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QUESTION ID:1

The plaque morphology of wild type and r/1 mutants of T 4 bacteriophage following infection of different E. coli strains is summarized below.

  The following two experiments were carried out:

Experiment I: Co-infection of two independent r/1 mutants on E. coli K strain resulted in several plaques, all being small and ragged.

Experiment II: E. coli B strain was co-infected with the above r/1 mutants. T4 phages from the resulting plaques were used to infect E. coli K strain. Few plaques were obtained, which were all small and ragged.

Based on the observations, the following statements were made:

A. Experiment I indicates that the two mutants are allelic.

B. Experiment II indicates that the wild type T4 phages that infected E. coli K strain resulted from a recombination event.

C. In experiment II, if the T4 phage isolated from the E. coli B strain was used to infect E. coli B strain, all plaques would be large and round.


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

QUESTION ID:2

The following statements describe different patterns of sequence evolution.
A. Most non-synonymous mutations are selected against.
B. Synonymous mutations can accumulate.
C. The ratio of non-synonymous to synonymous substitutions is high.
D. Non-synonymous sites accumulate mutations at higher rates.

Which one of the options is NOT true about sequence evolution under purifying selection?

QUESTION ID:3

Phylogenetic trees are used to examine
A. relatedness among different populations, species or genera.
B. similarity in characters among different populations, species or genera.
C. common ancestry among different populations, species or genera.
D. functional significance of traits in populations, species or genera.

From the above statements, select the correct combination of statements that best represent the utility of phylogenetic trees.

QUESTION ID:4

Which one of the options below includes habitats that are ALL found in the Indian subcontinent?

QUESTION ID:5

Which of the following options represents the correct order of increasing biological organisation?

QUESTION ID:6

Given below are a few statements on transgenic plants.
A. Transgenic plants generated using a transformation vector with the CaMV35S promoter-GUS-35SpA cassette can show variations in expression levels of GUS protein in independent transgenic events due to differences in strength of promoter used to express the GUS gene.
B. A transgenic plant containing two insertions of the transgene cassette as inverted repeats in tandem would segregate in a 3: 1 ratio for the transgenic phenotype on backcrossing the transgenic plant with the untransformed parent.
C. A transgene containing a potential polyadenylation signal in its coding sequence would generate full-length transgene mRNA but a truncated transgenic protein.
D. A gene-pyramiding experiment to bring together two transgenic traits by crossing independent homozygous single-copy transgenic lines for each trait would produce a plant homozygous for both the transgenes in the F2 generation.

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

QUESTION ID:7

A researcher used CRISPR-Cas9 system and observed a different type of mutation in two alleles of a target gene in a To transgenic plant. These mutations are designated as follows:
Allele 1: addition of a nucleotide
Allele 2: deletion of a nucleotide

The observed mutations can be classified as

QUESTION ID:8

In a line transect of length Land half-width w, designed for estimating the density of gaur (~ D=N/2Lw), N animals were counted .

The following statements represent possible assumptions about population sampling.
A. The probability of detection is independent of distance from the transect line.
B. The animals in question are uniformly distributed through the study area.
C. The animals are deemed to be stationary and thus detected only once during the sampling.
D. Animals on the line will be detected with a probability equal to 1.

Select the options that are considered as assumptions in line transect sampling.

QUESTION ID:9

Recessive mutations in the human dysferlin gene lead to Limb Girdle type II muscular dystrophy. The gene is located on the second chromosome. The patient's parents do not have Limb Girdle type II dystrophy B. What is the probability that at least one of the four grandparents of this patient suffered from this disease?

QUESTION ID:10

In the classic ABCDE model of flower development, different combinations of ABCDE class genes result in different whorls of organs. Which one of the following models would likely give rise to unisexual flower structures? 

QUESTION ID:11

Following statements were made with respect to plant steroid hormones.
A. The receptors for plant steroid hormones are found in the nucleus, similar to animal steroid hormones.
B. There are multiple pathways for the plant steroid hormone biosynthesis involving cytochrome P450 class of enzymes.
C. The first plant steroid hormone was isolated from male gametophytes.
D. Plants deficient for the steroid hormone brassinosteroid show underproliferation of phloem and over proliferation of xylem cells.
E. Castasterone is a plant steroid hormone abundant in the vegetative tissues of the plant.

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

QUESTION ID:12

Which one of the following options represents all correct matches between Column X and Column Y?

Column X: Microorganism

Column Y: Host receptor

A. Influenza virus

i.

N-acetylglucosamine

B. Entamoeba histolytica

ii.

CD44

C. Streptococcus pyogenes

iii.

Sialic acid residues of glycoproteins and glycolipids

D. Human immunodeficiency virus

iv.

CD4

QUESTION ID:13

The table below represents a list of animals and larval stages.

Animal

Larval stage

a. sponges

i.

cercariae

b. cnidarian

ii.

amphiblastula

c. flatworms

iii.

planula

Which one of the following options represents the combination of all correct matches:

QUESTION ID:14

Given below are the blood clotting factors in column X and their names in column Y.

Column X

Column Y

a. XII

i.

Fitzgerald factor

b. HMWK

ii.

Laki-Lorand factor

c. Pre-Ka

iii.

Stuart-Prower factor

d. X

iv.

Fletcher factor

Which of the following combination is a correct match of the factor with its name.

QUESTION ID:15

The theoretical resolution limit of the fluorescence microscope is about 200 nm. Super-resolution microscopy has been developed to address this limitation. Given below are super-resolution microscopy methods in column X and their principle in column Y. 

Super-resolution microscopy (Column X)

Principle (Column Y)

A. Structured illumination microscopy (SIM)

(i)

focused excitation laser point is surrounded by donut-shaped depletion beam

B. Stimulated emission depletion (STED) microscopy

(ii)

the specimen is illuminated with a pattern of light and dark stripes to generate Moire fringes

C. Photoactivated localization microscopy (PALM)

(iii)

utilizes variant of GFP that is activated by a wavelength different from its excitation wavelength

Which one of the following options represents the correct match between column X and column Y?

QUESTION ID:16

URA3 gene expression allows yeast cells to grow on synthetic media lacking Uracil (SC-URA). Shown below are cell types having URA3 gene inserted at distinct positions of the chromosome. The ability of each cell type to grow on SC-URA in either log or stationary phase is listed on the right.

The following interpretations were made:

A. URA3 gene in cell type 1 is probably located in a heterochromatic region.

B. URA3 gene in cell type 2 is located in facultative heterochromatin.

C. URA3 gene in cell type 2 is probably located in a chromosome region silenced in log phase.

D. URA3 gene in cell type 3 is heterochromatinized in log phase.


Which one of the following options are correct interpretations?

QUESTION ID:17

The following statements have been made regarding cell specification in an early embryo:
A. The entire embryo rarely interacts with its environment, and its developmental trajectory cannot be guided by its immediate "ecosystem".
B. When cells are removed, changes in cellular biochemistry and function are never preceded by a process involving the commitment of the cell to a certain fate.
C. The fate of a cell or a tissue in the intact embryo is said to be specified when it is not capable of differentiating autonomously on being placed in a neutral environment, such as a petri dish or test tube.
D. If cells are removed, the interactions of the remaining cells compensate the fate of the removed cells, because the fate of a cell depends upon the conditions in which the cell finds itself.

With regard to the experiment shown below, where removal of cells from an early blastula leads to normal development of the larval form, which one of the above combination of statements apply to the development of the organism? 

QUESTION ID:18

In a protein stability study, three solutions, MolA (10 kDa) at 0.5 mM, MolB (20 kDa) at 0.5 mM, and MolC (20 kDa) at 1 mM, were subjected to denaturation by urea, SOS and guanidium hydrochloride (GnHCI), respectively. The profiles of the fraction of unfolded protein with increasing concentration of the denaturants is given below. 

Which one of the following corresponds to reaction conditions at which the number of molecules of folded protein are equal, assuming the reaction volumes to be the same for all experiments?

QUESTION ID:19

SLN1 receptor, a part of a two-component system, is required for osmoregulation in yeast. The yeast mutant (sln1) lacking the SLN1 receptor protein dies. A researcher tries to rescue the mutant by expressing an Arabidopsis gene for the cytokinin receptor, CRE1 , which like SLN1 is also a histidine kinase that acts through a two-component system.

The following statements are made regarding the outcome of the experiment.
A. SLN1 and CRE1 proteins respond to the same external signals and therefore, CRE1 rescues the yeast mutant.
B. As CRE1 cannot interact with the downstream signaling pathway in the yeast, it will not rescue the yeast mutant.
C. CRE1 will rescue the yeast mutant, only if cytokinin is present.
D. The effector domains of CRE1 and SLN1 proteins are sufficiently similar and therefore, CRE1 can induce the downstream signaling pathway and rescue the yeast mutant.

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

QUESTION ID:20

The interpretation of any clinical laboratory test is done by comparing the patient's results to the test's reference intervals. For example, the reference interval for white blood cells (WBC) in human adults is 4,500 - 11,000 cells/ microliter. Estimation of this reference interval is done by testing

QUESTION ID:21

For a population that grows exponentially in the time interval (t, t+1 ), we have Nt+1 = R Nt, where N denotes population size and R denotes the growth rate. Under intraspecific competition where births and deaths are density dependent, we expect the population to stabilize at carrying capacity, K. In the figure below, Nt/Nt+1 is plotted as a linear function of Nt. 

We may write down the linear equation for the line joining A with B and derive a model for density-dependent population growth under intraspecific competition . Denoting (R-1 )/K as a, which of the following is the correct relationship that describes population growth? 

QUESTION ID:22

Given below are statements on concepts of genetics.
A. The degree to which a particular gene is expressed in a phenotype is called__________
B. A heritable change in gene expression that does not result from a change in the nucleotide sequence of the genome is called ________ change.
C. The frequency with which a dominant or homozygous recessive gene is phenotypically expressed within a population is called ________
D. An allele that results in the death of organisms that is homozygous for the allele is ________

Which one of the following options represents the most appropriate sequence of terms to fill all the blank spaces in the above statements?

QUESTION ID:23

The stimulation of sympathetic cardiac nerves increases the rate of action potential generation from the sinoatrial (SA) node of heart. The following statements suggest the mechanism of this action:
A. The depolarizing effect of 'h' current (Ih) is decreased by sympathetic stimulation.
B. Norepinephrine secreted by the sympathetic endings binds to !β1 adrenoceptors resulting in the increase of intracellular cAMP.
C. The increased intracellular cAMP facilitates the opening of long-lasting (L) Ca++ channels.
D. The ca++ current (Ica) due to the opening of voltage-gated L Ca++ channels is decreased.

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

QUESTION ID:24

Overexpression of protein 'A' in the brain of Drosophila melanogaster causes the degradation of ovaries in the animal. Overexpression of a secretion-incompetent allele of 'A' does not cause this phenotype. However, downregulation of protein 'B' in ovaries concomitant with overexpression of protein 'A' in the brain prevents ovary degradation. 'A' and 'B' are found to physically interact in ovary lysates. In the light of the above experiments, which of the following inferences would be correct?

QUESTION ID:25

A student used the mark-recapture method to assess the population size of grasshopper in a field. The student was asked to repeat the recapture procedure once on three consecutive days. The procedure followed by the student and the observations made are as follows:

A. On day one, 40 grasshoppers were captured , marked and released back in the field.
B. On day two, 60 grasshoppers were re-captured of which, 4 were marked. He marked the unmarked ones and released all 60 in the field.
C. On day three, 50 grasshoppers were re-captured of which 7 were marked. He marked the unmarked ones and released all 50 in the field.
D. On day four, 25 grasshoppers were re-captured of which 6 were marked. The student was asked to calculate the population size based on the mean of the three observations. The estimated population size is:

QUESTION ID:26

A cancer clinic is treating four unrelated patients suffering from chronic myelogenous leukemia. A researcher sequences the Philadelphia chromosome from the leukemic cells of these patients and makes the following statements:
A. The DNA sequence was identical in the translocation breakage and rejoining (TBR) sections in all leukemic cells in all 4 patients.
B. The DNA sequence was identical in all leukemic cells from patient 1, but every patient had a different TBR sequence.
C. All patients have translocations between long arms of chromosomes 9 and 22.
D. All patients have translocations between long arm of chromosome 9 and short arm of chromosome 22.

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

QUESTION ID:27

The names of the plant pathogens and their taxonomic groups are given in the table.


Plant pathogen

Taxonomic group

A

Phytophthora infestans

i

Bacteria

B

Cladosporium fulvum

ii

Oomycetes

C

Ralstonia solanacearum

iii

Nematodes

D

Heterodera schachtii

iv

Fungi

Choose the option with all the correct matches:   

QUESTION ID:28

The following statements are made for the effect of hormones on the glomerular filtration rate (GFR).
A. Norepinephrine, epinephrine, and endothelin constrict renal blood vessels and decrease GFR.
B. Endothelin dilates renal blood vessels to increase GFR.
C. Norepinephrine and endothelin constrict renal blood vessels and decrease GFR, while epinephrine dilates renal blood vessels to increase GFR.
D. Prostaglandin (PGE2) and bradykinin decrease renal vascular resistance and increase GFR.

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

QUESTION ID:29

The given table shows the annual Net Primary Productivity (NPP), season length, and Leaf Area Index (LAI) for various ecosystems.

Ecosystem

Season length (days)

Annual NPP (g m²)

Total LAI (m² m⁻²)

Tropical Forest

365

2482

6.0

Temperate Forest

250

1550

6.0

Tundra

100

180

1.0

Desert

100

250

1.0

Which one of the following options represents the correct order of decreasing NPP per day per unit leaf area?

QUESTION ID:30

In a hypothetical organism, at a four-celled embryonic stage, blastomere 'X' instructs one of the daughter cells of an adjoining blastomere 'Y' to take the fate 'Ya'. The other daughter cell takes the fate 'Yp'. This is illustrated in the figure below as lineages for Ya and Yp. If the X blastomere is removed, both daughter cells take up the Yp fate. 

This instruction is mediated by a paracrine factor, Pap2 secreted by X blastomere interacting with Pap5 present on the membrane of Y blastomere.

The following experimental manipulations were carried out, which involved creating partial genetically mosaic embryos in vitro and following the fate of the Y blastomere.


Which one of the mosaics will show a developmental pattern similar to that when blastomere X is removed?

QUESTION ID:31

The following statements are made about the variety of thermoregulatory mechanisms in the body.
A. Human voluntary activity is decreased in cold.
B. There is a cutaneous vasodilation by heat.
C. There is an increased secretion of epinephrine and nor-epinephrine in cold.
D. There is a decreased heat production in cold.

Choose the combination of all correct statements about thermoregulatory mechanisms.

QUESTION ID:32

A complete retroposon was cloned under the entire galactose inducible promoter. The construct, as shown below, was inserted in the yeast genome to study the transposition event. 

Some of the predicted outcomes are listed below:

A. Cells grown in presence of glucose or galactose lead to increase in copy number of the transposon.

B. The transposed copies will be same as the construct inserted in the genome.

C. The transposed copies cannot transpose further.

D. The transposed copies will not respond to either glucose or galactose in the media.


Assuming that the hypothesis is correct, choose the option that has all likely outcomes.

QUESTION ID:33

The Ran GTPase imposes directionality on transport through nuclear pore complexes (NPCs). Like other GTPases, Ran is a molecular switch that can exist in two conformational states, depending on whether bound to GDP or GTP. Possible reasons for compartmentalization of Ran-GTP accumulation are:
A. Ran-GAP is enriched in the nucleus
B. Ran-GAP is localized in the cytosol
C. Ran-GEF is enriched in the nucleus
D. The nuclear import receptors help in the compartmentalization of Ran-GTP

Which of the options below has all the correct statements about Ran-GTP compartmentalization?

QUESTION ID:34

The following gel patterns are that of DNA markers observed in parents (P1 and P2), F1 from a cross between them and doubled haploid progeny (panel A) or F2 progeny, derived from selfing of F1 (panels Band C).

A doubled haploid (DH) is a genotype formed when plants are developed from haploid cells which have undergone chromosome doubling. 
Based on the pattern observed in the DH or F2 progeny identify which of the patterns (A to C) are based on DNA markers that are allelic? 

QUESTION ID:35

In a frog species, foot webbing is controlled by a single gene where the allele for nonwebbed feet (W) is dominant and webbed feet (w) is recessive. Assume there is a population of 500 individuals, where 320 have the genotype WW, 160 have the heterozygous genotype of Ww, and 20 have the genotype ww.

What are the frequencies of the three genotypes and alleles in this population?

QUESTION ID:36

The ratio of total protein content to total RNA content was measured in yeast cells in log phase during growth in minimal media and in minimal media supplemented with amino acid cocktail. In the latter case, the ratio of protein to RNA increased dramatically. Which one of the following is a correct inference from the above information?

QUESTION ID:37

Given below are a few statements regarding the rate of glycolysis, gluconeogenesis and glycogen metabolism.
A. Increased blood glucose would decrease gluconeogenesis and increase glycogen synthesis.
B. Increased levels of fructose-1, 6-bisphosphate inhibits glycolysis.
C. Increased blood glucagon inhibits glycogen synthesis and stimulates glycogen break down.
D. Increase in AMP levels inhibits glycolysis and stimulates gluconeogenesis.

Which one of the following options represents INCORRECT statements?

QUESTION ID:38

Here is some data for a cohort of 400 individuals of a species whose abundance was tracked for 6 years (its maximum lifespan). For one-year age intervals from birth to 6 years, you have the following numbers of survivors, 400, 200, 100, 40, 20, 10, and 0. The corresponding per capita birth rates are 0.1 , 2.0, 3.0, 4.0, 4.0, 3.0, and 0.0. What is the basic reproductive rate Ro?

QUESTION ID:39

Given below are figures representing four different situations/examples of genetic and environmental (temperature) effects on plant height in two varieties of a plant species. In figures A, C and D, solid and dashed lines represent the mean values of plant height for the two varieties G1 and G2, respectively. In figure B, the solid and dashed lines overlap.

Given below are four statements explaining the four figures.

i. Plant height is influenced primarily by the genotype of the two varieties.

ii. Variation in plant height is influenced only by the temperature and genotype has no effect.

iii. Genotype and temperature collectively have an additive effect on plant height.

iv. Both genotype and environment have an effect on plant height with the two varieties responding differently to the environment.


Which one of the following options correctly matches the figures and their corresponding explanations? 

QUESTION ID:40

A propionate kinase enzyme utilizes two substrates, propionate and acetate, with Km for propionate being half that of acetate. Which one of the following options about the rate of the reaction at very low substrate concentrations is correct?

QUESTION ID:41

An ecological community is more than just the sum of the attributes of the constituent species. Which one of the following options is NOT an attribute of ecological communities?

QUESTION ID:42

The mouse homozygous null mutant for a gene bfg always dies mid-gestation. Chimeric mice made of bfg null cells and wild-type cells have healthy pups. When the developing brain of these pups is examined, they have more than two hippocampi. Closer examination reveals bfg null cells at the centre of these supernumerary hippocampi.

Which of the following inferences can correctly be drawn from this experiment?

QUESTION ID:43

Following statements are made regarding the nature of the chromosomes in bacteria.
A. Most bacterial chromosomes are circular. However, in few bacteria, linear chromosomes exist.
B. All the bacterial systems are known to have a single chromosome.
C. Some bacterial chromosomes contain enhancer-l ike elements.
D. Chromosomes in bacteria are stabilized by histone-like proteins

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

QUESTION ID:44

The table below lists nomenclatural categories in column X along with their description in column Y.


Column X

Column Y

a

 Homonym

i.

binomial name contains the same epithet for both the genus and species

b

 Tautonym

ii.

same binominal name given to a plant and an animal

c

 Basionym

iii.

original name of a taxon on which a new combination is based

d

 Hemihomonym

iv.

two or more specific or subspecific scientific names with the same spelling, but for different nominal taxa

Which of the following represents the correct sequence of matches: 

QUESTION ID:45

Given below are a few statements related to enzymes and their functions in molecular reactions.
A. Alkaline phosphatases remove 3' phosphates from DNA and RNA.
B. S1 nuclease removes single-stranded regions from partially doublestranded DNA.
C. 5' end-labelling of DNA molecules can be done by using polynucleotide kinase which transfers a 32P-labelled phosphate group to the 5' end of dephosphorylated DNA.
D. 3'-5' exonuclease activity of Taq polymerase releases the reporter from the 3' end of Taqman probes in qPCR.

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

QUESTION ID:46

Given below are four topology diagrams corresponding to different proteins. N and C denote the N- and C-terminal ends of the protein chains.

Which one of the following statements is CORRECT? 

QUESTION ID:47

The nitrogen fixing bacterium, Rhizobium /eguminosarum, isolated from the root nodules of garden pea (Pisum sativum) is cultured in a petri plate containing appropriate nutrient agar medium. A bacterial colony was picked and inoculated into a liquid growth medium to scale up the culture for the production of biofertilizer. Which one of the following statements is correct?

QUESTION ID:48

The inhibitory IKBα protein binds to the NFKB dimer and holds them in an inactive state. On TNF treatment, the IKBα protein is degraded and NFKB enters the nucleus to transactivate gene expression. Importantly, one of the transcriptional targets of NFKB is the IKBα gene itself. Together, they form a negative feedback loop. Which one of the following graphs represents the NFKB protein expression kinetics when TNF exposure is given as a pulse (a) or continuously (b)? 

QUESTION ID:49

Molecular phylogeny indicates that whales are closely related to the artiodactyls. Given this information, select the phylogenetic tree that shows the correct set of terrestrial animals with which modern whales share their most recent ancestry.  

QUESTION ID:50

Sucrose-phosphate synthase (SPS) is a key enzyme in the biosynthesis of sucrose in plants. Following are certain statements regarding SPS:
A. Uridine-diphosphate glucose and fructose-6-phosphate are the substrates for SPS.
B. SPS directly converts its substrate into sucrose.
C. Phosphorylation activates while dephosphorylation inactivates SPS.
D. SPS converts its substrate into sucrose-6-phosphate which is then converted to sucrose by the action of sucrose-phosphate phosphatase.
E. Glucose 6-phosphate activates while Pi inactivates SPS.

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

QUESTION ID:51

ABA plays an important role in plant response to water stress. In the table below, column X represents some of the important enzymes in ABA biosynthesis/degradation pathways, while column Y summarizes the major function of these enzymes.


Column X (Enzymes)

Column Y (Functions)

A.

 9-cis-epoxycarotenoid dioxygenase

i.

Involved in the oxidative pathway of ABA catabolism

B.

 Cytochrome P450 monooxygenase (CYP707A3)

ii.

Production of a sugar-conjugated form of ABA

C.

 ABA glucosyltransferase

iii.

Xanthoxin production

D.

 β-glucosidase

iv.

Releases ABA from its sugar-conjugated form

Choose the option showing the correct match between column X and column Y?

QUESTION ID:52

During physical exercise, a large amount of oxygen is delivered to the active muscles by many physiological adjustments including a change in the P50 value (which is determined by Po2 at which hemoglobin is half-saturated with oxygen). The following proposed statements explain the mechanism of change in P50 during exercise:
A. P50 is increased during exercise as the temperature rises in active muscles.
B. During exercise, metabolites accumulate in the active muscles resulting in higher pH that increases P50.
C. P50 is increased during exercise as CO2 is decreased in active muscles.
D. An increase in 2,3-DPG has been reported in non-trained person within 60 min of exercise resulting in higher P50.

Which one of the following options represents the correct combination of the above statements?

QUESTION ID:53

RPMI and DMEM, supplemented with serum, antibiotics, glutamine and phenol red are routinely used for tissue culture of human cells in CO2 incubators. In addition, sodium bicarbonate (NaHCO3) and HEPES are used as buffering agents. The following statements were made about the media.
A. While 5% CO2 is optimal for cells cultured in RPMI , the optimal CO2 concentration for DMEM is 7.5-10%.
B. HEPES is necessary if cells are to be kept outside the incubator in room air for long periods.
C. NaHCO3 is necessary if cells are to be kept outside the incubator in room air for long periods.
D. When cells grow rapidly in the culture medium for a few days, phenol red will turn the medium pink/red .

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