Menu

Previous Year Questions

TLS Online TPP Program

QUESTION ID:1

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:2

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:3

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:4

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:5

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:6

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:7

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:8

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:9

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:10

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:11

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:12

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:13

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:14

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:15

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:16

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:17

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:18

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:19

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:20

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:21

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:22

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:23

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:24

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:25

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?