PART – B
51. A patient is suffering from an auto-immune disorder. Exome analysis has revealed a mutation in the gene ‘AIRE’. Which one of the following biological processes is likely to be affected in this patient?
a. Positive selection of thymocytes
b. Negative selection of thymocytes
c. Affinity maturation
d. Dendritic cell development
52. Which one of the following genes is mutated in nude mice?
53. Which one of the following statements is TRUE for long non-coding RNAs?
a. They are less than 22 base pair
b. They are processed in the nucleus by RISC complex
c. They have > 300 amino acid open reading frame
d. They may have a poly-A tail
54. Which kind of post-translationally modified protein targets are recognized by
Bromodomain containing proteins?
a. Acetylated protein
b. Glycosylated protein
c. Ubiqutinylated protein
d. Sumoylated protein
55. When dissolved oxygen is lower than the critical concentration in mammalian cell
culture systems, cell viability declines because of:
a. Complete glutamine oxidation
b. Decrease in specific lactate production from glucose
c. Incomplete glutamine oxidation and increase in lactate production from
d. Accumulation of ammonia
56. Combination of high temperature during processing, low temperature during storage,
and increasing the acidity for prevention of food contamination is known as:
a. Stumbling technology
b. Mixed preservation approach
c. High pressure food preservation
d. Hurdle technology
57. The production of ethanol rather than biomass by yeast cells at high concentration of
glucose is known as:
a. Warburg effect
b. Simpson’s effect
c. Crabtree effect
d. Olivosky’s effect
58. Anhidrotic dysplasia is a condition in which development of sweat glands is prevented. It is caused by mutation present on the X chromosome. A heterozygous female for this allele will:
a. Show complete absence of sweat glands.
b. Have normal phenotype
c. Show mosaic pattern of presence and absence of sweat glands
d. Show increased physiological activity of sweat glands
59. The combination of numbered terms that completes all of the following statement is:
i. Transport through the phloem is __1___ while transport through Xylem is __2__
ii. Loading of sugar into the phloem is __3___ at the source
iii. Movement of water out of the phloem at the sink is –4–
a. 1-bidirectional, 2-unidirectional, 3-by active transport, 4-by osmosis
b. 1-by osmosis, 2-by turgor pressure, 3- by passive transport, 4-bidirectional
c. 1-unidirectional, 2-bidirectional, 3-by diffusion, 4-unidirectional
d. 1-by diffusion, 2-unidirectional, 3-bidirectional, 4-by osmosis
60. A plant with orange flowers was self-pollinated. In the F1 progeny, we obtained 38 plants producing red flowers, 80 plants producing orange flowers and 41 plants producing yellow flowers. The likely explanation for the above observation is that:
a. the gene for flower colour shows incomplete dominance.
b. flower colour is a polygenic trait controlled by 3 genes.
c. the gene for flower colour is epistatic to another gene.
d. the trait of flower colour is maternally inherited.
61. Based on equal probability of any base occurrence in a genome, what should be the minimum length of a probe to bind specifically on a single locus on a bacterial genome of 1 Mbp?
a. 6 bases
b. 15 bases
c. 10 bases
d. 4 bases
62. Which one of the following techniques can be used to study transient protein – protein interactions in a live cell?
a. Pull-down assay
c. Surface Plasmon Resonance
d. Forster Resonance Energy Transfer
63. Which one of the following graphs correctly represents unfolding of a protein in
presence of increasing concentration of urea?
64. A tRNA containing an anticodon for leucine was charged with leucine. Subsequently, the attached leucine was chemically modified to arginine. This tRNA will incorporate:
a. Arginine against codon of arginine in mRNA.
b. Leucine against codon of arginine in mRNA.
c. Arginine against codon of leucine in mRNA.
d. Leucine against codon of leucine in mRNA
65. Which one of the following statements regarding base excision DNA repair system is FALSE?
a. It can be triggered by damaged DNA.
b. The pol pathway facilitates replacement of a long polynucleotide stretch of DNA.
c. The enzymes that remove bases from DNA are glycosylases and lyases.
d. Damaged DNA that has not been repaired causes stalling of DNA polymerase III.
66. Which one of the following result is expected when a mammalian cell in S phase is fused with another in G2?
a. G2 phase nucleus will wait for the S phase nucleus to complete the replication and both the nuclei simultaneously enter into M phase.
b. S phase nucleus would immediately enter into G2 phase without completing the replication phase.
c. Both the nuclei would follow their corresponding cell cycle without influencing each other.
d. Due to influence of S phase promoting factor, G2 phase nucleus will enter into S phase.
67. Following statements are about chromatin organisation in eukaryotes:
i. The length of DNA per nucleosome varies for individual tissue or species.
ii. Typical nucleosomal packaging pattern is strictly maintained across the genome of an organism.
iii. While wrapping around the histone core particle, uniform structure of DNA is maintained.
iv. Histone tail mediated internucleosomal contact is one of the essential factors to achieve the 30 nm fibre structure.
Select the correct combination of statements.
a. i and iii
b. ii and iii
c. i and iv
d. iii and iv
68. Which one of the following techniques can be utilized to study both protein–peptide and protein–DNA interactions?
a. DNA footprinting
b. 2D-gel electrophoresis
c. Phage display
d. ChIP-on-chip assay
69. In genomic DNA denaturation and renaturation experiments, which one of the following regions would renature the earliest?
a. Single-copy gene
b. Satellite DNA
d. Multi copy gene families
70. Which one of the following represents an autonomous retrotransposon?
71. Thallium-208 has a half-life of 3.053 min. How long will a sample containing 120.0 µCi of Thallium-208 take to decay to 7.50 µCi?
a. 6.11 min.
b. 9.36 min.
c. 12.21 min.
d. 18.46 min.
72. Injection of nanos transcripts at the anterior end of a fertilized Drosophila egg is expected to develop in an embryo with:
a. Two heads at both the ends.
b. Two tails at both the ends.
c. A tail in middle and two heads at both the ends.
d. A head in middle and two tails at both the ends.
73. If nondisjunction of a chromosome occurs in meiosis II, what will be the product at the completion of meiosis?
a. All the gametes will be diploid
b. Two gametes will be n + 1, and two will be n – 1
c. One gamete will be n + 1, one will be n – 1, and two will be n
d. Two of the four gametes will be haploid, and two will be diploid
74. Which one of the following changes occurs in a directionally migrating eukaryotic cell?
a. The ER is fragmented.
b. The mitochondrial membrane potential drops.
c. The nucleus moves towards the back and behind the Golgi.
d. The Golgi is fragmented.
75. Underwinding or overwinding of circular dsDNA generates supercoils only when it does NOT have any of the following:
b. repeat sequences
c. G:C rich regions
d. A:T rich regions
76. CRISPR/Cas9 is an example of bacterial adaptive immunity. The transcription of CRISPR loci generates small crispr-RNAs (crRNA) to specifically target viral DNA, but not CRISPR loci, by forming complex with guide RNA and Cas9 nuclease. This prevention of autoimmunity is due to the:
a. absence of protospacer adjacent motif sequence in CRISPR loci.
b. absence of DNA sequence complementary to crRNA in CRISPR loci.
c. absence of DNA sequence complementary to guide RNA in CRISPR loci.
d. methylation of CRISPR loci.
77. The type of transport that does NOT reach Vmax is:
a. Simple diffusion across lipid bilayer
b. Facilitated diffusion via uniporters
c. Movement of ions through ion channels
d. Primary active transport via ATP powered pumps
78. What is the minimum number of tRNAs required to recognize all six codons of serine (UCU, UCA, UCG, UCC, AGU and AGC)?
79. Which one of the following statements about signal recognition particles (SRPs) is INCORRECT?
a. contains RNA and protein.
b. is an integral membrane protein.
c. docks with a receptor on the surface of the ER membrane.
d. binds to localization signal at the N-terminus of the emerging polypeptide chain.
80. Which one of the following materials is a bioplastic?
81. Labeled circular single stranded DNA and linear short DNA (oligo) were annealed to form a product shown in figure I. Helicase assay was performed using the annealed product and three proteins A, B, C. Below is the gel profile of the results (figure II).
Based on the results identify the protein with helicase activity?
a. protein A
b. protein B
c. Protein C
d. Both Protein A and C
82. Protein X exists in both GTP-bound and GDP-bound forms. When this protein was purified, it was always GDP-bound. Proteins Y, W and V were added separately in an experiment along with GTP. The results of the experiment are depicted in the following figure:
Which one of the following could be the right conclusion of the results?
a. Protein Y is GAP for protein X
b. Protein Y is GEF for protein X
c. Protein W is GEF for protein X
d. Protein V is GEF for protein X
83. In a class, students were divided into 3 different groups and each group was given different DNA sample to find the melting temperature (Tm). All the groups observed same Tm for their samples. This is because:
a. They got different DNA samples from the same organism with different lengths and same GC content.
b. They got different DNA samples with same lengths and different GC contents.
c. They got different DNA samples with same length and same GC content.
d. They got different DNA samples from different organisms with different length and same GC content.
84. For efficient translation of certain eukaryotic mRNAs under many physiological and pathological stress conditions, the small subunit of ribosome binds to the mRNA at the:
a. 5‵ Cap.
b. Internal ribosome entry sites.
c. Secondary structure at 3‵ UTR.
d. Initiation codon.
85. For identifying the distribution of a specific protein in a tissue, which one of the following types of immunofluorescence microscopic methods has attained the highest level of resolution?
a. Indirect immunofluorescence microscopy
b. Confocal microscopy
c. Confocal microscopy with deconvolution
d. Wide angle microscopy with deconvolution
86. Which one of the following sets of protein factors, named as Yamanaka factors, can be used to convert mammalian somatic cells into induced pluripotent stem cells?
a. Oct3/4, Sox2, Klf4, c-Myc
b. c-fos, nestin, TGF, c-jun
c. Oct3, snail, FGF, nanos
d. Hstf, vimentin, ets, ras
87. Hayflick limit of mammalian cells refers to which one of the following?
a. Cells in primary cell culture undergo senescence after 50-60 passages.
b. Primary cells cultured in vitro do not cross the limit of cell transformation.
c. Cell lines when cultured in vitro have a limit for their surface to volume ratio.
d. Malignant cell lines undergo senescence after 50-60 passages.
88. Midblastula transition is a phenomenon that occurs during early development in certain organisms. It refers to:
a. Transition from maternal to zygotic gene expression
b. Transition of morphology during midblastula stage
c. Transition from two germ layer embryo to three germ layer embryo
d. Transition of blastula to gastrula
89. Under which of the following circumstances do T cells develop anergy?
a. With the expression of CD69 on T cells.
b. When the CD4/ CD8 molecules present on T cell surfaces do not recognize
self MHC II/MHC I molecules.
c. When the MHCII molecules present on antigen presenting cells bind to the
peptides with less avidity.
d. When co-stimulatory molecules present on the antigen presenting cells fail to
interact with T cells.
90. A chemist synthesized a new chemical X which is highly mutagenic. He also tested the
capacity of mutation induced by X to be reversed by other known mutagens and
obtained the following results:
Which one of the following conclusions is appropriate?
a. X causes transversion
b. X causes transition
c. X causes single-base insertion
d. X causes single-base deletion
91. What would be the best assay to detect and quantify a small and low abundant peptide
in a biological sample?
a. Lowry’s assay
92. A mutation in the coding region of a mammalian gene leads to the loss of a single amino acid at the N-terminus of the nascent polypeptide. This is possible when:
A. The mutation occurs at 3’-end of coding strand.
B. The mutation leads to shift of ribosome binding site.
C. the first two codons code for methionine.
D. the mutation leads to the introduction of premature stop codon.
93. A scientist performs a series of experiments to determine the recombination frequencies between the following genes. He acquires the following data:
P – Q: 3%; Q – R: 2%; R – S: 13%; P – S: 8%
Which one of the following represents the correct order of genes?
94. You have two tubes containing bacteriophage labelled with radioactive phosphorous (tube A) and radioactive Sulphur (tube B) that are devoid of bacteria. You use these bacteriophage to infect separate E. coli cultures. After infection you separate bacteria from the virus and check them for radioactivity. You will find:
a. Radioactivity in both bacterial samples.
b. Radioactivity in none of them as bacteria have been totally separated from the
c. Radioactivity in bacteria infected with viruses from tube A.
d. Radioactivity in bacteria infected with viruses from tube B.
95. Colour blindness (B) in human follows sex-linked recessive mode of inheritance. If a couple with normal colour vision have a colour-blind son. What will be the genotypes of the parents?
a. XbXb and XbY
b. XBXb and XBY
c. XbXb and XBY
d. XBXB and XbY
96. If the allele A is incompletely dominant over allele a, what is expected in a progeny of two heterozygous parents?
a. Same phenotypic and genotypic ratios
b. 2:1 phenotypic ratio
c. 3:1 phenotypic ratio
d. 2:1 ratio of homozygous dominant and intermediate phenotypes
97. An experiment involves formation of RNA-DNA hybrid. Which one of the following enzymes could be utilized to degrade only the RNA strand from the RNA-DNA hybrid?
a. Micrococcal nuclease
b. S1 nuclease
c. RNase H
d. RNase P
98. If the intracellular pH of a cell becomes basic, which one of the following will help reduce the pH?
a. Export of Cland import of HCO3-
b. Import of Cland export of HCO3-
c. Import of Na+and HCO3- and export of Cl
d. Export of Na+and Cl
99. Proteins can act as excellent buffers because of:
a. The wide range of pKa values of side chains found within the proteins.
b. The ability of the terminal regions of the protein to accept or donate H+ ions.
c. Their hydrogen-bonding capabilities in forming secondary & tertiary structures.
d. The ease with which H+ & OHions can be absorbed once the protein is hydrolyzed.
100. Which one of the following statements is INCORRECT in relation to reverse phase chromatography?
a. The solutes elute with decreasing order of polarity.
b. The stationary phase surface covering the silica particles involves non-polar functional groups.
c. The solutes elute with increasing order of molecular weight.
d. The pH of the mobile phase has a profound influence on retention, selectivity and separation.