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Previous Year Questions

TLS Online TPP Program

QUESTION ID:1

The chart shows forest cover as percentages of total areas of 6 countries over the period 1990-2022 and their land areas {in million km2) . 
The maximum change in forest area in absolute terms among these countries took place in

QUESTION ID:2

A group of 54 boys and girls was made to stand in a queue as follows: a boy at the start was followed by a girl, then a boy followed by 2 girls, then a boy followed by 3 girls, and so on. The number of boys in the group was

QUESTION ID:3

Suppose liars always lie and truthful persons never. In a group of 4 people A, B, C and D, A says, "We're all liars", B says, "Only one of us is a liar", C says, "No, exactly two of us are liars" and D says, "I'm truthful". Which among the following is definitely FALSE?

QUESTION ID:4

Among five girls standing side by side, Leela has exactly one girl to her left, Alice is just right of Prerna, and there are at least two girls between Radha and Zarina. The girl in the middle is

QUESTION ID:5

A spherical object of radius 6 cm was melted and cast into a cylindrical bar of radius 3 cm. What would be the length (in cm) of the bar?

QUESTION ID:6

A ball starts rolling from the edge of the slope at time t = o as shown in the diagram.

QUESTION ID:7

A 1 m long rod having diameter of 12 mm weighs 880 g. What, approximately, is the density (in g/cm3} of the material of the rod?

QUESTION ID:8

Consider the first few consecutive natural numbers. The ratio of the sum of their squares to their sum can NEVER be

QUESTION ID:9

A straight irrigation canal in a plain area has a floor at a depth of 5 m from the surface. The canal is 20 m wide at the surface. The floor of the canal Is flat and the embankments have a slope of 45°. When it is completely filled, what will be the volume of water (in m3) in the canal over a length of 100m?

QUESTION ID:10

A record player stylus moves along a spiral groove cut on an annular portion of a disc. A record with inner radius 4 cm and outer radius 10 cm of the annulus, turning 100 times plays for 22 minutes. During this time the stylus travels at an average linear speed that is approximately equal to

QUESTION ID:11

Choose the option that will make the following statement FALSE:

A CHILD COUNTED THE NUMBER OF APPEARANCES OF THE LETTER T IN THIS SENTENCE,AND REPORTED IT CORRECTLY AS ________

QUESTION ID:12

If X > Y > 0 , then X % of Y is

QUESTION ID:13

For any four consecutive decimal digits, the largest value of the product of the sum of any two and the sum of the other two is

QUESTION ID:14

The growth model for a population is
                                                              Nt = N0 ert
where Nt is the population at time t, N0 is the initial population and r is the per capita growth rate. How long does it take for the population numbers to double?

QUESTION ID:15

The total monthly income of a family is split into expenses on food (F), house rent (H), college fees (C), entertainment (E), miscellaneous items (M), and savings (S), as shown in the pie chart. 
The family transfers an amount of Rs 1000/- from the head food to the head entertainment, thereby making the expenses on the two heads equal. What is the net expenditure of the family?

QUESTION ID:16

The graph shows average run rate (runs scored per over) by teams A and B in a twenty overs cricket match.
Select the INCORRECT statement.

QUESTION ID:17

A certain item of raw food contains 35% starch, 25% protein, the rest fibre. The item is cooked by boiling in water, which doubles its weight. Half of the fibre in the food becomes soluble when cooked. If the cooked item weighs 200g, the amount of soluble fibre in it is

QUESTION ID:18

If 16x2 - 25y2 + 7 = 0, x and y being positive numbers, then which of the following may hold?

QUESTION ID:19

In humans, if both parents are of blood group AB, then, there is a 1/4 probability that their offspring will be of blood group A, and 1/2 probability that the offspring will be of blood group AB. If the couple have three children, what is the probability that NONE of the children will be of blood group A or AB?

QUESTION ID:20

Every element in the central column of the matrix has a simple arithmetic relationship with the pairs on the left and right in the corresponding row.

What would be the value of x ? 

QUESTION ID:21

Retinal rod cell cGMP-phosphodiesterase is an enzyme with subunit structure as:

QUESTION ID:22

Which one of the following statements regarding plasmodesmata in a plant cell is INCORRECT?

QUESTION ID:23

In animal cells, typically which organelle is only provided by the sperm to the oocyte following fertilization?

QUESTION ID:24

In Caenorhabditis elegans, blastomere identity occurs both through conditional and autonomous modes of cell specification. Which one of the following options is a correct statement in this regard?

QUESTION ID:25

Given below are Ramachandran plots for four different proteins.

Choose the correct pair of proteins, both of which are predominantly alpha helical in nature.

QUESTION ID:26

In the representation of the di-peptide shown below, the superscript '-1 ' denotes the atom of the previous amino acid while '+1 ' denotes the atom of the next amino acid.
The atomic coordinates of how many and which of the following atoms are required to uniquely define the torsion angles, Φ and Ψ of the Ramachandran plot?

QUESTION ID:27

Which one of the following options has the correct set of components for assaying reverse transcriptase activity?

QUESTION ID:28

Which one of the following options includes all plants that are major non-native invaders of aquatic ecosystems in India?

QUESTION ID:29

In which one of the following stages pontogeniculo-occipital (PGO) spikes are found in human EEG recordings?

QUESTION ID:30

Which one of the following represents the predominant 'source organ' during phloem translocation in healthy plants?

QUESTION ID:31

The following are sketches of wild-type and mutant (I - Ill) embryos of Drosophila  melanogaster.

Which one of the following options represents a correct match between the gene and its loss of function phenotype?

QUESTION ID:32

Which one of the following statements regarding mammalian innate immunity is INCORRECT?

QUESTION ID:33

Which one of the following is an example of dishonest signaling?

QUESTION ID:34

If chimeric mouse embryos were generated using GFP-expressing embryonic stem cells and RFP-expressing induced pluripotent stem cells, which one of the following tissues from any resulting embryos will not express any fluorescent protein?

QUESTION ID:35

Which one of the following activities is associated with Mitochondria-associated ER membranes (MAM)?

QUESTION ID:36

Which one of the following pairs correctly matches the enzyme with its allosteric activator?

QUESTION ID:37

Cell lysate in 1 % TX100 was purified over an affinity column to isolate a complex with certain enzymatic activity. The purified enzyme complex was separated on a 10-50% continuous sucrose gradient. Shown below are the UV spectra using an absorbance filter at 280nm or 260nm.

Which one of the following combinations of molecules would generate the spectra shown above?

QUESTION ID:38

Select the correct combination of terms from plant breeding systems that represents selfing or promote selfing. 

QUESTION ID:39

In rate-zonal centrifugation, a mixture is spun just long enough to separate molecules that differ in mass but may be similar in shape and density. Which one of the following options represents the component that is typically used to create a gradient in this technique?

QUESTION ID:40

Which one of the following statements regarding the structure of water molecule is correct?

QUESTION ID:41

Which of these traits is NOT characteristic of r-selected tree species?

QUESTION ID:42

A community of woody plants is being shaped by environmental filtering. What will be the likely local species pool of this community, if the regional species pool comprises 60 species? 

QUESTION ID:43

Which one of the following statements about the cortical reaction in sea urchins is correct?

QUESTION ID:44

Select the geological time where some of the major events, like an increase in marine diversity, dominance of gymnosperms, diversification of synapsids (including the emergence of first dinosaurs), and first mammal-like forms, occurred.

QUESTION ID:45

Which one of the following neurotransmitters is synthesized in synaptic vesicles instead of being transported to the vesicle after its synthesis in the cytoplasm?

QUESTION ID:46

A plant is NOT watered for seven days (day 1 - day 7). Leaf and root water potential are measured every two hours starting from day 1 till day 7. Which one of the following is LEAST LIKELY to happen?

QUESTION ID:47

Which one of the following statements correctly explains the function of a GTPase activating protein (GAP) in the regulation of heterotrimeric G proteins in plants?

QUESTION ID:48

For maintaining hydraulic conductance, tree stems appear to trade-off vessel diameter with 

QUESTION ID:49

Which of the following is LEAST suited for long-distance phloem transport of photo-assimilated carbon in plants?

QUESTION ID:50

Who experimentally demonstrated "Mutations occur randomly"?

QUESTION ID:51

Which one of the following statements for the lac operon in E. coli is INCORRECT?

QUESTION ID:52

A researcher overexpresses the full-length genomic sequence of rice GAPDH gene under a CaMV35S promoter in transgenic rice. Which one of the following options can be used to confirm transgenic lines using PCR?

QUESTION ID:53

In eukaryotic cells, DNA replication is restricted to the S phase of the cell cycle because

QUESTION ID:54

Which one of the following correctly describes 'Dark Reversion' of phytoch romes?

QUESTION ID:55

It was found that most people who were vaccinated with the ancestral strain of Covid-19 (Wuhan strain) were protected against the Delta variant but not against the Omicron variant. PBMCs (peripheral blood mononuclear cells) and serum were obtained from five successfully vaccinated individuals with good neutralizing antibody titres and cytotoxic (CTL) activity against the Wuhan straininfected targets. Pooled serum was transferred into unrelated recipient "A" and pooled purified T cells were transferred into unrelated recipient "B". Which one of the following is likely to be observed?

QUESTION ID:56

Select the statement that describes guild coevolution, also known as diffuse coevolution.

QUESTION ID:57

In 2007, scientists reported the fossil of a deer-like animal in Kashmir, India which is considered the most recent terrestrial ancestor of whales. The name of this fossil is

QUESTION ID:58

Brassica Juncea has bisexual flowers.
A mutation in the mitochondria leads to cytoplasmic male sterility (CMS). CMS can be restored by a restorer of fertility gene (Rf) which is a nuclear gene.
Fertility restoration is a dominant phenotype.
A CMS line is crossed to a homozygous Rf line. The obtained F1 progeny is selfpollinated. What percentage of F2 progeny will be male sterile?

QUESTION ID:59

Andaman and Nicobar archipelago are part of which biodiversity hotspots?

QUESTION ID:60

Which one of the following does NOT occur during ribosome-associated quality control of damaged mRNA?

QUESTION ID:61

A student counts the number of seeds produced by ten different haploid Arabidopsis plants and obtains the following data:

0, 5, 15, 25, 100,150, 200, 600, 1500, 3000.

Which one of the following is the best measure of central tendency for summarizing the above data?

QUESTION ID:62

How many amino acids are present in calcitonin, a calcium lowering hormone synthesized from C-cells of the human thyroid gland?

QUESTION ID:63

What is the correct order in which the following proteins are recruited during DNA double strand break repair in prokaryotes?

QUESTION ID:64

Which one of the following statements regarding principles of linkage mapping in plants is correct?

QUESTION ID:65

How many times are sound waves amplified in the middle ear of a human?

QUESTION ID:66

Which one of the following concepts can explain host-parasite co-evolution?

QUESTION ID:67

Which one of the following is a correct combination of four carbon intermediates formed during C4 photosynthesis in plants?

QUESTION ID:68

In eukaryotes, nucleosome remodelers

QUESTION ID:69

A DNA molecule is completely transcribed into messenger RNA by an RNA polymerase. The base composition of the DNA template strand is G = 24. 1 %; C = 18.5%; A = 24.6%; T = 32.8%. The base composition of the newly synthesized RNA molecule is:

QUESTION ID:70

A pulse oximeter measures the ratio between oxyhemoglobin and hemoglobin in the pulsating condition on the finger. Which combination of wavelengths can obtain a differential absorption to measure blood oxygen saturation?

QUESTION ID:71

Some features mentioned below are important for the segregation of homologous chromosomes in meiosis I.
A. Synaptonemal complex formation between homologous chromosomes.
B. Degradation of cohesins at the chromosome arms.
C. Retention of cohesins at the centromeres.
D. Bi-orientation of kinetochores of sister chromatids.

Which one of the following options has all correct features?

QUESTION ID:72

A KDEL sequence is added at the C-terminus of a secreted glycoprotein X (500 amino acid residues) having no site for N-linked glycosylation and expressed from an inducible promoter. Following 10, 20 and 60 minutes of induction, ER are purified and probed for newly synthesized glycoprotein X-KDEL. The immunoblot obtained is shown below.


Which one of the following statements is the most likely explanation for presence of the higher molecular weight bands in lanes 20 and 60 minutes?

QUESTION ID:73

The statements below are about possible genetic relatedness between individuals of a monogamous, haplodiploid insect.
A. A female is related to its son by 0 .5
B. A female is related to its brother by 0.5
C. A male is related to its mother by 1
D. A male is related to its daughter by 1

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

QUESTION ID:74

The following statements represent possible outcomes of competition between two species.
A. Niche differentiation between species
B. Expansion of fundamental niche of both species
C. Expansion of realized niche of both species
D. Character displacement between species

Which one of the following options represents the correct set of possible outcomes?

QUESTION ID:75

In order to investigate the involvement of the following proteins in the mismatch repair mechanism (MMR), an in vitro reconstitution experiment was performed. A 5'-nicked circular DNA substrate having a C:C mismatch at the Pstl site was incubated with different combination of proteins (as shown below), where upon the repair of C:C mismatch, the Pstl site will be regenerated. Following the incubation, the resulting DNA were digested with Pstl and Seal restriction endonucleases, and the products were electrophoresed in 0.8% agarose gel. 
Based on the results obtained identify the INCORRECT statement.

QUESTION ID:76

Given below are some components that could potentially influence membrane fluidity.
i. Monomeric G-proteins
ii. Peripheral membrane proteins
iii. Sphingolipids
iv. Phospholipid sidechain saturation
v. Cholesterol

Choose the option that has all the components that can influence membrane fluidity.

QUESTION ID:77

Which one of the following options represents a classical Hoogsteen base pairing?

QUESTION ID:78

Given below are protein domains and their binding specificities.


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

QUESTION ID:79

For the coupled reaction given below, the equilibrium constants (K'eq) for equation (1) and equation (2) are 270 and 890, respectively.

Glucose 6-phosphate + H2O âž” glucose + Pi (1]
ATP + glucose âž” ADP + glucose 6-phosphate (2)

The standard free energy of hydrolysis of ATP at 25°C is

QUESTION ID:80

Given below are a few statements on concepts of molecular breeding.
A. Correlations between quantitative traits can be because of pleiotropic effects of the same gene and/or genetic linkage of genes associated with the traits.
B. In a Recombinant Inbred Line (Rll) population, genetic segregation of both dominant and codominant markers occurs in a 1: 1 ratio.
C. Near isogenic lines (Nils) can be produced by repeated backcrossing of the F 1 to a recurrent parent.
D. SNPs are dominant markers.

Which one of the following options represents all correct statements?

QUESTION ID:81

A plant breeder plans to introgress a gene for pathogen resistance (R) from a wild species (B) into a cultivated variety (A). Panel I in the figure shows a profile of DNA markers for A and B. Panel II shows a genetic map for the linkage group which has the gene for pathogen resistance. 
Which one of the following options has the correct choice of markers for foreground (FG) and background (BG) selection, respectively?

QUESTION ID:82

One hundred lgM+ B cells were plated at 1 cell/well and activated in vitro. This led to detectable proliferation in all wells by day four. At the end of seven days, it was found that some wells contained lgG1 antibodies, some contained both lgG1 and lgA antibodies, and some contained only lgA antibodies. The following interpretations were made:
A. Cells that have switched to lgG1 may undergo further switching to lgA.
B. Cells that have switched to lgA may undergo further switching to lgG1.
C. A single cell can simultaneously secrete lgG1 and lgA.
D. The progeny of proliferating cells may undergo independent switching events.

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

QUESTION ID:83

The types of mammalian nerve fibers (Column X) and the conduction velocity in mis of nerve impulses (column Y) are listed below:

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

QUESTION ID:84

Four groups of students (A - D) were asked to determine whether memory B cells generated in mice immunized with ovalbumin (OVA), in Complete Freund's adjuvant (CFA), could mount a secondary antibody response (recall response) to OVA in vitro. The groups did the following experiments:
Group A students harvested serum from the mice, loaded it on OVA-coated ELISA plates and showed that lgG and lgA anti-OVA antibodies were present.
Group B students harvested long-lived plasma cells from bone marrow of themice, plated them in culture for 5 days and showed anti-OVA antibodies in supernatant by ELISA.
Group C students infected an epithelial cell line with the virus and showed that spleen cells from the mice could kill the infected targets.
Group D students stimulated spleen cells from the mouse with OVA for 5 days and showed anti-OVA antibodies in supernatant by ELISA.

Which one of the following options represents group(s) that did the correct experiment?

QUESTION ID:85

A researcher was interested in detecting parasite-derived antigens in Plasmodium falciparum-infected erythrocytes. The following labelling experiments were performed, followed by immunoprecipitation with antibodies against P. falciparum proteins and autoradiography.
A. Labeling with 32P-ATP in the media
B. Labeling with 125Iodine in the media
C. Labeling with 35S-Methionine in the media
D. Labeling with 3H-Hypoxanthine in the media

Which one of the following options represents labeling experiments to predominantly detect the parasite-derived antigens?

QUESTION ID:86

Cystic fibrosis is caused by a recessive allele. Roughly one out of every 500 individuals (0.20%) have this disease. Using the Hardy-Weinberg equation, the percentage of individuals who are carriers of the recessive allele for the disease is

QUESTION ID:87

In vivo interaction between FLAG-tagged protein P and chaperone H was examined by co-immunoprecipitation (co-IP). Co-chaperone A was included and the co-IP was performed in the presence or absence of cycloheximide (CHX). The results of the co-IP experiments are shown below. 
Which of the following interpretations from these experiments is INCORRECT?

QUESTION ID:88

Biosynthesis of glutamine and asparagine is sensitive to light and to the availability of reduced carbon. Following are a few statements regarding the same.
A. Expression of the plastid-localized Glutamine Synthetase ( GS) gene is upregulated by light.
B. Darkness promotes the expression of Asparagine Synthetase (AS) gene.
C. Expression of GS is inhibited by sucrose while that of AS is upregulated by sucrose.
D. Asparagine is a more efficient carbon source than glutamine.

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

QUESTION ID:89

Following are certain statements regarding Crassulacean Acid Metabolism (CAM) plants:
A. The HC03- concentration is enriched in the cytosol during night by the CO2 coming from the external atmosphere through the open stomata and the mitochondrial respiration.
B. Oxaloacetate produced by the action of PEPCase is stored in the vacuole during dark.
C. During light, oxaloacetate produces malate that provides CO2 for CalvinBenson cycle in the chloroplast.
D. During dark, phosphoenolpyruvate is produced by the breakdown of starch present in the chloroplast.
E. CAM is a mechanism of concentrating CO2 around Rubisco by keeping stomata closed during day.

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

QUESTION ID:90

Select the option that correctly identifies the three labelled floral parts in the floral diagram of a grass flower:

 

QUESTION ID:91

DNA polymerase PolA has high fidelity but low processivity and DNA polymerase PolB has low fidelity and high processivity. In vitro reactions for DNA synthesis using limiting amount of PolA or PolB were set to further characterise the enzymes according to the following scheme: 

Which of the following outcome do you expect?

QUESTION ID:92

The CDS of the shortest isoform of human gene 'A' is cloned into a 3.3 kb vector under a CMV promoter at the BamHI and Xhol sites (pCMV-A vector).  

From the agarose gel and SOS-PAGE images shown above, which one of the following is most likely true for protein A in Hela cells:

QUESTION ID:93

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:94

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:95

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:96

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

QUESTION ID:97

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

QUESTION ID:98

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:99

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:100

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:101

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:102

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:103

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:104

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


QUESTION ID:105

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

 

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

QUESTION ID:106

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

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

QUESTION ID:107

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

QUESTION ID:108

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:109

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:110

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:111

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:112

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:113

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:114

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:115

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:116

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:117

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:118

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:119

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

Choose the option with all the correct matches:   

QUESTION ID:120

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:121

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

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

QUESTION ID:122

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:123

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:124

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:125

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:126

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:127

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:128

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:129

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:130

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:131

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:132

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:133

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:134

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:135

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:136

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

Which of the following represents the correct sequence of matches: 

QUESTION ID:137

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:138

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:139

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:140

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:141

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:142

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:143

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.

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

QUESTION ID:144

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:145

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?