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Previous Year Questions

TLS Online TPP Program

QUESTION ID:1

Two new chemical compounds X and Y are synthesized in a laboratory and tested for their potency as a mutagen. The nature of the mutation produced by these compounds Is tested for reversal by other known mutagens and the following results were obtained:

QUESTION ID:2

Following statements were made about cell cycle regulation in eukaryote&:
A. Activity of maturation promoting factor (MPF) rises and falls in synchrony with the concentration of cyclin B.
B. Cdc25 phosphatase mediates removal of phosphate from the inhibitory tyrosine residue (Y15) to yield highly active MPF.
C. MPF specifically phosphorylates and depolymerizes lamin A and C, but not lamin B.
D. MPF phosphorylate& Hl histone.
E. In Schlzosaccharomyces pombe, overproduction of Weal protein decreases the length of G2 phase and extends the period
of M phase by functioning as a mediator of MPF activity.
Which one of the following represents the combination of correct statements?

QUESTION ID:3

If the weights of 10,000 seeds from 100 individuals of a tree species are measured, which one of the following distributions is expected?

QUESTION ID:4

Following statements were made to explain the Intracellular transport that occurs through apoplastic, simplistic and transcellular routes in plants:
A. Apoplectic transport mostly occurs through cell-wall.
B. Apoplectic transport mostly involves plasmodesmata.
C. Simplistic transport predominantly occurs through plasmodesmata.
D. Transcellular transport mostly occurs through tonoplast via vacuoles.
Which one of the following combination of statements is correct?

QUESTION ID:5

The Initiation of transcription Is a complex process Involving promoter recognition, conversion of the Initiation complex from closed to open form, abortive initiation events, and finally promoter escape. The following statements are made regarding these steps In transcription Initiation:
A. Promoter escape in bacteria is usually accompanied by the release of the sigma factor from the RNA polymerase holoenzyme complex.
B. Abortive initiation events in prokaryote& result in the formation of short transcripts "'10 nudeotides in length while such events in eukaryote& result in formation of transcripts 75 nucleotides in length.
C. Promoter escape in eukaryotes is accompanied by the phosphorylation of the RNA polymerase large subunit on its c- terminal domain (CTD).
D. Promoter recognition in bacteria is governed by the sigma factor which binds to the -10 and -35 regions of the promoter followed by recruitment of the RNA Pol II core enzyme to form the holoenzyme.
Which one of the following options represents the combination of all correct statements?

QUESTION ID:6

A number of statements have been made regarding heme, a component of hemoglobin, as given below:
A. It is synthesized in mature erythrocytes
B. It is synthesized by the condensation of succinyl-CoA and glycine
C. It is synthesized by the condensation of acetyl-CoA and glycine
D. Its synthesis is catalyzed by 8 amino levulinate synthase
Which one of the following combinations has both INCORRECT statements?

QUESTION ID:7

A human subject can voluntarily Inhibit respiration for some time but the subject feels Irresistible urge to resume breathing after a while at a point which is called the breaking point. The characteristic features of breaking point are suggested in the following statements:
A. The breaking point is shorter in subjects after removal of carotid bodies compared to when they have intact carotid bodies.
B. The breaking point is prolonged if the subject breathes 100% oxygen before breath holding.
C. When the subject hyperventilates with room air before breath holding, the breaking point Is delayed compared to when the subject breathes normally before breath holding.
D. The breaking point can be reduced In a subject by making respiratory movements behind a closed glottis.
E. The breaking point is shorter when the subject is told during breath holding that her/his performance is very good compared to a situation when she/he is not told so.
Choose both the correct statements from the following options:

QUESTION ID:8

Protein 'A' was subjected to different experiments:
I) SD5-PAGE with/without 11-mercaptoethanol (11-ME) II) Fluorescence Ill) Far-uv and lv) Near-uv CD spectra at pH 7.0 (blue) and 3.0 (red)
The results are shown below:
Which one of the following options provides the correct Inference?

QUESTION ID:9

Although introns are not a part of the processed transcript that gets translated, they are important for several reasons. The
following statements are made with reference ta the possible ways In which lntrons are crucial to cell survival.
A. They permit the generation of different protein products from the same gene.
B. They may encode miRNAs which modulate the expression of genes.
c. They often encode peptides which play a role in regulating gene expression.
D. They promote export of certain mRNAs through the recruitment of transport proteins by the Exon Junction Complex (EJC).
E. They play a role In mRNA surveillance through the modulation of nonsense-mediated mRNA decay via the Exon Junction Complex (EJC).
Which one of the following options represents the combination of all correct statements?

QUESTION ID:10

The Interactions that maintain polarity during Plana ria regeneration Is shown In the figure below:

Following statements regarding these Interactions were made:
A. When Notum expression is knocked down, the anterior facing blastema will still form a head.
B. When Notum Is expressed In the posterior end, Plana ria with two heads will be formed.
c. When Wnt pathway is blocked, the resulting Planaria will have heads on both the ends.
D. High levels of Erk Inhibit head specification.
Which one of the following options represents the correct combination of the statements?

QUESTION ID:11

Glycolysis and citric acid cycle contribute precursors to many biosynthetic pathways in plants. Column X lists names of the precursors and column Y lists the product synthesized.
Which one of the following options represents the correct match between column X and Y?

QUESTION ID:12

The graph below depicts trajectories (A to D) of some of the major drivers of global environmental change (i to iv) that are mentioned alongside.
Match the trajectories with the correct drivers:

QUESTION ID:13

The following statements were made about adaptive radiation:
A. Adaptive radiation Is a kind of divergent evolution driven by ecological diversification.
B. Adaptive radiation is the divergence of unrelated taxa into different niches.
C. Adaptive radiation Is rare on archipelagos removed from the mainland.
D. Processes unrelated to niche exploitation can be major drivers of species diversification
Choose the option that represents all correct statements

QUESTION ID:14

Following are the statements made about major functions of some of the neuroglia in normal condition:
A. Oligodendrocytes help maintain K+ level, and contribute to the blood-brain barrier.
B. Microglia are capable of movement and phagocytosis of pathogens and damaged tissue.
c. Astrocytes produce the myelin sheath to electrically insulate neurons of the CNS.
D. Ependymal cells which are ciliated are Involved In circulation of cerebrospinal fluid.
Which of the following options represents the combination of all INCORRECT statements?

QUESTION ID:15

The hemagglutinin protein in influenza virus contains a long a-helix, with 53 residues. Which of the following correctly describes the attributes of this a helix?

QUESTION ID:16

Column (A) lists enzymes involved in cell cycle and typical function in a particular cell cycle phase is listed in Column (B).

Which one of the following options represents the correct match between column A and column B?

QUESTION ID:17

Given below are the list of proteins (Column X) and their functions (Column Y) during floral induction.

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

QUESTION ID:18

Different waves of EEG (Column A) are listed with their frequencies (Column B) below.

Choose the option with all correct matches of the wave with its frequency

QUESTION ID:19

Young seedlings of Arabidopsis plants are exposed to the following light conditions:
A. Far-Red light followed by Red light
B. Far-Red light followed by Red light and then Dark phase
c. Red light followed by Far-Red light
D. Dark phase followed by Far-Red light and then Red light
E. Far-Red light followed by Dark phase and then Red light
F. Red light followed by Dark phase and then Far-Red light
Which of the above conditions will lead to photomorphogenesis?

QUESTION ID:20

Which one of the following statements is NOT correct?

QUESTION ID:21

A 'nonsense' mutation In the protein coding region of an upstream gene of a group of genes In an operon often leads to depletion of the downstream gene products. This is a classic example of the phenomenon of " polar effect" of the mutation. Following statements are being made about this phenomenon.
A. It occurs primarily because the termination codon generated in the upstream open reading frame (ORF) leads to termination of protein synthesis depleting the ribosomes for translation of the downstream ORFs but it does not affect the process of transcription.
B. The phenomenon of polar effects of mutation occurs only in the operons where the point mutation leading to creation of nonsense' mutation also leads to formation of a stem-loop structure resulting in Rho-independent termination.
C. While the presence of termination codon in the upstream ORF may deplete the ribosomes that travel down to the downstream ORF, the depletion of ribosomes downstream of the 'nonsense' mutation allows loading of the Rho factor that then results in premature transcription termination.
D. Presence of the suppressor tRNA reading the 'nonsense' codon generated by the mutation, is essential for causing a polar effect of the mutation.
E. Presence of the suppressor tRNA reading the 'nonsense' codon generated by the mutation diminishes the consequences of the polar effects.
Choose the option that represents all correct statements

QUESTION ID:22

The graphs (A-C) below depict the seasonal variation In plankton biomass in three oceanic regions of Northern hemisphere (i to iii):
Oceanic regions of the world:
I. Tropical oceans
ii. Polar oceans
Ill. Temperate oceans
Match the graphs (A to C) to the correct oceanic region (i to iii).

QUESTION ID:23

Which one of the following statements In relation to Insect wings Is NOT true?

QUESTION ID:24

A researcher examined the features of newly hatched birds. Species A showed open eyes, down feathers and was able to move around. Species B lacked down feathers and was incapable of walking and its eyes were closed. Given this, choose the correct option

QUESTION ID:25

The following are a set of characteristics found In the animal kingdom:
A. The body is usually streamlined. Some have spindle-shaped or elongated body.
B. The body Is covered with thick-seated scales, which provides protection to the Internal organs.
c. They may be herbivores or carnivores, oviparous or ovoviviparous.
D. The nervous system comprises of the brain and ten pairs of the cranial nerves.
E. All of them are oviparous and exhibit sexual dimorphism.
Select the correct set of characterizing features for the Class Pisces

QUESTION ID:26

The Immune system or thymectomized and lethally Irradiated (A X B) F1 mice (H-2•/b) were reconstituted by grafting thymus from Strain B mice (H-2b) and with (A X B) F1 bone marrow cells. These mice were then infected with lymphocytic choriomeningitis virus (LCMV). The CDS+ cytotoxic T lymphocytes from the reconstituted mice were then co-cultured with the following cells:
A. Uninfected fibroblast cells from (A X B) F1 mouse
B. Uninfected fibroblast cells from strain-A mouse
c. Uninfected fibroblast cells from strain-a mouse
D. LCMV infected fibroblast cells from (A X B) F1 mouse
E. LCMV infected fibroblast cells from strain-A mouse
F. LCMV infected fibroblast cells from strain-B mouse
Which of the options below indicate the cells that will be lysed by the CDS+ cytotoxic T lymphocytes from the reconstituted mice

QUESTION ID:27

Following statements are made about some of the abnormally expressing proteins In human cancers:
A. Increased telomerase expression always contributes to increased cell death in cancer cells.
B. Overproduction of anti-apoptotic protein (Bell) can lead to inappropriate cell survival and is associated with chronic lymphoblastic leukemia (CLL).
c. The ES, E6 and E7 proteins encoded by human papilloma virus (HPV) are tumor suppressors.
D. Overexpression of cyclin Dl or loss of p16 and Rb can cause inappropriate, unregulated passage through the restriction point in late Gl.
Which of the following options represents the combination of all correct statements?

QUESTION ID:28

Regulation of mRNA translation is a major mechanism that maintains stoichiometric availability of ribosomal proteins (rproteins) to rRNA molecules they bind to. Translational regulation is facilitated by general occurrence of the r-protein genes in several operons containing multiple genes. Which one of the following represents an established mechanism to ensure optimal production of the r-proteins in E. coli, when the r-proteins accumulate in free form (molar excess over rRNA)?

QUESTION ID:29

The figure below depicts a hypothetical scheme for synthesizing a target product in plants. A, B and C are the precursors of a target product D whereas E is a by-product. The key enzymes of the pathway are Indicated as El-E6. To enhance the levels of target product D , following strategies were tested:
A. Enhancing the activity of the enzyme E5 by over-expression and/or protein engineering.
B. Enhancing the activity of the enzyme E4 by over-expression and/or protein engineering.
C. Enhancing the levels of ©.
D. Blocking the activity of E& by RNA-interference or CRISPR/Cas-mediated knockout.
Which of the above mentioned strategies are likely to provide the maximum enhancement of the target product compared to the by-product, if no feedback regulation exists for any of the enzymes in the pathway?

QUESTION ID:30

Given below are a few statements about plant breeding and transgenesis:
A. Recombinant inbred lines and double haploid populations have high levels of genetic homozygosity.
B. Gene pyramiding Involves Introducing different genes for resistance to a specific pest In different genotypes of a plant species.
C. Agrobllcterium strains with a disarmed Tl plasmid do not require vir genes for transfer of T-DNA.
D. Molecular breeding can be used for crop improvement if the trait of interest is present in naturally occurring populations of the plant.
Which one of the following options represents a combination of INCORRECT statements?

QUESTION ID:31

Following statements were made about some of the characteristics of the human genome:
A. Evidence derived by chromosome conformation capture (3C) suggests that each chromosome comprises a series of topologically associated domains.
B. Insulators typically mark the boundaries of topologically associated domains, preventing the genes within a domain from being influenced by the regulatory modules of an adjacent domain.
C. Presence of Insulators does not overcome the positional effect after Integration of a transgene Into the genome.
D. Insulators can provide barrier against the spread of heterochromatin.
E. Insulator sequences are absent In the Drosophila genome, which suggests their essentiality In achieving highest degree of gene regulation in humans.
Which one of the following represents the correct combination of above statements?

QUESTION ID:32

Which one of the following statements best describes Bateman's principle?

QUESTION ID:33

An Individual is heterozygous for a reciprocal translocation as shown below in the given diagram:

The following statements are made about segregation of such chromosomes during meiosis and gamete formation:

A. The complexly paired 4 chromosomes fail to segregate, pass into one cell at anaphase I and the cell eventually dies.

B. Chromosomes pair between regions of maximum homology keeping the translocated part unpaired and a normal meiosis occurs.

C. One of the ways the chromosomes segregate is by alternate segregation (N1, N2 moving to one pole and T1, T2 moving to the other pole).

D. Alternate segregation produces non-viable gametes.

E. Reciprocal translocation& are considered as crossover suppressors as no gametes with crossover product are produced.

Select the option from the following that describes the meiotic consequences of such translocation correctly:

QUESTION ID:34

The following table enlists different ways of carrying out reverse genetics (Column X) and different strategies to achieve the same (Column Y).
Which one of the following options is a correct match between Column X and Y?

QUESTION ID:35

Individuals belonging to the fossil genera Calamites are considered to be upright arborescent plants. They were characterized by stems which mostly arose from subterranean rhizomes. The cross sections of young stems showed the presence of a central pith canal and collateral vascular bundles with carinal canals. To which of the following extant genera is this plant most similar?

QUESTION ID:36

The table below lists the characteristics of specific tumor types (Column A) and their names (Column B).

Which of the following options represents the correct match between Column A and Column B?

QUESTION ID:37

Following are a few statements about India's biodiversity:
A. India has 2.4% of the world's land area, but accounts for 12% of all recorded species.
B. India has over 45,000 species of animals and 91,000 species of plants.
C. Four of the globally identified biodiversity hotspots can be found in India.
D. India is estimated to harbour around 60% of the global tiger population.
Which one of the following options represents all correct statements?

QUESTION ID:38

The signal transduction pathway involved in glycogen metabolism triggered in the liver by the hormone epinephrine Involves the following steps:
A. Activation of G protein by the activated receptor
B. Protein kinase A activation
C. Second messenger generation {3',5' cyclic AMP)
D. Adenylyl cyclase activation
Which one of the following combinations describes these processes In the right order?

QUESTION ID:39

The diagram below depicts the generalized distributional curves (A to D) of allochthonous organic matter and autochthonous production by different autotrophic groups, as a stream transitions to a river.
The following are sources of organic matter:
I. Allochthonous
ii. Autochthonous from phytoplankton
Ill. Autochthonous from bottom attached algae
iv. Autochthonous from aquatic macrophytes
Choose the correct option that matches the distributional curves (A to D) to the sources (I to lv):

QUESTION ID:40

Following statements are made regarding glycogen phosphorylase and glycogen synthase activities in relation to their phosphorylation status:
A. Phosphorylation of glycogen phosphorylase increases its activity
B. Phosphorylation of glycogen phosphorylase decreases Its activity
c. Phosphorylation of glycogen synthase increases its activity
D. Phosphorylation of glycogen synthase decreases Its activity
Which one of the following is a combination of correct statements?

QUESTION ID:41

The following represents sequences of different alleles of a gene found in a family represented by mother (allele I/ allele2), father (allele1/allele 2) and their two sons: Son1 (allele1/allele 2) and Son 2 (allele1/allele2). Further, a new mutation was observed in one of the alleles of the son, which is marked with a triangle.
The following statements were made about the mutation:
A. The mutation arose in the germline of the father.
B. The mutation arose In the son.
c. The given DNA sequences are present on the X chromosome.
D. There Is a possibility to use RFLP for tracking this variation.
Which one of the following options presents a combination of correct statements?

QUESTION ID:42

Given below Is a pedigree Indicating a pattern of Inheritance:

The following statements are drawn from the above pedigree towards understanding the pattern of Inheritance:

A. An affected male does not appear to pass the trait to his sons

B. An affected male appears to pass the allele to a daughter who Is unaffected

c. All affected individuals have at least one affected parent

D. The given trait appears to be a recessive one

E. The given trait appears to be an autosomal recessive one

Select the option from the following that has all correct statements:

QUESTION ID:43

The diagrams A-D below shows the relative abundance of major groups of plants (refer to legend) In four different geological periods (Devonian, Carboniferous, Tertiary and Cretaceous).
Match the diagrams (A to D) with the correct geological period.

QUESTION ID:44

Given below is a schematic representation of the T-DNA region of a binary vector used for genetic transformation of plants

LB: Left Border, RB: Right Border, M: Marker gene, P: Passenger gene, pA: poly-adenylatlon signal, Pr1: Promoter of M gene,

Pr2: Promoter of P gene, E: Restriction enzyme (sites) used for digestion of genomic DNA for Southern blotting, Probe 1 and

Probe 2: probes used for Southern blotting.

Transgenic plants generated using the above construct were subjected to Southern hybridization following digestion of genomic DNA with restriction enzyme 'E', to Identify true single copy Integration events from LB and RB flanks of the DNA. Based on the above information, the following statements are made:

A. Single copy events from the LB flank Identified using Probe 1 would show two hybridization bands on the Southern blot.

B. Single copy events from the RB flank identified using Probe 2 would show a single hybridization band on the Southern blot.

C. For true single copy events, one hybridization band would be of the same length for each of the two probes used for hybridization.

D. True single copy events would show two bands each for copy number on the left border and right border flanks.

E. There would be no similar hybridization band obtained using Probe 1 and Probe 2.

Which one of the following options represents only correct statements?

QUESTION ID:45

The following table shows a list of evolutionary processes and their associated characteristics
Select the correct option that matches the evolutionary process to its salient characteristic.

QUESTION ID:46

There are different kinds of reactive oxygen species (ROS) generated In plants. The following are the some of the statements related to ROS and its scavenging:
A. H2O2 is relatively more stable and travels relatively long distances.
B. ROS is scavenged only through enzymatic reactions.
c. Ascorbate-glutathione cycle is associated with the scavenging of ROS.
D. Monodehydroascorbate reductase Is not an antioxidant enzyme.
Which one of the following combination of statements is correct?

QUESTION ID:47

The figure below represents the denaturation-renaturation profile of a double stranded DNA in citrate buffer.

The percent of DNA that remains denatured at 300c after cooling from 1000c is:

QUESTION ID:48

Which one of the options correctly represents organisms from the subphyla Chellcerata, Myrlapoda, and Hexapoda, In this specifie sequence?

QUESTION ID:49

Given below are names and recognition sequences of a few restriction enzymes that are used for cloning experiments. The cleavage site of each enzyme is indicated by

EcoRI - G*AATTC

Hincll - GTY*RAC

EcoRV - GAT*ATC

BamHI - G*GATCC

Bglll -A*GATCT

Given below are different vector (Column A) and insert (Column B) fragments generated by digestion using the above enzymes:

Which one of the following options represents the correct combinations of the vector and insert, respectively, which generate compatible ends for ligation?

QUESTION ID:50

The pathway for de novo biosynthesis of purine nucleotides involves the production of inosine monophosphate (IMP) that serves as a precursor for AMP and GMP synthesis. IMP has the base hypoxanthine whose structure is given below:

If hypoxanthine were incorporated into double stranded DNA, which of the following options correctly represents the order of Its pairing preference?

QUESTION ID:51

c. elegans embryo uses both autonomous and conditional modes of specification. The following statements are about speciftcation of ceil lineages:
A. The signals from the P1 blastomere instructs the EMS ceil for its further development.
B. In the absence of the instructive signal, the EMS ceil will divide Into two MS cells.
c. In the absence of the POP-1 signal, the prospective MS ceil can take up the E fate.
D. The MOM-2 protein from the blastomere neighboring the EMS ceil instructs the dividing EMS blastomere to take up MS fate.
Which one of the following options represent both correct statements?

QUESTION ID:52

Following are certain statements regarding gibberellic acid (GA) signal transduction:
A. DELLA proteins negatively regulate GA signalling.
B. Degradation of GA receptor (GID1) is mediated by DELLA proteins.
C. Ubiquitination and subsequent degradation of DELLA proteins are independent of GID1.
D. GA binding to GID1 promotes binding of GID1 to DELLA proteins.
Which one of the following combination of statements is correct?

QUESTION ID:53

Dixon plot is used to study t he enzyme inhibition by p lotting various expressions of velocity (v) and inhibitor concentration [I] on t he X- axis (column A ) and Y-axis (column B ) as given below:
Which one of the following options is the correct combination from columns A and B to draw the Dixon plot?

QUESTION ID:54

In the table below Column I lists terms related to development and Column II contains their descriptions not in a sequential manner:

Select the option with all correct matches between Column I and Column II.

QUESTION ID:55

A student was asked to plot a graph representing enzyme kinetic data for initial velocity, v0, and substrate concentration, [S] using any of the equations given below. The student used an equation for which neither X-axis nor Y-axis had Independent variables. Which one of the following equations might the student have used?

QUESTION ID:56

Fidelity of protein synthesis depends to a large extent on the accuracy of aminoacylation of tRNAs with correct amino acids. However, given that the side chains of many amino acids are not sufficiently ditrerent, aminoacyl-tRNA synthetases (aaRS) are often prone to mis acylate the tRNAs. One such example of mis acylation is of tRNAThr by ThrRS. In this context, following statements are being made about E. coli ThrRS.
A. It mlsacylates tRNAThr equally with Ser and Cys
B. It possesses a distinct editing site that preferentially deacylated the mlsacylated tRNAThr
c. The editing of the misacylated tRNAThr occurs frequently in cis before the release of the misacylated tRNAThr
D. It possesses a distinct editing site that does not discriminate between the misacylated tRNAThr and Thr-tRNAThr
E. The amlnoacylatlon and the editing sites of ThrRS are the same.
Choose the option that represents all correct statements

QUESTION ID:57

The following statements were made to describe a typical collagen structure.
A. Collagen has a triple-helical domain structure which consists of three distinct a-chains.
B. The collagen triple helix is stabilized by isopentyl bonds
C. Each a-chain has a left-handed polyproline II-type helix.
D. Each a-chain is composed of multiple triplet sequences of Gly-Y-Z in which Y is commonly proline and Z is usually hydroxyproline.
Which one of the following options has all correct statements?

QUESTION ID:58

The autoregulation or blood flow In the active tissues Is partly achieved locally by metabolites accumulated In these tissues.
The contributions of different metabolites in this autoregulation are suggested in the following statements:
A. The accumulation of K+ locally in active tissues has vasoconstrictor activity.
B. The Increase In osmolality In active tissues causes vasoconstriction.
c. The accumulation of lactate in active tissues may contribute ta vasoconstriction.
D. The hypoxia-inducible factor-1alpha (HIF-1alpha ) produced due ta local fall in O2 tension in active tissues, initiates the production
of different vasodilatory substances.
E. Histamine released from the damaged cells of active tissues increases capillary permeability.
Choose the option with both correct statements 

QUESTION ID:59

There are many superfamilies of adhesion proteins, which play a central role in cell-cell adhesion in animals. Ig superfamily proteins are one such adhesion proteins. Which one of the following statements about Ig superfamily proteins is INCORRECT?

QUESTION ID:60

The following table shows a list of organisms and associated adaptive characteristics.

Select the correct option that matches the name of the organism with their correct adaptation.

QUESTION ID:61

The following table lists major food crops and the region of domestication:

Which one of the following option represents the correct match between the food crop and its region of domestication?

QUESTION ID:62

Interferons alpha beta and y are cytokines produced and secreted by animal cells after infection by viruses. Which one of the following statements about Interferons Is INCORRECT?

QUESTION ID:63

Following statements are made regarding the properties of two- photon microscopy aver traditional confocal microscopy:
A. By using longer wavelength, two-photon microscopy induces less photobleaching of the tissue preparation.
B. By using shorter wavelength, two-photon microscopy Induces less photobleaching of the tissue preparation.
c. The intensity of fluorescence emitted by the sample will remain the same even if only one of the two exciting photons Impinge an the sample.
D. No fluorescence is detected unless two exciting photons simultaneously impinge an the sample.
Which one of the following combination of statements Is correct?

QUESTION ID:64

Following are a set of statements about various models of succession:
A. In Inhibition model, strong competitive Interaction Is present as no species Is completely superior.
B. In tolerance model, later successional species are neither inhibited nor aided by species of previous stages.
C. In Inhibition model, competitive Interaction Is weak as no species Is completely superior.
D. In facilitation model, later successional species are neither inhibited nor aided by species of previous stages.
Which one of the following options represent correct statements?

QUESTION ID:65

In mice, the gene encoding TbxS Is transcribed In limb fields of the forelimbs, while the genes encoding Isletl, Tbx4 and Pitxl are expressed in presumptive hindlimbs.
Following statements are made about limb development in mouse:
A. Loss of Tbx5 gene results in complete failure of forelimb formation.
B. Hindlimb bud growth and initial patterning appears normal when Tbx4 is knocked out, although leg development is
arrested prematurely.
c. Misexpression of Pitx1. in forelimb ceases development of muscles, bones and tendons.
D. When Islet1 Is Inactivated specifically In the lateral plate mesoderm, the hlndllmbs still develop.
Which one of the following options represents a combination of correct statements?

QUESTION ID:66

In Drosophila, balancer chromosomes are used to keep all the alleles on one chromosome together. A balancer contains multiple inversions; so that when it recombines with the corresponding wild type chromosome, no viable cross over products are formed. Balancers also carry an allele for a dominant phenotype.
A Drosophila male with sepia eye color Is crossed to a female carrying a third chromosome balancer (TM&B). The allele for sepia phenotype (se) is located on chromosome 3 and is recessive to the wild type eye color. The dominant marker for TM&B is a tubby phenotype. Further, an Individual homozygous for TM&B balancer does not survive. F1 progeny with tubby phenotype Is sib-mated.
The F2 progeny Is expected to have:

QUESTION ID:67

The following statements are made about mammalian development:
A. Zygote is a totipotent stem cell.
B. The cells of Inner cell mass are said to be pluripotent.
c. The three regulatory transcription factors, Oct4, Nanog and Sox2 help maintain pluripotency of the inner cell mass.
D. Cdx2 upregulates Oct4 and Nanog.
Which one of the following options represents the correct combination of the statements?

QUESTION ID:68

Excision repair systems replace a short stretch of DNA around the site of damage. The following statements are made about nucleotide excision repair In E. coli:
A. UvrB homodimer creates the nicks on one strand on both side of the lesion.
B. The 50-60 residue-long stretch of DNA between the two nicks Is removed by the action of UvrD.
c. The gap generated is filled in typically by DNA polymerase I.
D. The distortion caused by the lesion Is recognized and bound by uvrA-UvrB complex.
Which one of the following options represents the combination of all correct statements?

QUESTION ID:69

Given below are some statements about pituitary hormones:
A. Oxytocin and vasopressin are synthesized In posterior pituitary
B. Prolactin is synthesized from anterior pituitary
C. a and II MSH are secreted from Intermediate lobe or pituitary In adult humans
D. Growth hormone secretion from anterior pituitary is stimulated by hyperglycemia
E. Prolactin secretion Is markedly Increased by sleep
Choose the INCORRECT combination of statements from below:

QUESTION ID:70

Mouse lgM (whole molecule) was injected into rabbit to generate antiserum. Which one of the following mouse antibody components (the same mouse from which IgM molecules were used for Immunization) has the possibility to be recognized using the rabbit antiserum in Western blotting?

QUESTION ID:71

In eukaryotes, DNA replication must occur with extreme accuracy and only once to prevent the damaging effects of gene amplification. The following statements were made regarding possible mechanisms Involved In achieving tight regulation of DNA replication:
A. High APC/C activity In mitosis and early G1 phase of the cell cycle that triggers the destruction of Cdt1 Inhibitor geminin, thus allowing Cdt1 to be active In early G1 to load helicases.
B. Activation of S-Cdks that regulate the phosphorylation of specific Initiator proteins In the 5-phase.
c. MCM helicase loads at the s-phase of the cell cycle, so that replication begins only at s-phase.
D. Cdc6 and Cdt1 bind to the origin recognition complex (ORC) and help In pre-replicative complex assembly only after mitosis.
Which one of the options has all correct statements?

QUESTION ID:72

The intake of nutrients is under intricate control. A number of statements are made about factors controlling food intake:
A. Cholecystokinin produced from small Intestine stimulates food Intake
B. Leptin produced in adipose tissues stimulates food intake
C. Leptin receptors are located In hypothalamus
D. Ghrelin produced in the stomach inhibits food intake
E. Leptin also stimulates the metabolic rate
F. Ghrelin increases secretion of Neuropeptide Y
Choose the combination of all correct statements from the following options

QUESTION ID:73

The diffraction patterns of two forms of DNA (A and B) and statements related to these patterns are given below.

A. The diffraction pattern corresponding to A-DNA is shown by form 1 with 11.6 base pairs per turn.

B. The diffraction pattern of B-DNA Is shown by form 2 with 11.6 base pairs per turn.

c. The diffraction pattern of A-DNA is shown by form 2 with 11.6 base pairs per turn.

D. The diffraction pattern of B-DNA Is shown by form 1 with 10 base pairs per tum.

Which one of the following options have all correct statements?

QUESTION ID:74

Following statements were made about chromatin remodeling in eukaryotes:
A. Chromatin remodeling completely alters and/or slides the nucleosome, but cannot displace it.
B. Chromatin remodeling Is an energy driven, developmentally regulated active process.
c. Histone acetylation is a reversible process, in which each direction of the reaction is catalyzed by different enzymes.
D. In general, acetylation of core histones reduces their affinity for DNA and destabilizes the chromatin structure, causing transcriptional repression.
E. Phosphorylation or Ser1of histone H2A has been associated with transcription repression.
Which one of the following represents the combination of correct statements?