communities.

Based on the above observations, the ecologist draws following conclusions:

A. Plant communities C1 and C4 show strong similarity with each other

B. Plant communities C1 and C4 as well as communities C2 and C3 show strong similarity with each other

C. Plant community C1 is most diverse

D. Plant community C4 is most diverse

Which of the following statements is correct regarding above conclusions?

QUESTION ID:43

The table given below lists types of plant communities and types of growth forms.

Which of the following is the best match for the plant communities with most dominant growth form generally present in that community?

QUESTION ID:44

Following are some of the generalizations regarding energy flow in an ecosystem:

A. Assimilation efficiency of carnivores is higher than herbivores.

B. Consumption efficiency of aquatic herbivores is higher than terrestrial herbivores.

C. Vertebrates have higher production efficiencies than invertebrates.

D. Trophic level transfer efficiency is higher in terrestrial food chains than in marine.

Based on the above, select the correct option.

QUESTION ID:45

In an experiment to show that biogeochemical cycles interact, nitrogen fixing vines (Galactia sp.) were grown in plots under normal levels of CO2 (Control) and under artificially elevated atmospheric CO2 (Experimental). Effect of elevated CO2 levels on nitrogen fixation was measured over a period of 7 years (Plot A) and the concentrations of iron and molybdenum in the leaves of these plants were quantified at the end of the study (Plot B). Which one of the following inferences CANNOT be made from the above experiment?

QUESTION ID:46

Match the following invasive plants to the likely habitats in which they are expected to occur:

QUESTION ID:47

Incorporating additional ecological factors into the Lotka-Voltera predator-prey model can change the predator isocline. Given below are three state-space graphs (A-C) representing modification of predator isocline due to the ecological factors listed below (i-iii).

(i) Victim abundance acting as predator carrying capacity

(ii) Availability of alternate prey (victim) population

(iii) Predator carrying capacity determined

Which one of the following options represents all correct matches of the state space graphs with their ecological factor?

QUESTION ID:48

Birds in a population show two foraging phenotypes: A and B. Birds of phenotype A search, attack and capture prey while birds of phenotype B steal prey from birds of phenotype A. A and B are maintained in the population through negative frequency-dependent selection. The graph below shows the fitness of A (broken line) and B (solid line) at different relative frequencies of A (frequency of B = 1-frequency of A).

Which of the following statements does the grap support?

QUESTION ID:49

Antelopes are proposed to form groups to reduce the risk of predation. A researcher measured the predation of individuals in groups of different sizes. She found that per capita mortality risk decreased with increasing group size for males (solid line) but remained unchanged for female (dashed line). Furthermore, males in all groups experienced greater per capita mortality risk than females.

Identify the graph below that best depicts the above findings:

QUESTION ID:50

The prominent mammal species found in four different protected areas are listed below:

Area A: Tiger, Wild dog, Leopard, Elephant

Area B: Common langur. Barking deer, Wild dog, Elephant

Area C: Tiger, Indian rhinoceros, Pygmy hog, Wild pig

The area with the greatest phylogenetic diversity is

QUESTION ID:51

The Hardy-Weinberg principle states that allele frequencies in a population will remain constant over generations if certain assumptions are met.

A. Random mating

B. Mate choice

C. Small population size

D. Large population size

E. Lack of mutations

F. Directional selection

Which of the above factors will cause changes in allele frequencies overgenerations?

QUESTION ID:52

Given below are few traits and related functions:

Match the above given traits to their most likely functions.

QUESTION ID:53

Following is a diagrammatic representation of human evolutionary tree.

In the above diagram A, B, C and D respectively represent:

QUESTION ID:54

Based upon phenotypic observation, it was concluded that an unknown gene responsible for an agronomically important trait is present in a particular plant. In order to identify the gene, a researcher proposes to use the following strategies:

A. PCR amplification of the gene.

B. Map based cloning of the gene.

C. Subtractive DNA hybridization

D. Genome sequencing

E. Develop molecular markers linked to the trait

Which one of the following options is most suitable for identifying unknown gene?

QUESTION ID:55

A To transgenic plant contains two unlinked copies of the T- DNA of which one is functional and the other is silenced. Segregation of the transgenic to non transgenic phenotype would occur in a

(i) Ratio in progeny obtained by backcrossing and in a

(ii) ration in F1 progeny obtained by self pollination.

Fill in the blanks with the correct combination of (i) and

(ii) from the options given below:

QUESTION ID:56

Column X lists two diseases and column Y lists name of proteins which are commonly used for routine clinical diagnosis of these diseases

Find out correct combination.

QUESTION ID:57

Given below are the steps to assess the population size of grasshoppers in a given area:

A. 'n' individuals are collected randomly from the study area in a defined period of time.

B. The captured individuals are counted, marked and released at the site of collection.

Next day, individuals are captured from the same site for same length of time. Number of marked (nM) and unmarked (nU)

C. This capture-release and recapture is continued till one gets 100% marked individuals

D. The size of the population (N) is estimated as follows:

E. The size of population (N) is estimated as follows:

The most appropriate combination of steps for estimating population size using mark-recapture method is:

QUESTION ID:58

A neurophysiolgist was interested in using the patch-clamp technique. Following statements are related to this technique:

A. Intracellular movement of ion channels.

B. Post–translational modification of the ion channel protein

C. Ligand that controls the opening or closing of ion channels.

D. Change in current flow in a single ion channel.

Which one of the following combinations will be achievable using the patch-clamp technique?

QUESTION ID:59

The blood plasma proteins(albumin and globulins) from a healthy person were separated by electrophoresis as shown above. The diagnosis of acute inflammation can be done based on one of the following observations.

QUESTION ID:60

Following statements were given regarding factors influencing variation in expression levels of transgene in transgenic plants:

A. Difference in restriction enzyme sites within the T- DNA.

B. Difference in copy number of the transgene.

C. Variations in site of integration of the T- DNA within the plant genome.

D. Presence of multiple promoters within the T-DNA region.

Which one of the following options represents a combinations of statements that would NOT lead to variations in transgene expression levels in transgenic

plants generated using the same T-DNA/ binary vector?

QUESTION ID:61

The above figure shows the fluorescence emission spectra of three different proteins; Protein (X), Protein (Y), and Protein (Z) excited at 280 nm. Which one of the following statements gives the correct interpretation?

QUESTION ID:62

Specimens for light microscopy are commonly fixed with a solution containing chemicals that crosslink/denature cellular constituents. Commonly used fixatives such as formaldehyde and methanol could act in various ways as described below:

A. Formaldehyde crosslinks amino groups on adjacent molecules and stabilizes protein-protein and protein-nucleic acid interactions.

B. Methanol acts as a denaturing fixative and acts by reducing the solubility of protein molecules by disrupting hydrophobic interactions.

C. Formaldehyde crosslinks lipid tails in biological membranes.

D. Methanol acts on nucleic acids. crosslinks nucleic acids with proteins and thus stabilizes protein-nucleic acid interactions.

Which one of the following combinations represents all correct statements?

QUESTION ID:63

Run off transcription assays were performed to establish the specificity of three novel sigma factors for their promoters. Result of the experiments are shown below:

Following inferences were made from these results:

A. σA intiates transcription from P2 and σB from P1

B. σC can intiates transcription from both promoters.

C. σB Prevents intiation of transcription from P2

D. σA Intiates transcription from P1

Choose the option that correctly interprets that results?