PYQ NOV 2020 SIFT 2

CSIR NET BIOLOGY (November - 2020 Sift 2)
Previous Year Question Paper with Solution.

21. Electron transfer from donors such as NADH and FADH₂ to O₂ occurs in

(a) membranes of ER, chloroplast and mitochondria

(b) chloroplast only

(d) organeller membranes which possess ATP synthase

Ans. (c)

Sol. NADH and FADH₂ transfers electrons to oxygen during electron transport chain by which ATP is produced only in mitochondria.

22. Which one of the following enzymes present in erythrocytes helps bypass the first step of ATP formation in glycolysis?

(a) Bisphosphoglycerate mutase

(b) Phosphoglycerate kinase

(d) Phosphofructose mutase

Ans. (a)

Sol. Erythrocytes possess a unique glycolytic bypass for the production of 2, 3-bisphosphoglycerate, the Rapoport-Luebering shunt. This shunt bypasses the phosphoglycerate kinase step and accounts for the synthesis and regulation of 2, 3-bisphosphoglycerate levels that decrease hemoglobin's affinity for oxygen. Bisphosphoglycerate mutase helps to bypass this step in glycolysis.

23. If the pyrollidine ring of proline is reduced to a linear form, the new amino acid will have

(a) constrained than proline

(b) constrained than proline

(d) unaffected and

Ans. (c)

Sol. In proline amino acid, angle is –75° where as angle is 160°. In case we turn pyrollidine ring of proline to linear form its angle will be relaxed as compare to normal proline structure.

24. A plot with which of the following axes is drawn to exhibit enzyme inhibition kinetics applyin Dixon's plot?

(a) V_i vs [I]

(b) 1/V_i vs /[I]

(d) V_i vs 1/[v]

Ans. (c)

Sol. In Dixon's plot, 1/V_i vs [I] axis is drawn to represent enzyme inhibition kinetics.

25. The following table lists names of scientists and advances made by them :

Which one of the following options correctly matches contents of colum A and column B?

(a) P-3, Q-4, R-2, S-1

(b) P-2, Q-3, R-1, S-4

(d) P-1, Q-3, R-2, S-4

Ans. (b)

Sol. P. Linus Pauling : Model of -helix

Q. Emil Fischer : Lock and key model

R. John Kendrew : Myoglobin structure

S. Christian Anfinsen : Sequence structure relationship

26. The Hill equation and its plot describe the following enzyme kinetic behaviours :

P. Saturation kinetics

Q. Cooperatie kinetics

R. Log V_i/(V_max – V_i) versus Log[s]

S. Log (V_max – V_i)/V_i versus Log[s]^–1

Which one of the following combination represents correct descriptions?

(a) P and R

(b) Q and R

(d) P and S

Ans. (b)

Sol. The Hill equation is quantitatively describing cooperative ligand binding. The linear plot of log V_i/(V_max – V_i) versus log[S], the Hill plot, has a slope of n. The slope, referred to as the Hill coefficient, is a measure of the cooperativity of oxygen binding.

27. In regulating the quantity of enzyme, its degradation plays a pivotal role. Following statements are made to represent the degradation of enzymes in the 26S proteasome.

P. The active sites of proteolytic subunits face exterior of the proteasome cylinder.

Q. The active sites of proteolytic subunits face interior of the proteasome cylinder.

R. Degrading enzymes are targeted to exterior of proteasome by covalent attachment of one or more molecules of ubiquitin.

S. Degrading enzymes are targeted to interior of proteasome by covalent attachment of one or more molecules of ubiquitin.

Which one of the following combinations of statements represent correct mode of enzyme degradation?

(a) P and Q

(b) Q and R

(d) P and R

Ans. (c)

Sol. The proteasome degrades proteins by an energy-dependent mechanism. Proteasome do not digest cellular proteins indiscriminately but rather participate in the regulated breakdown of proteins that have been altered to be susceptible to degradation. It catalyzes the ATP dependent degradation of polyubiquitinated proteins.

28. In classical Anfinsen's protein folding experiment the enzymatically active ribonuclease is treated with -mercaptoethanol and 8M urea. Following which, the preparation was

P. dialzed to remove the -mercaptoethanol and 8M urea.

Q. the sample was completely oxidized in 8M urea after dialysis.

R. trace amounts of -mercaptoethanol was added to the dialysed sample.

S. 8M urea was added to the dialyzed sample.

Which one of the following steps will lead to regaining of the full enzymatic activity of ribonuclease?

(a) P followed by R

(b) P followed by Q

(d) P alone

Ans. (a)

Sol. In the presence of urea, a denaturant and -mercaptoethanol, a reducing agent, ribonuclease is denatured and the disulfide bonds are broken. When the protein is allowed to renature by removing the denaturant and the reductant, it regains its native conformation, including four correctly paired disulfide bonds. However, when the reductant is removed while the denaturant is still present, the disulfide bonds are formed again in protein but most of the disulfide bonds are formed between incorrect partners.

29. The following statements were made to describe the role of Gibbs free energy.

P. Reaction can take place spontaneously if is negative.

Q. Reaction can take place spontaneously if is positive.

R. provides no information abuot the rate of a reaction.

S. estimation provides the rate of a reaction.

Which one of the following represents all correct statements?

(a) P and R

(b) Q and R

(d) Q and S

Ans. (a)

Sol. The change in the free energy, , can be used to predict the direction of a reaction at constant temp and pressure. If,

is negative, the reaction proceeds spontaneously with the loss of free energy (exergonic).

is positive, the reaction proceeds only when free energy can be gained (endergonic).

is 0, the system is at equilibrium; both forward and reverse reactions occur at the equal rates.

30. The following statements describe the propensity and role of amino acids in the secondary structure of proteins.

P. Alanine has a high frequency of occurrence in α-helices.

Q. Proline has a high frequency of occurrence in α-helices.

R. The does not affect the helix propensity of serine, threonine and valine.

S. Peptide bonds involving 'N' of proline may display cis-trans isomerism.

Choose the correct combination.

(a) P and S

(b) P and R

(d) R and S

Ans. (a)

Sol. Alanine has a high frequency of occurrence in α-helices and Peptide bonds involving 'N' of proline may display cis-trans isomerism, these statements represents role of amino acid in secondary structure of proteins.

31. Which one of the statements given below is incorrect?

(a) The three common types of membranes lipids are cholesterol, phospholipids and glycolipids.

(b) Phosphoglycerides carry a glycerol backbone, two fatty acid chains and a phosphorylated alcohol.

(d) The common alcohol moieties in phosphoglycerides are glycerol, inositol, choline, ethanolamine and tyrosine.

Ans. (d)

Sol. In phosphoglycerates, alcohol moieties are choline, serine and ethanolamine.

32. The translocation into which one of the organelles listed below does not depend on an amino acid sequence as a signal for import?

(a) Nucleus

(b) Endoplasmic reticulum

(d) Peroxisome

Ans. (c)

Sol. For lysosome import signal is mannose-6-phosphate, which is a non-amino acid based signal patch.

33. The table below lists cell cycle regulatory proteins and their known functions :

(a) P-4, Q-3, R-1, S-2

(b) P-3, Q-2, R-4, S-1

(d) P-1, Q-2, R-3, S-4

Ans. (a)

Sol. P. Cdk-activating kinase (CAK) : Suppresses G1/S-Cdk and S-Cdk activation in G1; helps cells withdraw from cell cycle when they terminally differentiate; phosphorylation by Cdk2 triggers its ubiquitylation by SCF.

Q. Wee1 kinase : Suppresses G1/S-Cdk and S-Cdk activities following DNA damage.

R. p27 (mammals) : Phosporylates inhibitory sites in Cdks: primarily involved in suppressing Cdk1 activity before mitosis.

S. P21 (mammals) : Phosphorylates an activating site in Cdks.

34. The following statements were made regarding the role of protein modifications :

P. Attachement of acetyl groups to the amino termini of proteins makes it more resistant to degradation.

Q. Attachment of hydroxyl groups to proline residues stabilizes fibres of newly synthesized collagen.

R. Addition of sugars (glycosylation) makes protein more hydrophilic enabling protein-protein interactions.

S. Addition of sugars (glycosylation) makes protein more hydrophobic enabling protein foldig.

Which one of the following combinations represents all correct statements?

(a) P, Q and R

(b) P, Q and S

(d) P and S only

Ans. (a)

Sol. Attachement of acetyl groups to the amino termini of proteins makes it more resistant to degradation, Attachment of hydroxyl groups to proline residues stabilizes fibres of newly synthesized collagen and addition of sugars (glycosylation) makes protein more hydrophilic enabling protein-protein interactions.

35. For an exponentially growing culture of bacteria where N₀ is the initial population number of N_t is the population number at time t, the mean growth rate constant (K) is expresed as

(a)

(b)

(c)

(d)

Ans. (a)

Sol. The mean growth rate constant is the number of generations (n) per unit of time (t).

36. The following statements are made with reference to membrane fusion reactions in vesicle transport catalyzed by transmembrane SNARE proteins.

P. The SNARE transmembrane proteins exist as complementary sets, with v-SNARES on vesicle membranes and t-SNARES on target membranes.

Q. A v-SNARE is usually composed of 3 proteins and t-SNARE is a single polypeptide chain.

R. The v-SNARE and t-SNARE proteins of a pair interact via helical domains possessed by the two proteins, resulting in formation of a stable two-helix bundle.

S. Membrane fusion is catalysed by the category by the energy that is freed when the interacting helices warp around each other to pull the membrane faces together, concurrently squeezing out water molecules from the interface.

Which one of the following combinations represents all correct statements?

(a) P and Q

(b) Q and R

(d) P and S

Ans. (d)

Sol. The SNARE transmembrane proteins exist as complementary sets, with v-SNARES on vesicle membranes and t-SNARES on target membranes and Membrane fusion is catalysed by the category by the energy that is freed when the interacting helices warp around each other to pull the membrane faces together, concurrently squeezing out water molecules from the interface.

37. Which one of the following ensures stable binding of RNA polymerase at the promoter site?

(a) DNA photoyase

(b) Sigma factor

(d) Rec A

Ans. (b)

Sol. Sigma factors ensures stable binding of RNA polymerase at the promoter site. It also act as specificity factor.

38. Erythromycin is an inhibitor of protein synthesis. It acts by

(a) binding to 30S subunit of bacterial ribosome, thus inhibiting binding of aminoacyl-tRNAs.

(b) binding to 50S subunit of bacterial ribosome, thus inhibiting translocation.

(d) causes premature chain termination by acting as an analog of aminoacyl-tRNA in both prokaryotes and eukaryotes.

Ans. (b)

Sol. Erythromycin is an inhibitor of protein synthesis. It acts by binding to 50S subunit of bacterial ribosome, thus inhibiting translocation.

39. Genome of an organism was analysed by Cot curve analysis. Highly repeated sequences represented 30% of the total genome fraction. The Cot value of the highly repeated sequence was found to be 0.001 moles nucleotide liter^–1. What would be the acual Cot value (in moles nucleotide liter^–1) of the highly repeated sequence?

(a) 0.003

(b) 0.001

(d) 0.007

Ans. (c)

Sol. Cot value is 0.001 moles nts liter^–1

30% of total Cot value = 0.001 × 30/100 = 0.0003.

40. Which one of the following conditions will switch on Lac operon in E. coli?

(a) + Glucose, + Lactose

(b) + Glucose, – Lactose

(d) – Glucose, + Lactose

Ans. (d)

Sol. Lac operon will switch on in condition when Lactose is present and Glucose is absent.

41. In Trypanosoma, some of the introns generate Y shaped structure in place of a lariat. Such structure is generated during

(a) cis-splicing

(b) trans-splicing

(d) RNA editing

Ans. (b)

Sol. In Trypanosoma, some of the introns generate Y shaped structure in place of a lariat. Such structure is generated during trans-splicing.

42. The following statements are related to transcription in bacteria/eukaryotes.

P. During concurrent promoter sequence recognition and melting, melting commences with base flipping where two bases are flipped out into pockets of the primary sigma factor.

Q. Binding of -amanitin to RNA polymerase II permits entry of nucleotides into RNA pol II active site and synthesis of RNA, but prevents translocation.

R. RNA polymerase I can use upstream promoters with 3 consensus sequences, as well as internal promoters having a bipartite structure.

S. FACT is associated with RNA polymerase during transcriptional elongation and helps displace histone octomers during transcription.

Which of the following combinations of statements represents all correct statements?

(a) P, Q and R

(b) P, Q and S

(d) Q and S only

Ans. (b)

Sol. A histone chaperons, FACT (facilitates chromatin transription), plays an essential role in the process of transcription. It is an evolutionarily conserved, heterodimeric protein. It interacts with the histones H2A-H2B and H3-H4 as well as with DNA. It mediates nucleosome disassembly and reassembly and thus facilitates processes such as transcription and DNA repair-through nucleosomes.

43. Given below is a partial coding sequence of a gene :

5'-A A T G G A C G C A T G T G T C G A T G G-3'

Which one of the following polypeptides cannot be produced by transcription and translation of the above DNA sequence in any of the three possible reading frames?

(a) Asn-Gly-Arg-Met-Cys-Arg-Trp

(b) Asn-Ala-Cys-Phe-Ser-His

(d) Trp-Thr-His-Val-Ser-Met

Ans. (b)

Sol. By following coding sequence of a gene mention in question, three polypeptides which can be produced by three different reading frames are Asn-Gly-Arg-Met-Cys-Arg-Trp, Met-Asp-Ala-Cys-Val-Asp and Trp-Thr-His-Val-Ser-Met.

44. Given below are few statements related to DNA replication :

P. Replication in eukaryotic chromosomes from the origin(s) is initiated multiple times in each cell cycle while it is initiated only once in each cell cycle at the origin in bacterial chromosomes.

Q. Improper reinitation of replication in a eubacterial chromosome is prevented by hemi-methylation status of the bacterial origin.

R. DNA polymerase III is the major replication polymerase responsible for de novo synthesis of both leading and lagging strands of DNA in E. coli.

S. Rolling circle mode of replication produces multiple units of the original molecule.

Which one of the following options represents incorrect statement(s)?

(a) P only

(b) Both Q and R

(d) Q only

Ans. (a)

Sol. Replication in eukaryotic chromosomes from the origin(s) is initiated simultanenously at all origin of replication once in each cell cycle while it is initiated from single Ori once in each cell cycle at the origin in bacterial chromosomes.

45. The mammalian protein HP1 plays a major role in heterochromatinization and silencing. The following mutations are proposed to negatively impact HP1 function.

P. Mutation inactivating the deacetylase that targets H3K14Ac.

Q. Mutations inactivating HP1 bromo-domain.

R. Mutations inactivating HP1 chromo-domain.

S. Mutations inactivating KMT1A methyltransferase whose target site is H3K9.

Which one of the following combinations represents all correct statements?

(a) P, R and S

(b) P, Q and S

(d) R and S only

Ans. (a)

Sol. The mammalian protein HP1 plays a major role in heterochromatinization and silencing. Mutation inactivating the deacetylase that targets H3K14Ac, mutations inactivating HP1 chromo-domain and mutations inactivating KMT1A methyltransferase whose target site is H3K9 impact negatively HP1 function.

46. The following statements are made with reference to the replication of DNA.

P. The eukaryotic counterpart of the bacterial -clamp protien is proilferating cell nuclear antigen (PCNA).

Q. Mutation inactivating one of the subunits of the Mcm 2-7 complex negatively affects the initiation of DNA replication in eukaryote, but has no effect on elongation of the replication fork.

R. All DNA polymerases responsible for replicating the eukaryotic genome catalyze DNA chain extension in a DNA template-dependent manner.

S. The FENI protein plays a role in the synthesis of the lagging strand during DNA replication as well as in base excision repair.

Which one of the following options represents incorrect statement(s)?

(a) Q only

(b) Q and R only

(d) P, Q and R

Ans. (b)

Sol. Mutation inactivating one of the subunits of the Mcm 2-7 complex negatively affects the initiation of DNA replication in eukaryote results in inability of Mcm to perform its helicase activity on replication fork because all subunits of Mcm act cooperatively. DNA polymerase and are DNA dependent DNA polymerases which catalyze DNA chain extension on lagging and leading strand respectively.

47. The statements given below refer to the lambda phage.

1. Clear plaques are formed in Q mutants.

2. No plaques are formed in nut mutants.

3. Clear plaques are formed in cII mutants.

4. Turbid plaques are formed in integrase mutants.

5. Clear plaques are formed in P mutants.

6. No plques are formed in cI mutants.

Which of the following combination of statements is correct?

(a) 1, 2 and 6 only

(b) 3, 4 and 5 only

(d) 4 and 6 only

Ans. (c)

Sol. Plaques are produced on cell lysis in bacteria due to phage infection. In cII mutant, there is direct lytic phage. Hence, clear plaques are found whereas in nut mutants, there is no cell lysis. Hence, no plaques are found.

48. Given below are four sentences with blanks (labelled X, Y, Z and L).

P. RNA Pol I transcribes ...(X)... .

Q. miRNA genes are transcribed by ...(Y)... .

R. The RNA polymerase found only in plants is ...(Z)... .

S. tasiRNAs are synthesized by ...(L)... .

Which one of the following options would present the combination of all terms (in the order X, Y, Z and L) to complete the above sentences correctly?

(a) X : mRNAs, Y : RNA Pol II, Z : RNA Pol IV, L : RNA Pol III.

(b) X : tRNAs, Y : RNA Pol III, Z : RNA Pol V, L : RNA Pol I.

(d) X : 18S rRNA, Y : RNA Pol V, Z : RNA Pol IV, L : RNA Pol I.

Ans. (c)

Sol. P. RNA Pol I transcribes 45S rRNA.

Q. miRNA genes are transcribed by RNA Pol II.

R. The RNA polymerase found only in plants is RNA Pol V.

S. tasiRNAs are synthesized by RNA Pol II.

49. Receptor for which one of the following proteins spans the plasma membrane of target cells but does not contain intrinsic protein kinase activity?

(a) Epidermal growth factor

(b) Insulin

(d) Growth hormone

Ans. (d)

Sol. Epidermal growth factors, insulin and insulin-like growth factor have receptor tyrosine kinase activity. Growth hormone does not show any intrinsic kinase activity.

50. Which one of the following systems forms a chemical mediator that is involved in the mechanism of pain during inflammation?

(a) Activated blood clotting cascade

(b) Plasmin Fibrinolytic system

(d) B-cell activation

Ans. (c)

Sol. Kininogen-Bradykinin system forms a chemical mediator that is involved in the mechanism of pain during inflammation.

51. In the enzyme linked antibody used in ELISA, the interaction between the enzyme and antibody is stabilized by

(a) hydrogen bond

(b) ionic bond

(d) van der Waal's interactions

Ans. (c)

Sol. Antigen-antibody interaction is highly specific and occurs in a similar way as a bimolecular association of an enzyme-substrate. The binding between antigens and immune components involves weak non-covalent interactiosn. The binding forces are relatively weak and reversible and consist mainly of hydrogen bonds, van der Waals forces, ionic interaction and hydrophobic forces.

52. The immunoglobulin heavy-chain that is rearranged first and is displayed on the surface of early stages of B-cell development is associated with

(a) class II associated invariant chain peptide (CLIP).

(b) a surrogate light chain.

(c)

(d) immunoglobulin like cell adhesion molecule.

Ans. (b)

Sol. During B-cell maturation, pro-B-cell is the stage of heavy-chain gene rearrangement, while the next stage is the pre-B-cell stage where heavy-chain is displayed with a surrogate light chain (SL) or invariant light chain. SL itself is made up of two non-covalently associated proteins called V pre-B and lambda 5 (5).

53. Given below are plots that show changing titres of natural killer cells (NK cells), cytotoxic T-lymphocytes specific to the virus (virus-specific CTLs) and interferon during a virus infection. With respect to changing virus titers, select the plots that represent these factors correctly from the options given below.

(a) A : Interferon, B : virus-specific CTLs, C : NK cells.

(b) A : NK cells, B : Interferon, C : virus-specific CTLs.

(d) A : virus-specific CTLs, B : Interferon, C : NK cells.

Ans. (c)

Sol. During a virus infection, titers reach their maximum value of interferons, followed by NK cells and virus-specific CTLs.

54. Dr. Ralph M. Steinman was awarded Nobel Prize for his discovery on :

(a) acquire immunological tolerance.

(b) role of major histocompatibility complex in antigen recognition by T-cells.

(d) role of dendritic cells in adaptive immunity.

Ans. (d)

Sol. Dr. Ralph M. Steinman was awarded Nobel Prize for his discovery on role of dendritic cells in adaptive immunity.

55. cGMP is produced from GTP by the enzyme guanylate cyclase which exists in soluble and membrane bound forms. Following statements are made related to signaling molecules that are associated with cGMP signaling cascade.

P. Atrial natriuretic factor causes natriuresis and diuresis by interacting with membrane bound form of guanylate cyclase.

Q. Nitroglycerin causes smooth muscle relaxation and vasodilation by interacting with soluble form of guanylate cyclase.

R. Nitroprusside causes smooth muscle relaxation and vasodilation by interacting with membrane-bound form of guanylate cyclase.

S. Atrial natriuretic factor causes natriuresis and diuresis by interacting with soluble form of guanylate cyclase.

Which one of the following combinations is correct?

(a) P and Q

(b) Q and R

(d) P and S

Ans. (a)

Sol. Atrial natriuretic factor causes natriuresis and diuresis by interacting with membrane bound form of guanylate cyclase and Nitroglycerin causes smooth muscle relaxation and vasodilation by interacting with soluble form of guanylate cyclase.

56. Three starins of pathogenic bacteria were found to express proteins mimicking human proteins associated with complement pathway. Bacterium 'X' expressed on its surface proteins mimicking Decay Accelerating Factor (DAF) and Complement Receptor 1 (CR1). Bacterium 'Y' secreted a protein that mimicked protein S of humans and bacterium 'Z' secreted protein that mimicked Factor I activity. Given below are statements on the possible effect of complement activation on these pathogenic bacteria. Select the incorrect statement.

(a) Bacterium X will prevent formation of C3 convertase on its surface by alternate and classical pathways.

(b) Bacterium Y will prevent formation of C3 convertase on its surface by lectin pathway.

(c) Bacterium Z will be susceptible to complement attack by Membrane Attack Complex (MAC) despite secreting Factor-I-like protein to cleave C3b and C4b.

(d) Bacterium Y will prevent formation of Membrane Attack Complex (MAC) on its surface.

Ans. (b)

Sol. Three starins of pathogenic bacteria were found to express proteins mimicking human proteins associated with complement pathway. Bacterium 'X' expressed on its surface proteins mimicking Decay Accelerating Factor (DAF) and Complement Receptor 1 (CR1). Bacterium 'Y' secreted a protein that mimicked protein S of humans and bacterium 'Z' secreted protein that mimicked Factor I activity.Bacterium X will prevent formation of C3 convertase on its surface by alternate and classical pathways, bacterium Z will be susceptible to complement attack by Membrane Attack Complex (MAC) despite secreting Factor-I-like protein to cleave C3b and C4b and bacterium Y will prevent formation of Membrane Attack Complex (MAC) on its surface.

57. Following are the statements which explain why patients with -linked hyper IgM syndrome express normal gene for other antibody subtypes but fail to produce IgG, IgA or IgE :

P. CD40 expressed on B-cells is defective.

Q. CD40L mediates binding of B-cells to T-cells and sends co-stimulatory signals to the B-cells for class switching.

R. Without CD40 on macrophage, class switching does not occur.

S. CD40L mediates binding of B-cells to macrophages and sends costimulatory signals to the B-cells for class switching.

Select the option with correct combination.

(a) P, R and S

(b) P, Q and R

(d) P and S

Ans. (c)

Sol. Patients with -linked hyper IgM syndrome express normal gene for other antibody subtypes but fail to produce IgG, IgA or IgE. This is because CD40 expressed on B-cells is defective and CD40L mediates binding of B-cells to T-cells and sends co-stimulatory signals to the B-cells for class switching.

58. Suresh was bitten by a poisonous snake and was immediately treated with anti-venom human immunoglobulin and was saved. A year later he was bitten by the same type of snake second time. Predict his response to the venom form second bit from the following:

(a) He will be fully protected from the effects of the poison second time because he developed adaptive immunity after first snake bite.

(b) He will be equally sensitive as first encounter because ther would be no recall of the first encounter.

(c) There are residual cells or anti-venom antibodies that were involved in the original/first encounter, hence he will be protected.

(d) There will be memory cells made after the first encounter hence he will be more sensitive.

Ans. (b)

Sol. Treatment using antivenom antibodies is an example of passive immunity. The person will develop no memory for secondary response to the target antigen. Hence, Suresh will be equally sensitive in the second bite.

59. PR proteins play important role during plant-pathogen interactions. Column X represents some of the PR family proteins and Column Y represents their main properties.

The correct match of column X with the property in column Y is

(a) P-4, Q-3, R-2, S-1

(b) P-1, Q-2, R-3, S-4

(d) P-3, Q-4, R-2, S-1

Ans. (c)

Sol. P. PR-2 : -1, 3-glucanase

Q. PR-5 : Thaumatin-like

R. PR-12 : Defensin

S. PR-14 : Lipid transfer protein

60. Pathogens continuously evolve strategies to evade host immune responses. For each of the following evasion strategies (listed in Column X) match the pathogen (listed in Column Y) which adopts it :

Choose the correct match.

(a) P-1, Q-3, R-2, S-4, T-1

(b) P-1, Q-4, R-3, S-2, T-1

(d) P-2, Q-4, R-3, S-2, T-1

Ans. (b)

Sol. P. Changing the antigen expressed on their surface : Influenza virus

Q. Increasing phagocytic activity on macrophage : No bacteria

R. Developing resistance to complement mediated lysis : Gram +ve bacteria

S. Secreting proteases to inactivate antibodies : Neisseria

T. Allowing point mutations in surface epitopes resulting in antigenic drift : Influenza virus

61. For a given immunological application (column X), select the type of antibody (column Y) that should be used :

Choose the option with correct matches between terms of columns X and Y.

(a) P-2, Q-1, R-3, S-1

(b) P-3, Q-3, R-1, S-1

(d) P-1, Q-3, R-1, S-2

Ans. (b)

Sol. P. Bacterial agglutination : Either monoclonal or polyclonal

Q. Western blotting : Either monoclonal or polyclonal

R. Detection of a cytokine using a should phase of ELISA : Only monoclonal

S. Diagnostic tissue typing : Only monoclonal

62. An antigen was injected into a mouse. Macrophages and antigen primed T_H cells were isolated from this mouse to perform the following in vitro experiments :

P. Macrophages were treated with the antigen for an huor and then incubated with T_H cells.

Q. Macrophages were treated with paraformaldehyde first and then treated with the antigen for an hour. These macrophages were then incubated with T_H cells.

R. Macrophages were treated with paraformaldehyde first then treated with the digested (proteolytic cleaved) andtigen for an hour. These macrophages were then incubated with T_H cells.

S. Macrophages were treated with the antigen for an hour and then treated with paraformaldehyde. These macrophages were then incubated with T_H cells.

Which of the above experiments would lead to T_H cells proliferation?

(a) P and S only

(b) Q only

(d) R and S only

Ans. (c)

Sol. Only in the case of P, R and S, macrophages will present the antigen and TH cells will proliferate. In the case of Q, macrophages are treated with paraformaldehyde that inhibits their capacity of antigen processing.

63. Which one of the following statements regarding double fertilization in plants is correct?

(a) The same sperm cell fuses with both egg cell and central cell.

(b) Two sperm cells fuse with the egg cell.

(d) Two sperm cells fuse with one central cell.

Ans. (c)

Sol. In double fertilization in plants, one sperm cell fuses with the egg cell and the second with the central cell.

64. Human polysyndactylyl (joining of extra digits) syndrome results from a homozygous mutation at

(a) antennapedia complex locus

(b) one of the genes of Hox D

(d) -catenin locus

Ans. (b)

Sol. Human polysyndactylyl (joining of extra digits) syndrome results from a homozygous mutation at one of the genes of Hox D.

65. Suppression of VPE (Vacuolar Processing Enzymes) gene expression in Nicotiana benthamiana plants will not

(a) abolish hypersensitive response

(b) enhance TMV (Tobacco Mosaic Virus) infection

(d) reduce DNA fragmentation

Ans. (b)

Sol. Suppression of VPE (Vacuolar Processing Enzymes) gene expression in Nicotiana benthamiana plants will not enhance TMV (Tobacco Mosaic Virus) infection. But can abolish hypersensitive response, reduce caspase like activity and reduce DNA fragmentation.

66. Sonic hedgehog (Shh) specifies the anterior-posterior axis during limb development. Which one of the following statements regarding it is correct?

(a) Shh secreting cells undergo apoptosis after performing its function.

(b) Descendants of Shh secreting cells become the bone and muscle ofthe anterior limb.

(c) When the genes for Shh and Gli3 are conditionally knocked out in the mouse limb, the resulting limbs do not form any digit.

(d) Specification of the digit is primarily dependent on the amount of time the Shh gene is expressed and to a small extent on the concentration of the Shh protein that other cells receive.

Ans. (d)

Sol. Specification of the digit is primarily dependent on the amount of time the Shh gene is expressed and to a small extent, on the concentration of the Shh protein that other cells receive. It is the only correct statement about Shh in the given options.

67. Which of the following statements regarding amphibian development is correct?

(a) The Nieuwkoop centre is formed on the dorsal side of the embryo due to accumulaton of -catenin which helps activate the siamois and twin genes.

(b) The ectodermal cells form neural tissues in the presence of BMP molecules.

(d) There is a gradient of Nodal-related protein across the endoderm with low concentration of the dorsal side of the embryo.

Ans. (a)

Sol. The Nieuwkoop center is formed on the dorsal side of the embryo due to the accumulation of -catenin, which helps activate the siamois and twin genes. This is the only correct statement.

68. Dreisch performed the "pressure plate experiment" to alter the distribution of nuclei in 8-cell sea urchin embryo. He obtained normal larvae from these embryos. Following possible conclusions could be drawn :

P. Prospective potency of the blastomeres is less than actual prospective fate.

Q. Sea urchin embryo as a "harmonious equipotential system" implying that cell interaction is critical for normal development.

R. Prospective potency of the blastomere is greater than the actual prospective fate.

S. Prospective potency of the blastomere is equal to the prospective fate.

Which one of the following combinations of statements represents the correct interference from the experiment?

(a) P and Q

(b) Q and R

(d) S only

Ans. (b)

Sol. Dreisch performed the "pressure plate experiment" to alter the distribution of nuclei in 8-cell sea urchin embryo. Sea urchin embryo as a "harmonious equipotential system" implying that cell interaction is critical for normal development and prospective potency of the blastomere is greater than the actual prospective fate.

69. Several marine organisms release their gametes into the environment, where sperm attraction and subsequent events leads to successful fertilization. With reference to sea urchins, which of the following statement is not true?

(a) Addition of resact into a drop of seawater containing sperms specifically attracts sperms of A. punctulata.

(b) IP₃ is formed initially at he site of sperm entry and releases sequestered Ca²⁺.

(d) Inhibitors that specifically block can be circumvented by microinjecting IP₃ into the egg.

Ans. (c)

Sol. Several marine organisms release their gametes into the environment, where sperm attraction and subsequent events leads to successful fertilization. Addition of resact into a drop of seawater containing sperms specifically attracts sperms of A. punctulata, IP₃ is formed initially at the site of sperm entry and releases sequestered Ca²⁺ and Inhibitors that specifically block can be circumvented by microinjecting IP₃ into the egg.

70. In C. elegans, activation of the CED-3 and CED-4 proteins are essential for the apoptosis pathway. In addition, gain of function mutations in the ced-9 gene cause its protein to be made in cells that would normally die, resulting in survival of those cells. Given these facts, which of the following diagrams correctly represents a cell death pathway?

(a)

(b)

(c)

(d)

Ans. (d)

Sol. Apoptotic genes are evolutionary conserved from invertebrates to higher vertebrates.

71. The major structural characteristic of avian gastrulation is the primitve streak, which becomes the blastopore lips of amniotic embryos. Migration through the primitive streak is controlled by Fgf8. What would happen if the Fgf8 protein, which repels migrating cells away from the streak, is over expressed in the primitve streak?

(a) The yolk sac will be deformed.

(b) Wnt signalling will be activated and orientation of the primitive streak will change.

(d) Cells generate mesodermal portion of the embryo.

Ans. (b)

Sol. The major structural characteristic of avian gastrulation is the primitve streak, which becomes the blastopore lips of amniotic embryos. Migration through the primitive streak is controlled by Fgf8. If the Fgf8 protein, which repels migrating cells away from the streak, is over expressed in the primitve streak, Wnt signalling will be activated and orientation of the primitive streak will change.

72. The continued expression of engrailed and wingless is maintained by interactions between the Engrailed and Wingless expressing cells. The following statements are given towards the initiation of the cascade of events that occur for this interaction :

1. The engrailed gene is an expressed in cells where neither even skipped nor fushi tarazu gene is active.

2. The wingless gene is expressed in those cells that contain high concentration of either Even skipped of Fushi tarazu.

3. Wingless is a secreted protein, diffuses to the surrounding, binds with the Frizzled and Lrp 6 receptor proteins and activates engrailed gene via Armadillo.

4. Hedgehog protein activates the transcription of engrailed and also activates its own transcription.

5. Hedgehog protein diffuses from cells and binds to Patched receptor on neighbouring cells and enables transcription of wingless gene.

Which combination of above statements correctly represent the maintenance of engrailed and wingless expression?

(a) 1 and 2

(b) 2 and 4

(d) 3 and 5

Ans. (d)

Sol. The continued expression of engrailed and wingless is maintained by interactions between the Engrailed and Wingless expressing cells. Wingless is a secreted protein, diffuses to the surrounding, binds with the Frizzled and Lrp 6 receptor proteins and activates engrailed gene via Armadillo and Hedgehog protein diffuses from cells and binds to Patched receptor on neighbouring cells and enables transcription of wingless gene.

73. In which of the following subcellular organelles is serine synthesized during the oxidative photosynthetic carbon (C₂) pathway?

(a) Chloroplast

(b) Mitochondria

(d) Rough endoplasmic reticulum

Ans. (b)

Sol. In mitochondria, serine synthesized during the oxidative photosynthetic carbon (C₂) pathway

74. Arteminsinin and Dhurrin belong to which two respective groups of the plant neutral compounds?

(a) Alkaloids and Terpenes

(b) Flavonoids and Alkaloids

(d) Terpenes and Cynogenic glycosides

Ans. (d)

Sol. Arteminsinin and Dhurrin belong to Terpenes and Cynogenic glycosides of the plant neutral compounds.

75. Spermidine represents which of the following group of compounds :

(a) jasmonic acid

(b) polyamine

(d) strigolactone

Ans. (b)

Sol. Spermidine is a polyamine compound found in ribsomes and living tissues. It is originally isolated from semen.

76. Programmed cell death (PCD) plays an important role in development of barley aleurone. The following statements are made with respect to involvement of various phytohormones and signaling molecules.

P. Gibberellic acid promotes PCD.

Q. Abscisic acid postpones PCD.

R. Cyclic GMP signaling postpones PCD.

S. Nitric oxide scavenger delays PCD.

Which one of the following combinations of statements is correct?

(a) P and R

(b) Q and S

(d) R and S

Ans. (c)

Sol. Programmed cell death (PCD) is a controlled mechanism that eliminates specific cells under developmental or environmental stimuli. In plants, PCD activation ensures the correct occurrence of growth and developmental processes, among which embryogenesis adn differentiation of tracheary elements. PCD is also part of the defense responses activated by plants against environmental stresses, both abiotic and biotic. The aleurone layer of cereals is a secretory tissue whose activity is regulated by abscisic acid (ABA) and gibberellins (GAs). Whereas GA triggers enzyme synthesis and secretion and initiates a program that culminates in cell death, ABA prevents enzyme production and cell death.

77. Following are certain statements regarding nitrogen uptake and assimilation by plants :

P. Plant roots can take up nitrogen in the form of or .

Q. taken up by plants can be directly assimilated into amino acids.

R. Amino acids are synthesized exclusively in plastids and chloroplast of roots and leaves, respectively.

S. can be stored in vacuole of both, roots and leaves.

Which one of the following combinations is correct?

(a) P, Q and R

(b) Q, R and S

(d) P, R and S

Ans. (c)

Sol. During nitrogen uptake and assimilation, Plant roots can take up nitrogen in the form of or , taken up by plants can be directly assimilated into amino acids and can be stored in vacuole of both, roots and leaves.

78. The NPR1 (non-expressor of pathogenesis-related genes 1) and two SA receptors (NPR3 and NPR4) are known to play important role in SA mediated plant defense. The following statements were made regarding their role in infected and non-infected tissuse of the plants :

P. In the infected tissue, SA binds to NPR3 and induces degradationof NPR1 to promote cell death.

Q. In the infected tissue, SA binds to NPR4 and blocks the degradation of NPR1 to promote cell death.

R. In the non-infected tissue, SA binds to NPR4 and blocks the degradation of NPR1 to favour cell survival.

S. In the non-infected tissue, SA binds to NPR3 and promotes degradation of NPR1 to favour cell survival.

Which one of the following combination of statements is correct?

(a) P only

(b) Q only

(d) Q and S

Ans. (c)

Sol. The NPR1 (non-expressor of pathogenesis-related genes 1) and two SA receptors (NPR3 and NPR4) are known to play important role in SA mediated plant defense. In the infected tissue, SA binds to NPR3 and induces degradationof NPR1 to promote cell death and in the non-infected tissue, SA binds to NPR4 and blocks the degradation of NPR1 to favour cell survival.

79. Dark grown Arabidopsis seedlings when exposed to ethylene gas shows typical triple response. Followings are certain statements regarding the triple response :

P. A dominant ethylene receptor will not show triple response in the presence of ethylene.

Q. Tightening of apical hook is one of the features of triple response.

R. Loss of function of multiple receptors will show triple response even in the absence of ethylene.

S. Increase in hypocotyl length is a feature of triple response.

Which one of the following combinations is correct?

(a) P, Q and R

(b) P, R and S

(d) P, Q and S

Ans. (a)

Sol. Ethylene is associated with fruit ripening and the triple respone. The triple response on dark-grown pea seedlings include reduced stem elongation, increased stem thickening and horizontal growth habit.

80. A researcher has treated pea leaves with p-chloromercuribenzene sulfonic acid (PCMBS), which inactivates plasma membrane transporters. It was observed that phloem loading of sucrose is inhibited. Which one of the following interpretations is correct?

(a) Symplastic loading is eliminated.

(b) Apoplastic loading is eliminated.

(d) Both symplastic and apoplastic loadings are eliminated.

Ans. (b)

Sol. A researcher has treated pea leaves with p-chloromercuribenzene sulfonic acid (PCMBS), which inactivates plasma membrane transporters. It was observed that phloem loading of sucrose is inhibited. It occurs when apoplastic loading is eliminated.

81. A researcher developed a mutant of Arabidopsis plant where the function of SLEEPY 1 (SLY1) containing SCF complex has been disrupted. Which one of the following statements is incorrect in the developed mutant in relation toe gibberellic acid (GA) signal transduction?

(a) GA will bind to GA-insensitive dwarf 1 (GID1) protein.

(b) A complex of GA-GID1 and DELLA protein will be formed.

(d) The DELLA protein will not be degraded.

Ans. (c)

Sol. A researcher developed a mutant of Arabidopsis plant where the function of SLEEPY 1 (SLY1) containing SCF complex has been disrupted. In developed mutant, GA will bind to GA-insensitive dwarf 1 (GID1) protein, a complex of GA-GID1 and DELLA protein will be formed and the DELLA protein will not be degraded.

82. Calvin-Benson cycle is divided into three phases, namely carboxylation, reduction and regeneration. The following statements are related to the three phases of Calvin-Benson cycle :

P. The product of light reaction, ATP and NADPH is utilized in the carboxylation phase.

Q. Six molecules of 3-phosphoglycerate is converted into six molecules of glyceraldehyde 3-phosphate in the reduction phase.

R. The action of aldolase enzyme for the production of fructose 1, 6-bisphosphate takes place in reduction phase.

S. Formation of seven carbon compound, sedoheptulose-7-phosphate takes place in the regeneration phase.

Which one of the following combinations is correct?

(a) P and R

(b) Q and S

(d) R and S

Ans. (b)

Sol. Six molecules of 3-phosphoglycerate is converted into six molecules of glyceraldehyde 3-phosphate in the reduction phase and formation of seven carbon compound, sedoheptulose-7-phosphate takes place in the regeneration phase.

83. In both males and females, the gonads secrete a polypeptide hormone, called inhibin B, which inhibits

(a) luteinizing hormones

(b) follicle-stimulating hormone

(d) thyroid stimulating hormone

Ans. (b)

Sol. In both males and females, the gonads secrete a polypeptide hormone, called inhibin B, which inhibits follicle-stimulating hormone.

84. Which one of the following is not released by sympathetic preganglionic neurons?

(a) Neurotensin

(b) Enkephalin

(d) Substance P

Ans. (c)

Sol. Serotonin is not released by sympathetic preganglionic neurons. But Neurotensin, Enkaphalin and Substance P are released by sympathetic preganglionic neurons.

85. Which one of the following routes is responsible for maximum amount of body heat loss in humans at an ambient temperature of 21°C?

(a) Radiation and conduction

(b) Respiration

(d) Vaporization of sweat

Ans. (a)

Sol. Radiation and conduction is responsible for maximum amount of body heat loss in humans at an ambient temperature of 21°C.

86. In mammals, the primary circadian clock is located in which of the following parts of the brain?

(a) Occipital lobe of cerebrum

(b) Amygdala

(d) Frontal lobe of cerebrum

Ans. (c)

Sol. In mammals, the primary circadian clock is located in Suprachiasmatic nucleus of hypothalamus in the brain.

87. In high altitude, a number of compensatory mechiansms operate over a period of time to increase altitude tolerance in humans while is caleld acclimatization. The following statements propose these compensatory changes :

1. The initial increase of ventilation is relatively small in high altitude but he ventilation steadily increases over next few days.

2. Red blood cell 2, 3-DPG is increased.

3. The blood pH becomes more alkaline.

4. The oxygen dissociation curve is shifted to the left.

5. The pH of cerebrospinal fluid is further increased.

Choose the option with both incorrect statements :

(a) 1 and 2

(b) 2 and 3

(d) 4 and 5

Ans. (d)

Sol. Effect of BPG : BPG is a highly charged anion. In deoxygenated state, hemoglobin binds one molecule of BPG. It stabilizes deoxygenated hemoglobin by forming additional salt bridges and therefore reduces the O₂ affinity of hemoglobin (by a factor of 26). An increase in the concentration of BPG shifts the graph to the right. Ascent to high altitude triggers a substantial rise in BPG concentration in red cells. The high altitude induced increase in BPG causes a decrease in hemoglobin's oxygen affinity.

88. A researcher intends to stimulate neurons via glutamate receptors in medial septum of an experimental animal. The following apparatus/instruments are available in the laboratory:

1. Stereotaxic apparatus

2. Slow perfusion pump

3. Microcannula

4. Radiofrequency lesion maker

5. Electrical stimulator

6. Nichrome coated bipolar steel electrode

Which one of the following options contains all the correct items required for the experiment?

(a) 1 and 2 only

(b) 1, 2 and 3

(d) 4, 5 and 6

Ans. (b)

Sol. Stimulation of neurons by glutamate receptors in medial septum is done experimentally with the help of stereotaxic apparatus to keep head in fixed position, slow perfusion pump and microcannula for introducing glutamate receptor stimulators.

89. Kallmann syndrome generally exhibits gonadal dysfunctions in males. Following statements are made relating to such males.

P. They mostly suffer from hypergonadism.

Q. They mostly suffer from hypogonadism.

R. They have higher level of circulating gonadotropins.

S. They have lowe rlevel of circulating gonatoropins.

Which one of the following combinations of statements is correct?

(a) P and Q

(b) Q and R

(d) P and R

Ans. (c)

Sol. Kallmann syndrome is a rare genetic disorder in humans, defined by a delay/absence of signs of puberty along with an absent sense of smell. It occurs due to a deficiency of GnRH. It occurs in both sexes and suffers from hypogonadism.

90. Loss of a large quantity of blood in an individual due to haemorrhage provokes many physiological changes which are compensatory and decompensatory in nature. The following statements describe few compensatory in nature. The following statements describe few compensatory or decompensatory mechanisms operating in this condition.

1. The peripheral chemoreceptors are stimulated when arterial blood pressure is reduced below 60 mm Hg due to blood loss.

2. The cardiovascular centres in the brain stem become depressed in severe hypotension due to blood loss.

3. The mononuclear phagocytic system becomes depressed during the course of haemorrhagic hypotension.

4. Renin is secreted from juxtaglomerular apparatus in haemorrhagic hypotension.

5. Considerably quantity of interstitial fluid may be drawn into circulation due to lowe hydrostatic pressure in capillaries resulting from blood loss.

Choose the option descending only the decompensatory mechanisms :

(a) 1 and 2

(b) 2 and 3

(d) 4 and 5

Ans. (b)

Sol. Loss of a large quantity of blood in an individual due to haemorrhage provokes many physiological changes which are compensatory and decompensatory in nature. The cardiovascular centres in the brain stem become depressed in severe hypotension due to blood loss and the mononuclear phagocytic system becomes depressed during the course of haemorrhagic hypotension.

91. The electrical response of the afferent nerve terminal in a Pacinian corpuscle (PC), after application of different grades of pressure, are proposed in the following statements :

1. A non-propagated depolarizing potential or receptor potential is elicited when small magnitude of pressure is applied to PC.

2. The magnitude of receptor potential is increased as the pressure to PC is increased.

3. An action potential is generated when receptor potential attains a critical value.

4. The receptor potential shows all or more response.

5. The receptor potential is not a graded potentials.

Choose the option with both incorrect statements :

(a) 1 and 2

(b) 2 and 3

(d) 4 and 5

Ans. (d)

Sol. The electrical response of the afferent nerve terminal in a Pacinian corpuscle (PC), after application of different grades of pressure, A non-propagated depolarizing potential or receptor potential is elicited when small magnitude of pressure is applied to PC, the magnitude of receptor potential is increased as the pressure to PC is increased and an action potential is generated when receptor potential attains a critical value.

92. The discharge patterns in a single afferent nerve fibre from carotid sinus at various levels of mean arterial pressure (MAP) are plotted against changes in aortic pressure with time in the following figure :

The following figure statements were proposed from the figure :

1. Baroreceptors are more sensitive to phasic change of aortic pressure at normal MAP.

2. The baroreceptor firing rate is reduced at lower MAP than in normal MAP.

3. The phasic change in baroreceptor fibre is less prominent at lower MAP.

4. A burst of action potentials appear in a single baroreceptor fibre during diastole at normal MAP.

5. The discharge of baroreceptors even extends to systole at higher MAP.

Choose the option with both correct statements :

(a) 1 and 2

(b) 2 and 3

(d) 4 and 5

Ans. (a)

Sol. By observing graph given in question, baroreceptors are more sensitive to phasic change of aortic pressure at normal MAP and the baroreceptor firing rate is reduced at lower MAP than in normal MAP.

93. Which one of the following statements is true with regard to drug metabolism?

(a) The therapeutic window is simply the range of plasma drug concentrations in which the drug has therapeutic benefits without causing extra safety risks due to drug toxicity.

(b) Each individual drug molecule is metabolized by a specific drug metabolizing enzyme that is dedicated to metabolism of that drug.

(d) A poor metabolizer is a person who cannot metabolize a drug properly and faces risk of underdoes.

Ans. (a)

Sol. The therapeutic window is simply the range of plasma drug concentrations in which the drug has therapeutic benefits without causing extra safety risks due to drug toxicity.

94. A gene was located on 10p11. This means the gene was located on the

(a) short arm of chromosome 10 at G-sub band 1 of band 1.

(b) short arm of chromosome 10 at G-band 11.

(d) long arm of chromosome 10 at G-sub band 1 of band 1.

Ans. (a)

Sol. If we write the location of a gene as 13q14. It means that gene is located in band 4 in region 1 of the long arm of chromosome 13. Sub-band is depicted by giving a decimal point after the band position and is followed by the number assigned to each sub-band. For example, 13q14.2 represents sub-band 2 of 13q14.

95. The trait shown in the below pedigree is

(a) X-linked recessive trait

(b) autosomal recessive trait

(d) X-linked trait

Ans. (b)

Sol. The trait cannot be of dominant type as progenies are getting diseased even while both the parents are normal (skipping a generation). It cannot by Y-linked recessive or X-linked recessive as progenies are shown diseased even while father is normal. Only autosomal characters are shown by the given pedigree.

96. A plant that produces disc-shaped fruit is crossed with another plant taht produces long fruit. All the F1 plants gave disc-shaped fruits. When the F1 were intercrossed, F2 progeny were produced in the following ratio : 9/16 plants with disc-shaped fruits; 6/16 plants with spherical fruits and 1/16 plants having long fruits. Which one of the following options gives correct genotype of spherical fruits obtained in F2?

(a) A_bb only

(b) aaB_ only

(d) A_B_ and aabb

Ans. (c)

Sol. plants with spherical fruit would have genotype AAbb, Aabb, aaBb and aaBB.

97. The maximum frequency of recombination that can occur between two loci is

(a) 25%

(b) 50%

(d) 100%

Ans. (b)

Sol. Maximum 50% frequency of recombination can occur between two loci.

98. A panel of six hybrid cell lines, each containing a different subset of human chromosomes, was examined for the presence of the gene product as shown below :

The gene which codes for the given gene product is located on which chromosome?

(a) Chromosome 3, 4 or 5

(b) Chromosome 3

(d) Chromosome 4

Ans. (d)

Sol. By observing, table given in question the gene must lie on chromosome 4.

99. The figure below represents a profile of DNA markers in two parents (P1 and P2), progeny (F1) from a cross between P1 and P2 and that of gametes produced from F1. Eight different patterns (DH1 to DH8) were observed in case of gametes. The numbers below, DH1 to DH8 indicate the number of individuals observed in each case :

Based on the above observations, the following statements were made :

P. Markers 'b' and 'f' are likely to be allelic in nature.

Q. Markers 'c' and 'd' are linked in trans a map distance of 24 cM.

R. Marker 'b' assorts independently from marker 'c'.

Which one of the following have a combination of all correct statements?

(a) P, Q and R

(b) P and Q

(d) R only

Ans. (c)

Sol. As per the information provide in question and repersentation of markers in gel, Markers 'b' and 'f' are likely to be allelic in nature because presence of one marker excludes other marker which is characterstic of alleles of same gene.

100. Curled wing (cu), ebony body colour (e) and sepia eye (se) are these recessive mutations that occur in fruit flies. The loci for these statements have been mapped and they are separated by the following hypothetical map distances :

The interference between these genes is 0.4.

A mutant cu e se fly was crossed with a homozygous wild-type fly. The resulting F1 females were test crossed that produced 1800 progeny. What number of flies in each phenotype class is likely to be obtained in the progeny of the test cross?

(a) Non-recombinants will be 1250; single crossover between cu and e 334; single corssover between e and se 190; double crossover 26.

(b) Non-recombinants 1181; single crossover between cu and e 360; single corssover between e and se 216; double crossover 43.

(d) Non-recombinants 1233; single crossover between 524; double crossover 43.

Ans. (a)

Sol. The correct option is (a).

101. E.coli cells were simultaneously infected with two strains of phage . One strain of had a mutant host range, is temperature sensitive and known to produce clear plaques (genotype h st c); another strain of carried the wild-type alleles (genotype h⁺ st⁺ c⁺). Progeny phages were collected from the lysed cells and were plated on bacteria. The following numbers of different progeny were obtained :

What will be the order of the three genes and the map distance between them?

(a)

(b)

(c)

(d)

Ans. (c)

Sol. The correct option is (c).

102. In some sheep, horns are produced by an autosomal allele, 'H', that is dominant in males and recessive in femalse. H⁺H⁺ individuals are hornless. A horned female is crossed with a hornless male. One of the resulting F1 females is crossed with a hornless male. What proportion of the male and female progeny of F1 will have horns?

(a) 50% of male and 50% of female progeny will be horned.

(b) 50% of male progeny but none of the female progeny will be horned.

(d) 100% of male progeny and 50% of female progeny will be horned.

Ans. (b)

Sol. Genotype Male phenotype Female phenotype

HH horned horned

Hh horned hornless

hh hornless hornless

HH (female, horned) × hh (male, hornless) Hh (horned males and hornless female)

Hh (female, hornless) × hh (hornless, male) male : 1/2 Hh (horned) and 1/2 hh

(hornless)

female : Hh (hornless) and hh (hornless)

103. A species fo plant (species 1) is diploid (2n = 6) with chromosomes AABBCC and a related species (species 2) is also diploid (2n = 4) with chromosome PPQQ. The following statements were given by students regarding the chromosome numbers involving these plant speices :

1. Autotriploid of species 1 will have 12 chromosomes.

2. Alloetetraploid involving species 1 and 2 will have 16 chromosomes.

3. A monsomy in species 1 will generated 4 chromosomes.

4. A double trisomy in species 1 will generate 8 chromosome.

5. A nullisomy in species 2 will generate 2 chromosomes.

The combination of statements will all correct answer is

(a) 1, 2 and 3

(b) 2, 3 and 4

(d) 4, 5 and 1

Ans. (c)

Sol. A species fo plant (species 1) is diploid (2n = 6) with chromosomes AABBCC and a related species (species 2) is also diploid (2n = 4) with chromosome PPQQ. A monsomy in species 1 will generated 4 chromosomes, a double trisomy in species 1 will generate 8 chromosome and a nullisomy in species 2 will generate 2 chromosomes.

104. Body weight of rabbits is determined by pairs of alleles at two loci, 'a' and 'b', that are additive and equal in their effects. Rabbits with genotype a^– a^– b^– b^– have average 1 kg body weight, whereas individuals with genotype a⁺ a⁺ b⁺ b⁺ have animals that average 3.4 kg in weight. A male rabbit with a^– a^– b^– b^– is crossed with a female of genotype a⁺ a⁺ b⁺ b⁺. What will be predicted average weight of F1 progeny of this cross?

(a) 2.2 kg

(b) 1.6 kg

(d) 2.8 kg

Ans. (a)

Sol. Rabbits with genotype a^– a^– b^– b^– have average 1 kg body weight and with genotype a⁺ a⁺ b⁺ b⁺ have average 3.4 kg in weight. It means that each contributing allele is contributing 0.6 kg. A male rabbit with genotype a^– a^– b^– b^– is crossed with a female of genotype a⁺ a⁺ b⁺ b⁺. The genotype of F1 progeny will be a⁺ a^– b⁺ b^–. The average weight of F1 progeny will be 1 + 0.6 + 0.6 = 2.2 kg.

105. Autogamy refers to

(a) self-abortion of gametes

(b) flower falling to open

(d) cross-pollination of flowers

Ans. (c)

Sol. Autogamy refers to self-pollination of flowers.

106. Which one of the following plant pathogens has largest genome size?

(a) Phytophthora infestans

(b) Ustilago maydis

(d) Fusarium graminearum

Ans. (a)

Sol. Phytophthora infestans, which is potato late blight fungus has largest genome size among plant pathogens with 240 Mbp.

107. A lectotype refers to

(a) a speciation of the opposite sex to the holotype and designated from among paratypes.

(b) an illustration based on which a new species is described.

(c) a specimen later selected from a group of syntypes to serves as the type specimen for a species, after its original description was published.

(d) a substitute specimen selected to serve as the type specimen of a species after its original description was published, when an original holotype has been lost or destroyed.

Ans. (c)

Sol. A lectotype refers to a specimen later selected from a group of syntypes to serves as the type specimen for a species, after its original description was published.

108. Distance matrix of five species A to E is given below :

Which one of the following topologies represents the accurate species relationships among species A to E if UPGMA clustering method is used for the given data?

(a)

(b)

(c)

(d)

Ans. (d)

Sol. Option (b) correctly represents species relationship among A, B, C, D and E.

109. Select the correct statement. The bark of a woody plant is collectively made up of the following tissues :

(a) primary phloem, primary phloem fibres, pericycle and periderm.

(b) primary xylem, primary phloem fibres, stme cortex, rays and periderm.

(d) secondary phloem, secondary phloem fibres, stem cortex, pericycle and periderm.

Ans. (d)

Sol. The bark of a woody plant is collectively made up of secondary phloem, secondary phloem fibres, stem cortex, pericycle and periderm.

110. Appendix masculina is found in

(a) second abdominal appendages of male palaemon.

(b) second maxillipede of male palaemon.

(d) mandibles of male palaemon.

Ans. (a)

Sol. Appendix masculina is found in second abdominal appendages of male palaemon.

111. Given below is a list of plant species and reproductive forms :

Plant Species Reproductive form

1. Gingko P. Monoecious

2. Conifers Q. Dioecious

3. Poplar

4. Maize

5. Date palm

6. Mango

Which one of the following options correctly matches all the given plant species with their reproductive forms?

(a) P = 1, 3, 5 and Q = 2, 4, 6

(b) P = 1, 2, 5 and Q = 3, 4, 6

(d) P = 3, 4, 6 and Q = 1, 2, 5

Ans. (c, d)

Sol. P. Monoecious : Conifers, Poplar, Maize, Mango.

Q. Dioecious :Gingko, Conifers, Poplar, Date palm

112. The following statements are being made about the archeal cell wall membrane :

P. Archaeal cell walls could stain Gram +ve or Gram –ve depending on the genus.

Q. Archaea cell characterized by Gram +ve staining of the cell wall.

R. Archeal cell walls are susceptible to degradation by lysozyme.

S. Archaeal cell membranes possess branch chain hydrocarbons linked to glycerol by ether links.

Which of the following combinations of statements all correct statements?

(a) P and S

(b) Q and R

(d) Q and S

Ans. (d)

Sol. Archeal species may be Gram-positive or Gram-negative based on their response to Gram staining. The isopernoid hydrocarbon chains are ether linked to the enantiomeric glycerol backbone, glycerol-1-phosphate (G1P). Archaea lack peptidoglycan. In some archaea, cell wall made up of pseudomurein present. It is a heteropolysaccharide consists of repeating disaccharide units. The disaccharide unit is made up of N-acetyltalosaminuronic acid and N-acetylglucosamine linked with a -1, 3 glycosidic bond. As a result of, lysozyme, that affect bacterial cell wall structure and synthesis have no effect on archeal cell walls.

113. The three domain classification of life proposed by Carl Woese divides life forms on the basis of

(a) mitochondrial DNA and membrane structures.

(b) ribosomal rRNA and protein sequences.

(d) presence of single or double membranes.

Ans. (b)

Sol. The three domain classification of life proposed by Carl Woese divides life forms on the basis of ribosomal rRNA and protein sequences.

114. The 50 km Gap is the only major topographic breach in the Western Ghats. This map continues as the Ranotsara Gap in the Angavo escarpment. Which country is the Ranotsara Gap located in?

(a) Sri Lanka

(b) Madagascar

(d) Kenya

Ans. (b)

Sol. Ranotsara Gap located in Madagascar.

115. Given below are the survivorship curves showing the proportion of individuals surviving over time or age. Three generalised typse of curves (a, b and c) are depicted below. Which of the following represent the correct survivorship curve for the given organisms?

(a) a = Elephants, b = Lizards, c = Oysters

(b) a = Oysters, b = Elephants, c = Lizards

(d) a = Oysters, b = Lizards, c = Elephants

Ans. (a)

Sol. The given curve a, b and c re type I, II and III survivorship curve with correct example of Elephants, Lizards and Oysters, respectively.

116. Which one of the following statements is correct with reference to ecotones?

(a) Ecotones are rich in endemic species and only contain species not found in surrounding ecosystems.

(b) Ecotones refer to areas that are under habitat degradation and contain endangered species that are not found in neighbouring communities.

(d) Ecotones are transition areas between two ecosystems and have greater number of species than either of the neighbouring communities.

Ans. (d)

Sol. Ecotones are transition areas between two ecosystems and have greater number of species than either of the neighbouring communities.

117. Given below is a list of natural disturbances.

1. Coral bleaching

2. Rising sea levels

3. Shifts in species distribution

4. Lowering of sea levels

5. Increase in glacial sheets

Which one of the following combinations of disturbances can be attributed to global warming?

(a) 1, 4 and 5

(b) 1, 2 and 3

(d) 3, 4 and 5

Ans. (b)

Sol. Global warming can cause Coral bleaching, rising sea levels and shifts in species distribution

118. A large patch of forested area was devastated by raging fires. After some years, the area was found to recover its species. Which one of the following options best describes the process of re-establishment in the area?

(a) Mosses and lichens grasses shrubs and small plants woody trees.

(b) Grasses woody trees herbs and shrubs mosses and lichens.

(d) Grasses herbs and shrubs woody trees.

Ans. (d)

Sol. After devastation by fire, process of re-establishing occurs as Grasses herbs and shrubs woody trees.

119. According to the classical Lotka-Volterra competition model, which of the following conditions allow for co-existence of two competing species?

(a) Both species are equally capable of inhibiting each other.

(b) Intraspecific competition of each species > interspecific competition.

(d) There is no intraspecific competition in either species.

Ans. (b)

Sol. Two competiting species can co-exist only when intraspecific competiton of each species is more than interspecific competition.

120. Co-existence of several species of birds in an area in possible under the following conditions?

(a) High niche overlap and high niche differentiation.

(b) Low niche overlap and high niche differentiation.

(d) Low niche overlap and low niche differentiation.

Ans. (b)

Sol. Co-existence of several species of birds in an area in possible under low niche overlap and high niche differentiation.

121. Given below are the possible reasons of high probability for extinction of species :

1. Increased homozygosity of alleles.

2. Increased heterozygosity of alleles.

3. Decreasing population sizes.

4. Increasing demographic stochasticity.

5. Decreasing environmental stochasticity.

Which one of the following options represents the correct combination of reasons that can lead to the highest probability of extinction of species?

(a) 2, 3 and 5

(b) 1, 3 and 4

(d) 2, 3 and 4

Ans. (b)

Sol. Increased homozygosity of alleles, decreasing population sizes and increasing demographic stochasticity are the possible reasons of high probability for extinction of species.

122. A field biologist is sampling trees species in a forest area to estimate tree diversity. What method can be employed to decide if his sampling effort is adequate to estimate the tree diversity in the area?

(a) Quadrat method of sampling.

(b) Saturation using species accumulation curves.

(d) Jaccard's dissimilarity coefficient.

Ans. (b)

Sol. A field biologist is sampling trees species in a forest area to estimate tree diversity. Saturation using species accumulation curves. can be employed to decide if his sampling effort is adequate to estimate the tree diversity in the area.

123. The following information refers to eological interactions.

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

(a) P-2, Q-1, R-3, S-4

(b) P-4, Q-3, R-1, S-2

(d) P-3, Q-4, R-1, S-2

Ans. (b)

Sol. P. Bass introduction into aquatic systems : Trophic cascades

Q. Beavers : Keystone species

R. Sea bird (such as puffins) : Bioaccumulation

S. Yellow and black stripes in a wasp : Aposematism

124. The populations of squirrels evolved across two regions separatd by a large geographic barrier. Over a long period of time these populations are reproductively and geographically isolated from each other. This is an example of

(a) sympatric speciation

(b) allopatric speciation

(d) anagenesis

Ans. (b)

Sol. The populations of squirrels evolved across two regions separatd by a large geographic barrier. Over a long period of time these populations are reproductively and geographically isolated from each other. This is an example of allopatric speciation.

125. The term "abominable mystery" was used by Darwin in the context of origin and diversification of

(a) angiosperms

(b) microorganisms

(d) birds

Ans. (a)

Sol. Darwin used the term 'abominable mystery' for sudden appearance of angiosperms during the course of evolution.

126. In Africa "AS" represents a carrier of sickle cell anaemia, where A is the allele for normal haemoglobin and for sickle cell haemoglobin. If the allele S is maintained at a high frequency in some populations, this represents a case of

(a) homozygote advantage

(b) heterozygote advantage

(d) genetic drift

Ans. (b)

Sol. To balance the malaria and sickle cell issue, many populations in Africa are seen with heterozygote combination, the phenomenona is termed as 'heterozygote advantage'.

127. If bird song is selected to maximize broadcast range and to minimise degradation, then according to the "Acoustic Adaptation Hypothesis" which of the following combination of features is likely to be shown by birds singing in dense forests?

(a) Low frequency with narrow bandwidth

(b) High frequency with narrow bandwidth

(d) High frequency with wide bandwidth

Ans. (a)

Sol. To maximize broadcase and minimize degradation the singing should be of low frequency with narrow bandwidth, respectively.

128. According to Hamilton's rule, 'r' is the coefficient of relatedness between two interacting individuals, 'B' is the benefit to the recipient and 'C' is the cost to the donor. Which of the following relationships will result in an altruistic behaviour?

(a) rB = C

(b) rC – B = 0

(d) rC – B > 0

Ans. (c)

Sol. An altruistic behavior will be favoured by natural selection when a certain condition, known as Hamilton's rule, is satisfied. In its simplest version, the rule states that rb > c or –c + rb > 0; where c is the cost incurred by the altruist, b is the benefit received by the recipients of the altruism and r is the coefficient of relatedness between donor and recipient.

129. Felsenstein zone in a phylogenetic tree refers to a region of tree space where

(a) maximum likelihood would be inconsistent.

(b) lineages converge due to shared common ancestry.

(d) maximum parsimony would be inconsistent.

Ans. (d)

Sol. Felsenstein zone in a phylogenetic tree refers to a region of tree space where maximum parsimony would be inconsistent.

130. The figure below shows a gene duplication event followed by a divergence event in species 1 and 2. Based on the details given below determine what is represented by A and B.

(a) A : duplicated genes, B : ancestral genes

(b) A : paralogs, B : ancestral genes

(d) A : paralogs, B : orthologs

Ans. (c)

Sol. By observing the figure where gene duplication and evolutionary divergent between two species is shown, we can say that A is Ortholog and B is Paralog.

131. Given below are proposed analogous structure among organisms :

1. Wings of birds and bats.

2. Wings of bats and tetrapod digits.

3. Tendrils of vitis and tendrils of pumpkin.

4. Tubers of potatoes and sweet potatoes.

5. Fins of fish and flippers of a whale.

Which one of the following options correctly states the analogous structures?

(a) 1, 3 and 4

(b) 2, 3 and 4

(d) 1, 4 and 5

Ans. (d)

Sol. Wings of birds and bats, tubers of potatoes and sweet potatoes and fins of fish and flippers of a whale are examples of Analogous structure.

132. Creationsim is rejected by evolutionary biologists because

(a) it offers no explanation about the origin of adaptation.

(b) it suggests that all species descended from a common ancestor.

(d) supernatural events have not been shown to be very common.

Ans. (a)

Sol. The term creationism refers to belief in special creation. It claim that the universe and lifeforms were created as they exist today by divine action.

133. In Agrobacterium mediated transformation, which one of the following approaches is more likely to generate transgenic plants with incomplete transfer of the passenger gene?

(a) Placement of selection marker gene towards left border and passenger gene towards right border of T-DNA.

(b) Expression of selection marker gene under constitutive promoter and passenger gene under tissue-specific promoter.

(d) Expression of both selection marker gene and passenger gene under constitutive promoters.

Ans. (c)

Sol. T-DNA transfer starts from right border side and ends on left border side. Placing of passenger gene towards left border side make possibility of incomplete transfer of passenger gene.

134. Given below is a schematic representation of a Southern blot performed to identify single copy integration events of the T-DNA among six transgenic plants (T₁-T₆). Which one of the following options represents potential single copy events?

(a) T₁, T₅ and T₆

(b) T₂ and T₃

(d) T₁ only

Ans. (a)

Sol. Single copy insertion can be clearly noticed in the plant T₁, T₅ and T₆ by single band other than of untransformed. The size of the single band is usually different in different independent transformed plants due to differences in integration sites.

135. Gene therapy is a promising tool for addressing several diseases in humans. With respect to the above, which one of the following statements is false?

(a) Gene therapy involves the direct genetic modification of the cells/model to achieve a therapeutic goal.

(b) Current gene therapy is directed at modifying somatic cells.

(c) The only successful gene therapies are those in which cells are removed from a patient, genetically modified and then reintroduced into patients.

(d) Recessively inherited disorders are good targets for gene therapy.

Ans. (c)

Sol. During gene therapy various objectives are achieved. Gene therapy involves the direct genetic modification of the cells/model to achieve a therapeutic goal, current gene therapy is directed at modifying somatic cells and recessively inherited disorders are good targets for gene therapy. In numerous cases, where a particular gene is expressed in a particular organism is introduced in another organism where its affects is to be produced without any further modifications.

136. An experiment was performed to introduce a transgenic trait in a crop plant by Agrobacterium mediated transformation using a transgene construct in which the transgene was expressed using the CaMV 35S promoter. It was observed that expression levels of the transgenic protein were very low in all transgenic plants while transgene mRNA levels were high and variable among different plants. Further, different transgenic lines contained different numbers of the T-DNA insert. The following statements were made to explain the above observation :

P. Variations in the number of T-DNA inserts in different transgenic plants is due to more number of host cells getting infected with the T-DNA.

Q. Low expression levels of the transgenic protein in all transgenic plants could be due to codon usage variations between the host plant and the heterologous source of the transgene.

R. The coding sequence of the transgene contained sequences that destabilized the transgne mRNA.

S. Variation in copy number of T-DNA in different transgenic plants is due to variation in the promoter used to express the transgene.

Which one of the following options represents all correct statements?

(a) P only

(b) Q and R

(d) Q only

Ans. (d)

Sol. An experiment was performed to introduce a transgenic trait in a crop plant by Agrobacterium mediated transformation using a transgene construct in which the transgene was expressed using the CaMV 35S promoter. It was observed that expression levels of the transgenic protein were very low in all transgenic plants while transgene mRNA levels were high and variable among different plants. Further, different transgenic lines contained different numbers of the T-DNA insert. In this case, Low expression levels of the transgenic protein in all transgenic plants could be due to codon usage variations between the host plant and the heterologous source of the transgene.

137. A student added DMEM culture medium which was pink in colour to growing liver cells. Three days later the medium colour was yellow. This indicated

(a) change in cell morphology

(b) change in pH of the medium

(d) lack of antibiotics in the culture

Ans. (b)

Sol. In animal cell, culture pH indicating dye (usually phenol red) is added to monitor pH of the medium. A change in pH is shown by the change in color of the medium.

138. Amongst the following, which one is the most appropriate strategy to sequence and assemble highly repeated regions of a genome?

(a) Shot gun sequencing

(b) Illumina sequencing

(d) Sequencing of BAC libraries

Ans. (d)

Sol. The most appropriate strategy to sequence and assembly highly repeated regions of a genome is using BAC libraries.

139. In the two graphs given below, what do a, b and c refer to :

(a) a = mean, b = median, c = mode

(b) a = median, b = mode, c = mean

(d) a = mean, b = mode, c = median

Ans. (c)

Sol. In both graphs representing positive skew and negative skew, a = mode, b = median, c = mean.

140. Given below are four DNA sequences and a set of forward and reverse primers for PCR amplification.

In the absence of any other factor such as (but not restricted to) T_m, length, percent GC, etc., which one of the above template primers combinations would produce an amplified fragment?

(a) Both P and R

(b) Q only

(d) R only

Ans. (d)

Sol. DNA sequence mentioned in point R 5'-CTTGACTA.....GTACAGTCA-3'

3'-GAACTGAT.....CATGTCAGT-5'

Forward primer must be complementary to 3'-GAACTGAT whereas reverse primer must be complementary to GTACAGTCA-3'. Hence, forward primer and reverse primer mentioned in point R are correct.

141. Given belwo are a few statements related to biological principles and/or techniques :

P. Genetic diversity plays an important role in the identification combiners for heterosis breeding.

Q. Genotyping by sequencing (GBS) can be used to identify allelic diversity but is not useful for construction of linkage maps.

R. Genome editing by sequence specific nucleases (SSNs) in the presence of guide RNAs would result in NHEJ-mediated knock outs and loss of function mutations.

S. In a comparison of synteny and colinearity between diploid and polyploid plant genomes, colinearity is high but synteny is low.

Which one of the following options represents all correct statements?

(a) P and R only

(b) Q and S only

(d) Q only

Ans. (a)

Sol. Genetic diversity plays an important role in the identification combiners for heterosis breeding and genome editing by sequence specific nucleases (SSNs) in the presence of guide RNAs would result in NHEJ-mediated knock outs and loss of function mutations.

142. Given below are statements related to various molecular techniques :

P. During molecular cloning of DNA fragments, a vector and insert molecule digested with two different enzymes can never be ligated with each other.

Q. Only 3' 5' exonucleases and not 5'3' exonucleases can be used for digesting nucleic acids to generate blunt-ended fragments for cloning.

R. In Sanger's dideoxy sequencing method, each reaction consists of a mixture of three dNTPs and one ddNTP.

S. Self-ligation of a vector with compatible ends can be prevented by treatment with alkaline phosphatase.

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

(a) Q and R

(b) P and S

(d) P and Q

Ans.

Sol.

143. Expressing of gene 'A' is a regulated by Mg²⁺. The expression of gene 'A' in untreated (UN) and cells treated with Mg²⁺ (T) was analysed by Northern hybridization (N) and Western blotting (W). A similar exercise was done for a mutant (Mut) which was isolated with a 6 dp deletion in 5'UTR of the transcript of gene 'A'. The following are summary of four possible results that are hypothesized to be obtained :

P. Q.

R. S.

UN = Untreated cells, WT = Wild type cells, T = Cells treated with Mg²⁺, Mut = Cell with mutation in gene A, N = Northern hybridization, W = Western blotting.

If the regulation of gene 'A' expression is controlled only at the level of translation, which of the above profile/s are possible correct representation of the experimental results.

(a) P only

(b) S only

(d) Q and R

Ans. (c)

Sol. Expressing of gene 'A' is a regulated by Mg²⁺. The expression of gene 'A' in untreated (UN) and cells treated with Mg²⁺ (T) was analysed by Northern hybridization (N) and Western blotting (W). A similar exercise was done for a mutant (Mut) which was isolated with a 6 dp deletion in 5'UTR of the transcript of gene 'A'. If the regulation of gene 'A' expression is controlled only at the level of translation, profiles in P and S are correct.

144. To study the effect of temperature on seed germination, 16 seeds of a plant species were selected for an experiment. A total of four temperature treatments were provided to sets of four seeds to study the onset of germination. What would be the within, between and total degrees of freedom, respectively, in an analysis of variance?

(a) 3, 15 and 18

(b) 16, 4 and 20

(d) 15, 3 and 18

Ans. (d)

Sol. Correct option is (d)

145. Given below are some terms in Column A and their corresponding properties/related terms in Column B.

Which one of the following options represents the most appropriate match between all terms of column A and column B?

(a) P-2, Q-4, R-1, S-3

(b) P-3, Q-1, R-4, S-2

(d) P-3, Q-4, R-1, S-2

Ans. (a)

Sol. P. Bulk segregant analysis : Mapping monogenic qualitative traits

Q. NILs : Repeated backcrossing of F1 to recurrent parent

R. Association mapping : QTL analysis of wider genetic diversity using fewer individuals

S. SNPs : Co-dominant markers

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Previous Year Question Paper with Solution.