Hello friends, in toaday's articlw we see the MCQ's of Nucleic Acid.
Nucleic Acid MCQ’s
1. A
nucleoside consists of
(A) Nitrogenous
base
(B) Purine or pyrimidine base + sugar
(C) Purine or
pyrimidine base + phosphorous
(D) Purine +
pyrimidine base + sugar + phosphorous
2. A
nucleotide consists of
(A) A
nitrogenous base like choline
(B) Purine + pyrimidine base + sugar +
phosphorous
(C) Purine or
pyrimidine base + sugar
(D) Purine or
pyrimidine base + phosphorous
3. A
purine nucleotide is
(A) AMP
(B) UMP
(C) CMP
(D) TMP
4. A
pyrimidine nucleotide is
(A) GMP
(B) AMP
(C) CMP
(D) IMP
5. Adenine
is
(A) 6-Amino
purine
(B) 2-Amino-6-oxypurine
(C) 2-Oxy-4-aminopyrimidine
(D) 2,
4-Dioxypyrimidine
6. 2,
4-Dioxypyrimidine is
(A) Thymine
(B) Cystosine
(C) Uracil
(D) Guanine
7. The
chemical name of guanine is
(A) 2,4-Dioxy-5-methylpyrimidine
(B)
2-Amino-6-oxypurine
(C) 2-Oxy-4-aminopyrimidine
(D) 2,
4-Dioxypyrimidine
8. Nucleotides
and nucleic acids concentration are often also expressed in terms of
(A) ng
(B) mg
(C) meq
(D) OD at 260 nm
9. The
pyrimidine nucleotide acting as the high energy intermediate is
(A) ATP
(B) UTP
(C) UDPG
(D) CMP
10. The
carbon of the pentose in ester linkage with the phosphate in a nucleotide
structure is
(A) C1
(B) C3
(C) C4
(D) C5
11. Uracil
and ribose form
(A) Uridine
(B) Cytidine
(C) Guanosine
(D) Adenosine
12. The
most abundant free nucleotide in mammalian cells is
(A) ATP
(B) NAD
(C) GTP
(D) FAD
13. The
mean intracellular concentration of ATP in mammalian cell is about
(A) 1 mM
(B) 2 mM
(C) 0.1 mM
(D) 0.2 mM
14. The
nucleic acid base found in mRNA but
not in DNA is
(A) Adenine
(B) Cytosine
(C) Guanine
(D) Uracil
Read more MCQ's of carbohydrates
15. In RNA moleule ‘Caps’
(A) Allow tRNA
to be processed
(B) Are unique to eukaryotic mRNA
(C) Occur at
the 3’ end of tRNA
(D) Allow
correct translation of prokaryotic mRNA
16. In contrast
to eukaryotic mRNA, prokaryotic mRNA
(A) Can be polycistronic
(B) Is synthesized with introns
(C) Can only be
monocistronic
(D) Has a poly
A tail
17. The
size of small stable RNA ranges from
(A) 0-40
nucleotides
(B) 40-80
nucleotides
(C) 90-300 nucleotides
(D) More
than 320 nucleotides
18. The
number of small stable RNAs per cell
ranges from
(A) 10-50,000
(B) 50,000-1,00,000
(C) 1,00,000-10,00,000
(D) More
than 10 lakhs
19. Molecular
weight of heterogenous nuclear RNA (hnRNA) is
(A) More than 107
(B) 105
to 106
(C) 104
to 105
(D) Less than
104
20. In RNA
molecule guanine content does not necessarily equal its cytosine content nor
does its adenine content necessarily equal its uracil
content since it is a
(A) Single strand molecule
(B) Double
stranded molecule
(C) Double
stranded helical molecule
(D) Polymer of
purine and pyrimidine ribonucleotides
21. The
nitrogenous base present in the RNA molecule is
(A) Thymine
(B) Uracil
(C) Xanthine
(D)
Hypoxanthine
22. RNA
does not contain
(A) Uracil
(B) Adenine
(C) Thymine
(D) Ribose
23. The
sugar moiety present in RNA is
(A) Ribulose
(B) Arabinose
(C) Ribose
(D) Deoxyribose
24. In RNA
molecule
(A) Guanine
content equals cytosine
(B) Adenine
content equals uracil
(C) Adenine
content equals guanine
(D) Guanine content does not necessarily equal its
cytosine content.
25. Methylated
purines and pyrimidines are characteristically present in
(A) mRNA
(B) hnRNA
(C) tRNA
(D) rRNA
26. Thymine
is present in
(A) tRNA
(B) Ribosomal
RNA
(C) Mammalian
mRNA
(D) Prokaryotic
mRNA
27. The
approximate number of nucleotides in tRNA molecule is
(A) 25
(B) 50
(C) 75
(D) 100
28. In
every cell, the number of tRNA molecules is at least
(A) 10
(B) 20
(C) 30
(D) 40
29. The
structure of tRNA appears like a
(A) Helix
(B) Hair pin
(C) Clover leaf
(D) Coil
30. Although
each specific tRNA differs from the others in its sequence of nucleotides, all
tRNA molecules contain a base paired stem that terminates in the sequence CCA
at
(A) 3′ Termini
(B) 5′ Termini
(C) Anticodon
arm
(D) 3′5′
-Termini
31. Transfer
RNAs are classified on the basis of the number of base pairs in
(A) Acceptor
arm
(B) Anticodon
arm
(C) D arm
(D) Extra arm
32. In tRNA
molecule D arm is named for the presence of the base:
(A) Uridine
(B)
Pseudouridine
(C)
Dihydrouridine
(D) Thymidine
33. The
acceptor arm in the tRNA molecule has
(A) 5 Base
pairs
(B) 7 Base pairs
(C) 10 Base
pairs
(D) 20 Base
pairs
34. In tRNA
molecule, the anticodon arm possesses
(A) 5 Base pairs
(B) 7 Base
pairs
(C) 8 Base
pairs
(D) 10 Base
pairs
35. The T ψ
C arm in the tRNA molecule possesses the sequence
(A) T, pseudouridine and C
(B) T, uridine
and C
(C) T,
dihydrouridine and C
(D) T, adenine
and C
36. Double
helical structure model of the DNA was proposed by
(A) Pauling and
Corey
(B) Peter
Mitchell
(C) Watson and Crick
(D) King and
Wooten
37. DNA
does not contain
(A) Thymine
(B) Adenine
(C) Uracil
(D) Deoxyribose
38. The
sugar moiety present in DNA is
(A) Deoxyribose
(B) Ribose
(C) Lyxose
(D) Ribulose
39. DNA
rich in A-T pairs have
(A) 1
Hydrogen bond
(B) 2 Hydrogen
bonds
(C) 3
Hydrogen bonds
(D) 4 Hydrogen bonds
40. In DNA
molecule
(A) Guanine
content does not equal cytosine content
(B) Adenine content does not equal
thymine content
(C) Adenine
content equals uracil content
(D) Guanine content equals cytosine content
41. DNA
rich in G-C pairs have
(A) 1
Hydrogen bond
(B) 2 Hydrogen bonds
(C) 3 Hydrogen bonds
(D) 4 Hydrogen bonds
42. The
fact that DNA bears the genetic information of an organism implies that
(A) Base
composition should be identical from species to species
(B) DNA base
composition should charge with age
(C) DNA from different tissues in the same organism should usually have the same
base
composition
(D) DNA base
composition is altered with nutritional state of an organism
43. The
width (helical diameter) of the double helix in B-form DNA in nm is
(A) 1
(B) 2
(C) 3
(D) 4
44. The
number of base pair in a single turn of B-form DNA about the axis of the molecule
is
(A) 4
(B) 8
(C) 10
(D) 12
45. The
distance spanned by one turn of B-form DNA is
(A) 1.0 nm
(B) 2.0 nm
(C) 3.0 nm
(D) 3.4 nm
46. In a
DNA molecule the thymine concentration is 30%, the guanosine concentration will
be
(A) 10%
(B) 20%
(C) 30%
(D) 40%
47. IN a
DNA molecule, the guanosine content is 40%, the adenine content will be
(A) 10%
(B) 20%
(C) 30%
(D) 40%
48. An increased
melting temperature of duplex DNA results from a high content of
(A) Adenine +
Guanine
(B) Thymine + Cytosine
(C) Cytosine + Guanine
(D) Cytosine +
Adenine
49. A
synthetic nucleotide analogue, 4-hydroxypyrazolopyrimidine is used in the
treatment of
(A) Acute
nephritis
(B) Gout
(C) Cystic
fibrosis of lung
(D) Multiple
myeloma
50. A
synthetic nucleotide analogue, used in the chemotherapy of cancer and viral
infections is
(A) Arabinosyl cytosine
(B) 4-Hydroxypyrazolopyrimidine
(C) 6-Mercaptopurine
(D) 6-Thioguanine
51. Histamine
is formed from histidine by the enzyme histidine decarboxylase in the
presence of
(A) NAD
(B) FMN
(C) HS-CoA
(D) B6-PO4
52. Infantile
convulsions due to lesser formation of gamma amino butyric acid
from glutamic acid is seen in the de-ficiency of
(A)
Glutamate-dehydrogenase
(B) Pyridoxine
(C) Folic acid
(D) Thiamin
53. Which
of the following amino acids produce a vasoconstrictor on decarboxylation?
(A) Histidine
(B) Tyrosine
(C) Threonine
(D) Arginine
54. The
degradation of RNA by pancreatic ribonuclease produces
(A) Nucleoside
2-Phosphates
(B) Nucleoside
5′-phosphates
(C)
Oligonucleosides
(D) Nucleoside 3′-phosphate and oligonucleotide
55. Intestinal
nucleosidases act on nucleosides and produce
(A) Purine base
only
(B) Phosphate
only
(C) Sugar only
(D) Purine or pyrimidine bases and sugars
56. In
purine biosynthesis carbon atoms at 4 and 5 position and N at 7 position are contributed
by
(A) Glycine
(B) Glutamine
(C) Alanine
(D) Threonine
57. N10-formyl
and N5N10-methenyl tetrahydrofolate contributes purine
carbon atoms at position
(A) 4 and 6
(B) 4 and 5
(C) 5 and 6
(D) 2 and 8
58. In
purine nucleus nitrogen atom at 1 position is derived from
(A) Aspartate
(B) Glutamate
(C) Glycine
(D) Alanine
59. The key
substance in the synthesis of purine, phosphoribosyl pyrophosphate is formed by
(A) α-D-ribose 5-phosphate
(B) 5-phospho β-D-ribosylamine
(C) D-ribose
(D) Deoxyribose
60. In
purine biosynthesis ring closure in the molecule formyl glycinamide
ribosyl-5-phosphate requires the cofactors:
(A) ADP
(B) NAD
(C) FAD
(D) ATP and Mg++
61. Ring
closure of formimidoimidazole carboxamide ribosyl-5-phosphate yields the first
purine nucleotide:
(A) AMP
(B) IMP
(C) XMP
(D) GMP
62. The
cofactors required for synthesis of adenylosuccinate are
(A) ATP, Mg++
(B) ADP
(C) GTP, Mg++
(D) GDP
63. Conversion
of inosine monophosphate to
xanthine monophosphate is catalysed by
(A) IMP dehydrogenase
(B) Formyl
transferase
(C)
Xanthine-guanine phosphoribosyl transferase
(D) Adenine
phosphoribosyl transferase
64. Phosphorylation
of adenosine to AMP is catalysed by
(A) Adenosine kinase
(B)
Deoxycytidine kinase
(C)
Adenylosuccinase
(D)
Adenylosuccinate synthetase
65. The
major determinant of the overall rate of denovo purine nucleotide biosynthesis
is the concentration of
(A) 5-phosphoribosyl 1-pyrophosphate
(B) 5-phospho
β-D-ribosylamine
(C) Glycinamide
ribosyl-5-phosphate
(D) Formylglycinamide
ribosyl-5-phosphate
66. An
enzyme which acts as allosteric regulator and sensitive to both phosphate concentration
and to the purine nucleotides is
(A) PRPP synthetase
(B) PRPP
glutamyl midotransferase
(C) HGPR Tase
(D) Formyl
transferase
67. PRPP
glutamyl amidotransferase, the first enzyme uniquely committed to purine
synthesis is feed back inhibited by
(A) AMP
(B) IMP
(C) XMP
(D) CMP
68. Conversion
of formylglycinamide ribosyl 5-phosphate to formyl-glycinamide ribosyl-5-phosphate
is inhibited by
(A) Azaserine
(B)
Diazonorleucine
(C) 6-Mercaptopurine
(D)
Mycophenolic acid
69. In the
biosynthesis of purine nucleotides the AMP feed back regulates
(A)
Adenylosuccinase
(B) Adenylosuccinate synthetase
(C) IMP
dehydrogenase
(D) HGPR Tase
70. 6-Mercapto
purine inhibits the conversion
of
(A) IMP→ XMP
(B) Ribose 5
phosphate → PRPP
(C) PRPP →
5-phospho → β -D-ribosylamine
(D) Glycinamide
ribosyl 5-phosphate → formylglycinamide ribosyl-5-phosphate
71. Purine
biosynthesis is inhibited by
(A) Aminopterin
(B) Tetracyclin
(C)
Methotrexate
(D)
Chloramphenicol
72. Pyrimidine
and purine nucleoside biosynthesis share a common precursor:
(A) PRPP
(B) Glycine
(C) Fumarate
(D) Alanine
73. Pyrimidine
biosynthesis begins with the formation from glutamine, ATP and CO2,
of
(A) Carbamoyl
aspartate
(B) Orotate
(C) Carbamoyl phosphate
(D)
Dihydroorotate
74. The two
nitrogen of the pyrimidine ring are contributed by
(A) Ammonia and
glycine
(B) Asparate and carbamoyl phosphate
(C) Glutamine
and ammonia
(D) Aspartate
and ammonia
75. A
cofactor in the conversion of dihydroorotate to orotic acid, catalysed by the enzyme
dihydroorotate dehydrogena-
se is
(A) FAD
(B) FMN
(C) NAD
(D) NADP
76. The
first true pyrimidine ribonucleotide synthesized is
(A) UMP
(B) UDP
(C) TMP
(D) CTP
77. UDP and
UTP are formed by phosphorylation from
(A) AMP
(B) ADP
(C) ATP
(D) GTP
78. Reduction
of ribonucleotide diphosphates (NDPs) to their corresponding
deoxyribonucleotide diphosphates (dNDPs) involves
(A) FMN
(B) FAD
(C) NAD
(D) NADPH
79. Conversion
of deoxyuridine monophosphate to thymidine monophosphate is
catalysed by the enzyme:
(A)
Ribonucleotide reductase
(B) Thymidylate synthetase
(C) CTP
synthetase
(D) Orotidylic
acid decarboxylase
80. d-UMP
is converted to TMP by
(A) Methylation
(B)
Decarboxylation
(C) Reduction
(D) Deamination
81. UTP is
converted to CTP by
(A) Methylation
(B)
Isomerisation
(C) Amination
(D) Reduction
82. Methotrexate
blocks the synthesis of thymidine monophosphate by inhibitin the activity of
the enzyme:
(A) Dihydrofolate reductase
(B) Orotate
phosphoribosyl transferase
(C) Ribonucleotide
reductase
(D)
Dihydroorotase
83. A
substrate for enzymes of pyrimidine nucleotide biosynthesis is
(A) Allopurinol
(B) Tetracylin
(C)
Chloramphenicol
(D) Puromycin
84. An
enzyme of pyrimidine nucleotide biosynthesis sensitive to allosteric regulation
is
(A) Aspartate transcarbamoylase
(B)
Dihydroorotase
(C)
Dihydroorotate dehydrogenase
(D) Orotidylic
acid decarboxylase
85 An
enzyme of pyrimidine nucleotides biosynthesis regulated at the genetic level by
apparently coordinate repression and derepression is
(A) Carbamoyl phosphate synthetase
(B)
Dihydroorotate dehydrogenase
(C) Thymidine
kinase
(D)
Deoxycytidine kinase
86. The
enzyme aspartate transcarbamoylase of pyrimidine biosynthesis is inhibited by
(A) ATP
(B) ADP
(C) AMP
(D) CTP
87. In
humans end product of purine catabolism is
(A) Uric acid
(B) Urea
(C) Allantoin
(D) Xanthine
88. In
humans purine are catabolised to uric acid due to lack of the enzyme:
(A) Urease
(B) Uricase
(C) Xanthine
oxidase
(D) Guanase
89. In
mammals other than higher primates uric acid is converted by
(A) Oxidation to allantoin
(B) Reduction
to ammonia
(C) Hydrolysis
to ammonia
(D) Hydrolysis
to allantoin
90. The
correct sequence of the reactions of catabolism of adenosine to uric acid is
(A)
Adenosine→hypoxanthine→xanthine→uric acid
(B)
Adenosine→xanthine→inosine→uric acid
(C) Adenosine→inosine→hypoxanthine→ xanthine uric
acid
(D) Adenosine→xanthine→inosine→hypoxanthine
uric acid
91. Gout is
a metabolic disorder of catabolism
of
(A) Pyrimidine
(B) Purine
(C) Alanine
(D)
Phenylalanine
92. Gout is
characterized by increased plasma
levels of
(A) Urea
(B) Uric acid
(C) Creatine
(D) Creatinine
93. Lesch-Nyhan
syndrome, the sex linked recessive disorder is due to the lack of the
enzyme:
(A) Hypoxanthine-guanine phosphoribosyl
transferse
(B) Xanthine
oxidase
(C) Adenine
phosphoribosyl transferase
(D) Adenosine
deaminase
94. Lesch-Nyhan
syndrome, the sex linked, recessive absence of HGPRTase, may lead
to
(A) Compulsive self destructive behaviour with
elevated levels of urate in serum
(B)
Hypouricemia due to liver damage
(C) Failure to
thrive and megaloblastic anemia
(D) Protein
intolerance and hepatic encephalopathy
95. The
major catabolic product of pyrimidines in human is
(A) β-Alanine
(B) Urea
(C) Uric acid
(D) Guanine
96. Orotic
aciduria type I reflects the deficiency of enzymes:
(A) Orotate phosphoribosyl transferase and
orotidylate decarboxylase
(B)
Dihydroorotate dehydrogenase
(C)
Dihydroorotase
(D) Carbamoyl
phosphate synthetase
97. Orotic
aciduria type II reflects the deficiency of the enzyme:
(A) Orotate
phosphoribosyl transferase
(B) Orotidylate decarboxylase
(C)
Dihydroorotase
(D)
Dihydroorotate dehydrogenase
98. An
autosomal recessive disorder, xanthinuria is due to deficiency of the enzymes:
(A) Adenosine
deaminase
(B) Xanthine oxidase
(C) HGPRTase
(D)
Transaminase
99. Enzymic
deficiency in β-aminoisobutyric aciduria is
(A) Adenosine
deaminase
(B) Xanthine
oxidase
(C) Orotidylate
decarboxylase
(D) Transaminase
100. Polysomes
lack in
(A) DNA
(B) mRNA
(C) rRNA
(D) tRNA
101. Genetic
information flows from
(A) DNA to DNA
(B) DNA to RNA
(C) RNA to
cellular proteins
(D) DNA to
cellular proteins
102. Genetic
code is
(A) Collection of codon
(B) Collection of amino acids
(C) Collection
of purine nucleotide
(D) Collection
of pyrimidine nucleotide
103. Degeneracy
of genetic code implies that
(A) Codons do
not code for specific amino acid
(B) Multiple codons must decode the same amino acids
(C) No
anticodon on tRNA molecule
(D) Specific
codon decodes many amino acids
104. Genetic
code is
(A) Overlapping
(B) Non-overlapping
(C) Not
universal
(D) Ambiguous
105. mRNA is
complementary to the nucleotide sequence of
(A) Coding strand
(B) Ribosomal
RNA
(C) tRNA
(D) Template
strand
106. In DNA
replication the enzyme required in the first step is
(A) DNA
directed polymerase
(B) Unwinding proteins
(C) DNA
polymerase
(D) DNA ligase
107. The
smallest unit of DNA capable of coding for the synthesis of a polypeptide is
(A) Operon
(B) Repressor
gene
(C) Cistron
(D) Replicon
108. Termination
of the synthesis of the RNA molecule is signaled by a sequence in the
template strand of the DNA molecule, a signal that is
recognized by a termination protein, the
(A) Rho (ρ) factor
(B) σ factor
(C) δ factor
(D) ε factor
109. After
termination of the synthesis of RNA molecule, the core enzymes separate from the
DNA template. The core enzymes then recognize a promoter at which the syn-
thesis of a new RNA molecule commenc-
es, with the assistance of
(A) Rho (ρ)
factor
(B) δ factor
(C) β factor
(D) σ factor
110. In the
process of transcription in bacterial
cells
(A) Initiation
requires rho protein
(B) RNA
polymerase incorporates methylated bases in correct sequence
(C) Both the sigma unit and core enzymes of RNA polymerase are required for accurate
promotor site binding
(D) Primase is
necessary for initiation
111. The
correct statement concerning RNA and
DNA polymerases is
(A) RNA
polymerase use nucleoside diphosphates
(B) RNA
polymerase require primers and add bases at 5’ end of the growing
polynucleotide
chain
(C) DNA
polymerases can add nucleotides at both ends of the chain
(D) All RNA and DNA polymerases can add nucleotides only at the 3’ end of the
growing
polynucleotide
chain
112. The
eukaryotic nuclear chromosomal DNA
(A) Is a linear and unbranched molecule
(B) Is not associated with a specific
membranous organelle
(C) Is not
replicated semiconservatively
(D) Is about of
the same size as each prokaryotic chromoses
113. The
function of a repressor protein in an operon system is to prevent synthesis by binding
to
(A) The
ribosome
(B) A specific region of the operon preventing transcription
of structural genes
(C) The RNA
polymerase
(D) A specific
region of the mRNA preventing translation to protein
114. All
pribnow boxes are variants of the sequence:
(A) 5′-TATAAT -3′
(B) 5′-GAGCCA
-3′
(C) 5′-UAACAA
-3′
(D) 5′-TCCTAG
-3′
115. 5’-Terminus
of mRNA molecule is capped with
(A) Guanosine
triphosphate
(B)
7-Methylguanosine triphophate
(C) Adenosine
triphosphate
(D) Adenosine
diphosphate
116. The
first codon to be translated on mRNA
is
(A) AUG
(B) GGU
(C) GGA
(D) AAA
117. AUG, the
only identified codon for methio-
nine is important as
(A) A releasing
factor for peptide chains
(B) A chain terminating
codon
(C) Recognition
site on tRNA
(D) A chain initiating codon
118. In
biosynthesis of proteins the chain
terminating codons are
(A) UAA, UAG and UGA
(B) UGG, UGU
and AGU
(C) AAU, AAG
and GAU
(D) GCG, GCA
and GCU
119. The
formation of initiation complex during protein synthesis requires a factor:
(A) IF-III
(B) EF-I
(C) EF-II
(D) IF-I
120. The
amino terminal of all polypeptide chain at the time of synthesis in E. coli is tagged
to the amino acid residue:
(A) Methionine
(B) Serine
(C) N-formyl methinine
(D) N-formal
serine
121. Initiation
of protein synthesis begins with binding of
(A) 40 S
ribosomal unit on mRNA
(B) 60S ribosomal unit
(C) Charging
of tRNA with specific amino acid
(D) Attachment
of aminoacyl tRNA on mRNA
122. Initiation
of protein synthesis requires
(A) ATP
(B) AMP
(C) GDP
(D) GTP
123. The
enzyme amino acyl tRNA synthetase
is involved in
(A)
Dissociation of discharged tRNA from 80S ribosome
(B) Charging of tRNA with specific amino acids
(C) Termination
of protein synthesis
(D)
Nucleophilic attack on esterified carboxyl group of peptidyl tRNA
124. In the
process of activation of amino acids for protein synthesis, the number of high
energy phosphate bond equivalent utilised is
(A) 0
(B) 1
(C) 2
(D) 4
125 Translation
results in a product known as
(A) Protein
(B) tRNA
(C) mRNA
(D) rRNA
126. In the
process of elongation of chain binding of amino acyl tRNA to the A site
requires
(A) A proper codon recognition
(B) GTP
(C) EF-II
(D) GDP
127. The
newly entering amino acyl tRNA into
A site requires
(A) EF-II
(B) Ribosomal
RNA
(C) mRNA
(D) EF-I
128. The
α-amino group of the new amino acyl tRNA in the A site carries out a nucleophilic
attack on the esterified carboxyl group of the peptidyl tRNA occupying the P
site. This reaction is catalysed by
(A) DNA
polymerase
(B) RNA polymerase
(C) Peptidyl transferase
(D) DNA ligase
129. The
nucleophilic attack on the esterified carboxyl group of the peptidyl-tRNA occupying
the P site and the α-amino group of the new amino acyl tRNA, the number of ATP
required by the amino acid on the charged tRNA is
(A) Zero
(B) One
(C) Two
(D) Four
130. Translocation
of the newly formed peptidyl tRNA at the A site into the empty P site involves
(A) EF-II, GTP
(B) EF-I, GTP
(C) EF-I, GDP
(D) Peptidyl
transferase, GTP
131. In
eukaryotic cells
(A) Formylated
tRNA is important for initiation of translation
(B) Cyclohexamide blocks elongation during
translation
(C) Cytosolic
ribosomes are smaller than those found in prokaryotes
(D)
Erythromycin inhibits elongation during translation
132. The
mushroom poison amanitin is an inhibitor of
(A) Protein
synthesis
(B) mRNA synthesis
(C) DNA
synthesis
(D) Adenosine
synthesis
133. Tetracylin
prevents synthesis of polypeptide by
(A) Blocking
mRNA formation from DNA
(B) Releasing peptides from mRNA-tRNA
complex
(C) Competing
with mRNA for ribosomal binding sites
(D) Preventing binding of aminoacyl tRNA
134. In
prokaryotes, chloramphenicol
(A) Causes premature release of the polypeptide chain
(B) Causes
misreading of the mRNA
(C)
Depolymerises DNA
(D) Inhibits
peptidyl transferase activity
135 Streptomycin
prevents synthesis of polypeptide by
(A) Inhibiting initiation process
(B) Releasing
premature polypeptide
(C) Inhibiting
peptidyl transferase activity
(D) Inhibiting
translocation
136. Erythromycin
acts on ribosomes and inhibit
(A) Formation
of initiation complex
(B) Binding of
aminoacyl tRNA
(C) Peptidyl
transferase activity
(D) Translocation
137. The
binding of prokaryotic DNA dependent RNA polymerase to promoter sites
of genes is inhibited by the antibiotic:
(A) Puromycin
(B) Rifamycin
(C) Terramycin
(D)
Streptomycin
138. The gene
which is transcribed during repression is
(A) Structural
(B) Regulator
(C) Promoter
(D) Operator
139 The gene
of lac operon which has constitutive expression is
(A) i
(B) c
(C) z
(D) p
140. The
minimum effective size of an operator for lac repressor binding is
(A) 5 base
pairs
(B) 10 base
pairs
(C) 15 base
pairs
(D) 17 base pairs
141 To
commence structural gene transcription the region which should be free on
lac operation is
(A) Promoter
site
(B) Operator locus
(C) Y gene
(D) A gene
142. In the
lac operon concept, a protein molecule is
(A) Operator
(B) Inducer
(C) Promoter
(D) Repressor
143. The
catabolite repression is mediated by a catabolite gene activator protein (CAP)
in conjunction with
(A) AMP
(B) GMP
(C) cAMP
(D) Cgmp
144. The enzyme DNA ligase
(A) Introduces
superhelical twists
(B) Connects the end of two DNA chains
(C) Unwinds the
double helix
(D) Synthesises
RNA primers
145. Restriction
endonucleases
(A) Cut RNA
chains at specific locations
(B) Excise
introns from hnRNA
(C) Remove
Okazaki fragments
(D) Act as defensive enzymes to protect the host bacterial
DNA from DNA of foreign organisms
146. The most
likely lethal mutation is
(A)
Substitution of adenine for cytosine
(B) Insertion of one nucleotide
(C) Deletion of
three nucleotides
(D)
Substitution of cytosine for guanine
147. In the
following partial sequence of mRNA, a mutation of the template DNA
results in a change in codon 91 to UAA. The type of
mutation is
88 89 90 91
92 93
94
GUC GAC
CAG UAG GGC
UAA CCG
(A) Missene
(B) Silent
(C) Nonsense
(D) Frame shit
148. Restriction
endonucleases recognize and
cut a certain sequence of
(A) Single
stranded DNA
(B) Double stranded DNA
(C) RNA
(D) Protein
149. Positive
control of induction is best described as a control system in which an operon
functions
(A) Unless it
is switched off by a derepressed repressor protein
(B) Only after
a repressor protein is inactivated by an inducer
(C) Only after
an inducer protein, which can be inactivated by a corepressor, switches it on
(D) Only after an inducer protein, which is activated
by an inducer, switch it on
150. Interferon
(A) Is virus
specific
(B) Is a bacterial product
(C) Is a
synthetic antiviral agent
(D) Requires expression of cellular genes
151. Repressor
binds to DNA sequence and regulate the transcription. This sequence
is called
(A) Attenuator
(B) Terminator
(C) Anti
terminator
(D) Operator
152. Okazaki
fragment is related to
(A) DNA synthesis
(B) Protein
synthesis
(C) mRNA
formation
(D) tRNA
formation
153. The
region of DNA known as TATA BOX is
the site for binding of
(A) DNA
polymerase
(B) DNA topoisomerase
(C) DNA dependent RNA polymerase
(D)
Polynucleotide phosphorylase
154. Reverse
transcriptase is capable of synthesising
(A) RNA → DNA
(B) DNA → RNA
(C) RNA → RNA
(D) DNA → DNA
155. A tetrovirus is
(A) Polio virus
(B) HIV
(C) Herpes
virus
(D) Tobacco
mosaic virus
156. Peptidyl
transferase activity is located in
(A) Elongation
factor
(B) A charged
tRNA molecule
(C) Ribosomal protein
(D) A soluble
cytosolic protein
157. Ultraviolet
light can damage a DNA strand
causing
(A) Two
adjacent purine residue to form a covalently
bounded dimer
(B) Two adjacent pyrimidine residues to form covalently
bonded dimer
(C) Disruption
of phosphodiesterase linkage
(D) Disruption
of non-covalent linkage
158. Defective
enzyme in Hurler’s syndrome is
(A)
α-L-diuronidase
(B) Iduronate sulphatase
(C) Arylsulphatase
B
(D) C-acetyl
transferase
159. Presence
of arginine can be detected by
(A) Sakaguchi
reaction
(B) Million-Nasse reaction
(C) Hopkins-Cole
reaction
(D) Gas
chromatography
160. A nitrogenous
base that does not occur
in mRNA is
(A) Cytosine
(B) Thymine
(C) Uracil
(D) All of
these
161. In
nucleotides, phosphate is attached to
sugar by
(A) Salt
bond
(B) Hydrogen
bond
(C) Ester bond
(D) Glycosidic
bond
162. Cyclic
AMP can be formed from
(A) AMP
(B) ADP
(C) ATP
(D) All of
these
163. A
substituted pyrimidine base of pharma-
cological value is
(A) 5-Iododeoxyuridine
(B) Cytisine arabinoside
(C) 5-Fluorouracil
(D) All of
these
164 The
‘transforming factor’ discovered by
Avery, McLeod and McCarty was later
found to be
(A) mRNA
(B) tRNA
(C) DNA
(D) None of
these
165. In DNA,
the complementary base of
adenine is
(A) Guanine
(B) Cytosine
(C) Uracil
(D) Thymine
166. In DNA,
three hydrogen bonds are
formed between
(A) Adenine and
guanine
(B) Adenine and thymine
(C) Guanine and
cytosine
(D) Thymine and cytosine
167. Left
handed double helix is present in
(A) Z-DNA
(B) A-DNA
(C) B-DNA
(D) None of
these
168. Nuclear
DNA is present in combination
with
(A) Histones
(B)
Non-histones
(C) Both (A) and (B)
(D) None of
these
169. Number
of guanine and cytosine residues
is equal in
(A) mRNA
(B) tRNA
(C) DNA
(D) None of
these
170. Alkalis
cannot hydrolyse
(A) mRNA
(B) tRNA
(C) rRNA
(D) DNA
171. Codons
are present in
(A) Template
strand of DNA
(B) mRNA
(C) tRNA
(D) rRNA
172. Amino
acid is attached to tRNA at
(A) 5’-End
(B) 3’-End
(C) Anticodon
(D) DHU loop
173. In
prokaryotes, the ribosomal subunits
are
(A) 30 S and
40 S
(B) 40 S
and 50 S
(C) 30 S and 50 S
(D) 40 S
and 60 S
174. Ribozymes
are
(A) Enzymes
present in ribosomes
(B) Enzymes
which combine the ribosomal subunits
(C) Enzymes
which dissociate
(D) Enzymes made up of RNA
175. The
smallest RNA among the following is
(A) rRNA
(B) hnRNA
(C) mRNA
(D) tRNA
176. The
number of adenine and thymine bases is equal in
(A) DNA
(B) mRNA
(C) tRNA
(D) rRNA
177. The
number of hydrogen bonds between adenine and thymine in DNA is
(A) One
(B) Two
(C) Three
(D) Four
178. The
complementary base of adenine in
RNA is
(A) Thymine
(B) Cystosine
(C) Guanine
(D) Uracil
179. Extranuclear
DNA is present in
(A) Ribosomes
(B) Endoplasmic
reticulum
(C) Lysosomes
(D) Mitochondria
180. Mitochondrial
DNA is present in
(A) Bacteria
(B) Viruses
(C) Eukaryotes
(D) All of
these
181. Ribothymidine
is present in
(A) DNA
(B) tRNA
(C) rRNA
(D) hnRNA
182. Ten base
pairs are present in one turn of the helix in
(A) A-DNA
(B) B-DNA
(C) C-DNA
(D) Z-DNA
183. Transfer
RNA transfers
(A) Information
from DNA to ribosomes
(B) Information
from mRNA to cytosol
(C) Amino acids from cytosol to ribosomes
(D) Proteins
from ribosomes to cytosol
184. Ceramidase
is deficient in
(A) Fabry’s
disease
(B) Farber’s disease
(C) Krabbe’s
disease
(D) Tay-Sachs
disease
185. Ceramide
is present in all of the following except
(A) Plasmalogens
(B)
Cerebrosides
(C) Sulphatides
(D)
Sphingomyelin
186. Nucleotides
required for the synthesis of nucleic acids can be obtained from
(A) Dietary
nucleic acids and nucleotides
(B) De novo
synthesis
(C) Salvage of
pre-existing bases and nucleosides
(D) De novo synthesis and salvage
187. De novo
synthesis of purine nucleotide occurs in
(A) Mitochondria
(B) Cytosol
(C) Microsmes
(D) Ribosomes
188. The
nitrogen atoms for de novo synthesis of purine nucleotides are provided by
(A) Aspartate
and glutamate
(B) Aspartate
and glycine
(C) Aspartate, glutamine and glycine
(D) Aspartate, glutamate
and glycine
189 For de
novo synthesis of purine nucleotides, glycine provides
(A) One
nitrogen atom
(B) One
nitrogen and one carbon atom
(C) Two carbon
atoms
(D) One nitrogen and two carbon atoms
190. For de
novo synthesis of purine nucleotides, aspartate provides
(A) Nitrogen 1
(B) Nitrogen 3
(C) Nitrogen 7
(D) Nitrogen 9
191. In the
purine nucleus, carbon 6 is contributed by
(A) Glycine
(B) CO2
(C) Aspartate
(D) Glutamine
192. 5-Phosphoribosyl-1-pyrophosphate
is required for the synthesis of
(A) Purine
nucleotides
(B) Pyrimidine
nucleotides
(C) Both (A) and (B)
(D) None of
these
193. Inosine
monophophate is an intermediate during the de novo synthesis of
(A) AMP and GMP
(B) CMP and UMP
(C) CMP and TMP
(D) All of
these
194. Xanthosine monophosphate
is an intermediate during de novo
synthesis of
(A) TMP
(B) CMP
(C) AMP
(D) GMP
195. In the
pathway of de novo synthesis of purine nucleotides, all the following are
allosteric enzymes except
(A) PRPP glutamyl
amido transferase
(B)
Adenylosuccinate synthetase
(C) IMP
dehydrogenase
(D) Adenylosuccinase
196. All of
the following enzymes are unique
to purine nucleotide synthesis except
(A) PRPP synthetase
(B) PRPP
glutamyl amido transferase
(C) Adenylosuccinate
synthetase
(D) IMP
dehydrogenase
197. PRPP
synthetase is allosterically inhibited
by
(A) AMP
(B) ADP
(C) GMP
(D) All of these
198. An
allosteric inhibitor of PRPP glutamyl amido transferase is
(A) AMP
(B) ADP
(C) GMP
(D) All of
these
199. An
allosteric inhibitor of adenylosuccinate synthetase is
(A) AMP
(B) ADP
(C) GMP
(D) GDP
200. An
allosteric inhibitor of IMP dehydrogenase is
(A) AMP
(B) ADP
(C) GMP
(D) GDP
201. GMP is
an allosteric inhibitor of all the
following except
(A) PRPP
synthetase
(B) PRPP
glutamyl amido synthetase
(C) IMP
dehydrogenase
(D) Adenylosuccinate synthetase
202. AMP is
an allosteric inhibitor of
(A) PRPP
synthetase
(B)
Adenylosucciante synthetase
(C) Both (A) and (B)
(D) None of
these
203. The
first reaction unique to purine nucleotide synthesis is catalysed by
(A) PRPP
synthetase
(B) PRPP glutamyl amido transferase
(C)
Phosphoribosyl glycinamide synthetase
(D) Formyl
transferase
204. Free
purine bases which can be salvaged
are
(A) Adenine and
guanine
(B) Adenine and hypoxanthine
(C) Guanine and
hypoxanthine
(D) Adenine, guanine and hypoxanthine
205. The
enzyme required for salvage of free
purine bases is
(A) Adenine
phosphoribosyl transferase
(B) Hypoxanthine guanine phosphoribosyl transferase
(C) Both (A) and (B)
(D) None of
these
206. Deoxycytidine
kinase can salvage
(A) Adenosine
(B) Adenosine
and deoxyadenosine
(C) Adenosine
and guanosine
(D) Adenine and adenosine
207. Adenosine
kinase can salvage
(A) Adenosine
(B) Adenosine and deoxyadenosine
(C) Adenosine
and guanosine
(D) Adenine and
adenosine
208. Salvage
of purine bases is regulated by
(A) Adenosine
phosphoribosyl transferase
(B)
Hypoxanthine guanine phosphoribosyl transferase
(C) Availability of PRPP
(D) None of
these
209. The
available PRPP is used preferentially
for
(A) De novo
synthesis of purine nucleotides
(B) De novo
synthesis of pyrimidine nucleotides
(C) Salvage of purine bases
(D) Salvage of
pyrimidine bases
210. The end
product of purine catabolism in man is
(A) Inosine
(B)
Hypoxanthine
(C) Xanthine
(D) Uric acid
211. The
enzyme common to catabolism of all the purines is
(A) Adenosine
deaminase
(B) Purine nucleoside phosphorylase
(C) Guanase
(D) None of
these
212. Uric
acid is the end product of purine as well as protein catabolism in
(A) Man
(B) Fish
(C) Birds
(D) None of
these
213. Daily
uric acid excretion in adult men is
(A) 2-6 mg
(B) 20-40
mg
(C) 150-250
mg
(D) 40-600 mg
214. Dietary
purines are catabolised in
(A) Liver
(B) Kidneys
(C) Intesitnal mucosa
(D) All of
these
215. De novo
synthesis of pyrimidine nucleotides occurs in
(A)
Mitochondria
(B) Cytosol
(C) Microsomes
(D) Ribosomes
216. An
enzyme common to de novo synthesis of pyrimidine nucleotides and urea is
(A) Urease
(B) Carbamoyl phosphate synthetase
(C) Aspartate
transcarbamoylase
(D)
Argininosuccinase
217. The
nitrogen atoms of pyrimidine nucleus are provided by
(A) Glutamate
(B) Glutamate
and aspartate
(C) Glutamine
(D) Glutamine and aspartate
218. The
carbon atoms of pyrimidine nucleus are provided by
(A) Glycine and
aspartate
(B) CO2 and aspartate
(C) CO2 and
glutamate
(D) CO2
and glutamine
219. Nitrogen
at position 1 of pyrimidine nucleus comes from
(A) Glutamine
(B) Glutamate
(C) Glycine
(D) Aspartate
220. Nitrogen
at position 3 of pyrimidine nucleus comes from
(A) Glutamine
(B) Glutamate
(C) Glycine
(D) Aspartate
221. The
carbon atom at position 2 of pyrimidine nucleus is contributed by
(A) CO2
(B) Glycine
(C) Aspartate
(D) Glutamine
222. Aspartate
contributes the following carbon atoms of the pyrimidine nucelus:
(A) C2
and C4
(B) C5
and C6
(C) C2,
C4 and C6
(D) C4, C5 and C6
223. The first
pyrimidine nucleotide to be formed in de novo synthesis pathway is
(A) UMP
(B) CMP
(C) CTP
(D) TMP
224. Conversion
of uridine diphosphate into deoxyuridine diphosphate requires all
the following except
(A)
Ribonucleotide reductase
(B) Thioredoxin
(C) Tetrahydrobiopterin
(D) NADPH
225. Amethopterin
and aminopterin decrease the synthesis of
(A) TMP
(B) UMP
(C) CMP
(D) All of
these
226. For
synthesis of CTP and UTP, the amino
group comes from
(A) Amide group
of Asparagine
(B) Amide group of glutamine
(C) α-Amino
group of glutamine
(D) α-Amino
group of glutamate
227. CTP
synthetase forms CTP from
(A) CDP and
inorganic phosphate
(B) CDP and ATP
(C) UTP and glutamine
(D) UTP and
glutamate
228. For the
synthesis of TMP from dump, a
coenzyme is required which is
(A) N10-
Formyl tetrahydrofolate
(B) N5- Methyl
tetrahydrofolate
(C) N5, N10- Methylene
tetrahydrofolate
(D) N5-
Formimino tetrahydrofolate
229. All the
enzymes required for de novo synthesis of pyrimidine nucleotides are
cytosolic except
(A) Carbamoyl
phosphate synthetase
(B) Aspartate
transcarbamoylase
(C)
Dihydro-orotase
(D) Dihydro-orotate dehydrogenase
230. During
de novo synthesis of pyrimidine nucleotides, the first ring compound to be
formed is
(A) Carbamoyl
aspartic acid
(B) Dihydro-orotic acid
(C) Orotic acid
(D) Orotidine
monophosphate
231. Tetrahydrofolate
is required as a coenzyme for the synthesis of
(A) UMP
(B) CMP
(C) TMP
(D) All of
these
232. All of
the following statements about thioredoxin reductase are true except:
(A) It requires NADH as a coenzyme
(B) Its substrates are ADP, GDP, CDP and
UDP
(C) It is
activated by ATP
(D) It is
inhibited by dADP
233. De novo
synthesis of pyrimidine nucleotides is regulated by
(A) Carbamoyl
phosphate synthetase
(B) Aspartate
transcarbamoylase
(C) Both (A) and (B)
(D) None of
these
234. Cytosolic
carbamoyl phosphate synthetase is inhibited by
(A) UTP
(B) CTP
(C) PRPP
(D) TMP
235. Cytosolic
carbamoyl phosphate synthetase is activated by
(A) Glutamine
(B) PRPP
(C) ATP
(D) Aspartate
236. Aspartate
transcarbamoylase is inhibited
by
(A) CTP
(B) PRPP
(C) ATP
(D) TMP
237. The following
cannot be salvaged in human beings:
(A) Cytidine
(B)
Deoxycytidine
(C) Cytosine
(D) Thymidine
238. β -Aminoisobytyrate
is formed from catabolism of
(A) Cytosine
(B) Uracil
(C) Thymine
(D) Xanthine
239. Free
ammonia is liberated during the
catabolism of
(A) Cytosine
(B) Uracil
(C) Thymine
(D) All of these
240. β
-Alanine is formed from catabolism of
(A) Thymine
(B) Thymine and
cytosine
(C) Thymine and
uracil
(D) Cytosine and uracil
241. The
following coenzyme is required for
catabolism of pyrimidine bases:
(A) NADH
(B) NADPH
(C) FADH2
(D) None of
these
242. Inheritance
of primary gout is
(A) Autosomal
recessive
(B) Autosomal
dominant
(C) X-linked recessive
(D) X-linked
dominant
243. The
following abnormality in PRPP synthetase can cause primary gout:
(A) High Vmax
(B) Low Km
(C) Resistance
to allosteric inihbition.
(D) All of these
244. All the
following statements about primary gout are true except
(A) Its
inheritance is X-linked recessive
(B) It can be due to increased activity
of PRPP synthetase
(C) It can be due to increased activity of hypoxanthine
guanine phosphoribosyl transferase
(D) De novo
synthesis of purines is increased in it
245. All of
the following statements about uric acid are true except
(A) It is a
catabolite of purines
(B) It is excreted by the kidneys
(C) It is undissociated at pH above 5.8
(D) It is less
soluble than sodium urate
246. In
inherited deficiency of hypoxanthine guanine phosphoribosyl transferase
(A) De novo
synthesis of purine nucleotides is decreased
(B) Salvage of purines is decreased
(C) Salvage of
purines is increased
(D) Synthesis
of uric acid is decreased
247. All of
the following statements about uric acid are true except
(A) It can be formed from allantoin
(B) Formation
of uric acid stones in kidneys can be decreased by alkalinisation of urine
(C) Uric acid
begins to dissociate at pH above 5.8
(D) It is
present in plasma mainly as monosodiumurate
248. All of
the following statements about primary gout are true except
(A) Uric acid
stones may be formed in kidneys
(B) Arthritis
of small joints occurs commonly
(C) Urinary excretion of uric acid is decreased
(D) It occurs
predominantly in males
249. All of
the following statements about
allopurinol are true except
(A) It is a structural analogue of uric acid
(B) It can prevent uric acid stones in
the kidneys
(C) It
increases the urinary excretion of xanthine and hypoxanthine
(D) It is a
competitive inhibitor of xanthine oxidase
250. Orotic
aciduria can be controlled by
(A) Oral
administration of orotic acid
(B) Decreasing the dietary intake of
orotic acid
(C) Decreasing
the dietary intake of pyrimidines
(D) Oral administration of uridine
251. All of
the following occur in orotic aciduria
except
(A) Increased synthesis of pyrimidine nucleotides
(B) Increased
excretion of orotic acid in urine
(C) Decreased
synthesis of cytidine triphosphate
(D) Retardation
of growth
252. Inherited
deficiency of adenosine deaminase causes
(A)
Hyperuricaemia and gout
(B) Mental
retardation
(C) Immunodeficiency
(D) Dwarfism
253. Complete
absence of hypoxanthine guanine phospharibosyl transferase causes
(A) Primary
gout
(B)
Immunodeficiency
(C) Uric acid
stones
(D) Lesh-Nyhan syndrome
254. Increased
urinary excretion of orotic acid can occur in deficiency of
(A) Orotate
phosphoribosyl transferase (B) OMP
decarboxylase
(C)
Mitochondrial ornithine transcarbamoylase
(D) Any of the above
255. All of
the following can occur in LeschNyhan syndrome except
(A) Gouty
arthritis
(B) Uric acid
stones
(C) Retarted growth
(D)
Self-mutiliating behaviour
256. Inherited
deficiency of purine nucleoside
phosphorylase causes
(A) Dwarfism
(B) Mental
retardation
(C) Immunodeficiency
(D) Gout
257. Deoxyribonucleotides
are formed by
reduction of
(A)
Ribonucleosides
(B)
Ribonucleoside monophosphates
(C) Ribonucleoside diphosphates
(D)
Ribonucleoside triphosphates
258. An
alternate substrate for orotate
phosphoribosyl transferase is
(A) Allopurinol
(B) Xanthine
(C)
Hypoxanthine
(D) Adenine
259. Mammals
other than higher primates do
not suffer from gout because they
(A) Lack
xanthine oxidase
(B) Lack adenosine deaminase
(C) Lack purine
nucleoside phosphorylase
(D) Possess uricase
260. Hypouricaemia
can occur in
(A) Xanthine oxidase deficiency
(B) Psoriasis
(C) Leukaemia
(D) None of
these
261. Synthesis
of DNA is also known as
(A) Duplication
(B) Replication
(C)
Transcription
(D) Translation
262. Replication
of DNA is
(A)
Conservative
(B) Semi-conservative
(C)
Non-conservative
(D) None of
these
263. Direction
of DNA synthesis is
(A) 5’ → 3’
(B) 3’ → 5’
(C) Both
(A) and (B)
(D) None of
these
264. Formation
of RNA primer:
(A) Precedes replication
(B) Follows
replication
(C) Precedes
transcription
(D) Follows
transcription
265. Okazaki
pieces are made up of
(A) RNA
(B) DNA
(C) RNA and DNA
(D) RNA and
proteins
266. Okazaki
pieces are formed during the
synthesis of
(A) mRNA
(B) tRNA
(C) rRNA
(D) DNA
267. After
formation of replication fork
(A) Both the
new strands are synthesized discontinuously
(B) One strand is synthesized continuously and the other discontinuously
(C) Both the
new strands are synthesized continuously
(D) RNA primer
is required only for the synthesis of
one new strand
268. An
Okazaki fragment contains about
(A) 10
Nucleotides
(B) 100
Nucleotides
(C) 1,000 Nucleotides
(D) 10,000
Nucleotides
269. RNA
primer is formed by the enzyme:
(A)
Ribonuclease
(B) Primase
(C) DNA
polymerase I
(D) DNA
polymerase III
270. In RNA,
the complementary base of ade-
nine is
(A) Cytosine
(B) Guanine
(C) Thymine
(D) Uracil
271. During
replication, the template DNA is
unwound
(A) At one of the
ends
(B) At both the
ends
(C) At multiple sites
(D) Nowhere
272. During
replication, unwinding of double
helix is initiated by
(A) DNAA
protein
(B) DnaB protein
(C) DNAC
protein
(D) Rep protein
273. For
unwinding of double helical DNA,
(A) Energy is provided by ATP
(B) Energy is
provided by GTP
(C) Energy can
be provided by either ATP or GTP
(D) No energy
is required
274. Helicase
and DNAB protein cause
(A) Rewinding
of DNA and require ATP as a source of energy
(B) Rewinding
of DNA but do not require any source of energy
(C) Unwinding of DNA and require ATP as a source
of energy
(D) Unwinding
of DNA but do not require any source of energy
275. The
unwound strands of DNA are held
apart by
(A) Single strand binding protein
(B) Double strand binding protein
(C) Rep protein
(D) DNAA
protein
276. Deoxyribonucleotides
are added to RNA
primer by
(A) DNA
polymerase I
(B) DNA
polymerase II
(C) DNA polymerase III holoenzyme
(D) All of
these
277. Ribonucleotides
of RNA primer are replaced by deoxyribonucleotides by the
enzyme:
(A) DNA polymerase I
(B) DNA
polymerase II
(C) DNA
polymerase III holoenzyme
(D) All of
these
278. DNA
fragments are sealed by
(A) DNA
polymerase II
(B) DNA ligase
(C) DNA gyrase
(D) DNA topoisomerase
II
279. Negative
supercoils are introduced in DNA
by
(A) Helicase
(B) DNA ligase
(C) DNA gyrase
(D) DNA
polymerase III holoenzyme
280. Reverse
transcriptase activity is present
in the eukaryotic:
(A) DNA
polymerase α
(B) DNA
polymerase γ
(C) Telomerase
(D) DNA
polymerase II
281. DNA
polymerase III holoenzyme possesses
(A) Polymerase
activity
(B) 3’→5’
Exonuclease activity
(C) 5’→3’
Exonuclease and polymerase activities
(D) 3’→5’ Exonuclease and polymerase activities
282. DNA
polymerase I possesses
(A) Polymerase
activity
(B) 3’→5’
Exonuclease activity
(C) 5’→3’
Exonuclease activity
(D) All of these
283. 3’→5’
Exonuclease activity of DNA
polymerase I
(A) Removes
ribonucleotides
(B) Adds
deoxyribonucleotides
(C) Corrects errors in replication
(D) Hydrolyses
DNA into mononucleotides
284. All of
the following statements about
RNA-dependent DNA polymerase are true
except:
(A) It
synthesizes DNA using RNA as a template
(B) It is also
known as reverse transcriptase
(C) It
synthesizes DNA in 5’→3’ direction
(D) It is present in all the viruses
285. Reverse
transcriptase catalyses
(A) Synthesis
of RNA
(B) Breakdown
of RNA
(C) Synthesis of DNA
(D) Breakdown
of DNA
286. DNA A
protein can bind only to
(A) Positively
supercoiled DNA
(B) Negatively supercoiled DNA
(C) Both (A)
and (B)
(D) None of
these
287. DNA
topoisomerase I of E. coli catalyses
(A) Relaxation of negatively supercoiled DNA
(B) Relaxation
of positively supercoiled DNA
(C) Conversion
of negatively supercoiled DNA into positively supercoiled DNA
(D) Conversion
of double helix into supercoiled DNA
288. In
mammalian cell cycle, synthesis of DNA
occurs during
(A) S phase
(B) G1
phase
(C) Mitotic
Phase
(D) G2
phase
289. Melting
temperature of DNA is the tempera-
ture at which
(A) Solid DNA
becomes liquid
(B) Liquid DNA
evaporates
(C) DNA changes
from double helix into supercoiled DNA
(D) Native double helical DNA is denatured
290. Melting
temperature of DNA is increased
by its
(A) A and T
content
(B) G and C content
(C) Sugar
content
(D) Phosphate
content
291. Buoynat
density of DNA is increased by
its
(A) A and T
content
(B) G and C content
(C) Sugar
content
(D) None of
these
292. Relative
proportions of G and C versus A and T in DNA can be determined by its
(A) Melting
temperature
(B) Buoyant
density
(C) Both (A) and (B)
(D) None of
these
293. Some DNA
is present in mitochondria of
(A) Prokaryotes
(B) Eukaryotes
(C) Both (A)
and (B)
(D) None of
these
294. Satellite
DNA contains
(A) Highly repetitive sequences
(B) Moderately
repetitive sequences
(C)
Non-repetitive sequences
(D) DNA-RNA
hybrids
295. Synthesis
of RNA and a DNA template is known as
(A) Replication
(B) Translation
(C) Transcription
(D) Mutation
296. Direction
of RNA synthesis is
(A) 5′ → 3’
(B) 3′ → 5’
(C) Both
(A) and (B)
(D) None of
these
297. DNA-dependent
RNA polymerase is a
(A) Monomer
(B) Dimer
(C) Trimer
(D) Tetramer
298. DNA-dependent
RNA polymerase requires the following for its catalytic activity:
(A) Mg++
(B) Mn++
(C) Both (A) and (B)
(D) None of
these
299. The
initiation site for transcription is
recognized by
(A) α−Subunit
of DNA-dependent RNA polymerase
(B) β−Subunit of DNA-dependent RNA
polymerase
(C) Sigma factor
(D) Rho factor
300. The
termination site for transcription is recognized by
(A) α−Subunit
of DNA-dependent RNA polymerase
(B) β−Subunit
of DNA-dependent RNA polymerase
(C) Sigma
factor
(D) Rho factor
301. Mammalian
RNA polymerase I synthesises
(A) mRNA
(B) rRNA
(C) tRNA
(D) hnRNA
302. Mammalian
RNA polymerase III synthesises
(A) rRNA
(B) mRNA
(C) tRNA
(D) hnRNA
303. In
mammals, synthesis of mRNA is
catalysed by
(A) RNA
polymerase I
(B) RNA polymerase II
(C) RNA
polymerase III
(D) RNA polymerase
IV
304. Heterogeneous
nuclear RNA is the precursor of
(A) mRNA
(B) rRNA
(C) tRNA
(D) None of
these
305. Post-transcriptional
modification of hnRNA involves all of the following except
(A) Addition of 7-methylguanosine triphosphate cap
(B) Addition of
polyadenylate tail
(C) Insertion
of nucleotides
(D) Deletion of
introns
306. Newly
synthesized tRNA undergoes post-transcriptional modifications which include
all the following except
(A) Reduction
in size
(B) Methylation
of some bases
(C) Formation of pseudouridine
(D) Addition of
C-C-A terminus at 5’ end
307. Post-transcriptional
modification does not occur in
(A) Eukaryotic
tRNA
(B) Prokaryotic
tRNA
(C) Eukaryotic
hnRNA
(D) Prokaryotic mRNA
308. A
consensus sequence on DNA, called TATA box, is the site for attachment of
(A)
RNA-dependent DNA polymerase
(B) DNA-dependent RNA polymerase
(C)
DNA-dependent DNA polymerase
(D) DNA
topoisomerase II
309. Polyadenylate
tail is not present in mRNA
synthesising
(A) Globin
(B) Histone
(C) Apoferritin
(D) Growth
hormone
310. Introns
are present in DNA of
(A) Viruses
(B) Bacteria
(C) Man
(D) All of
these
311. A
mammalian DNA polymerase among
the following is
(A) DNA polymerase α
(B) DNA
polymerase I
(C) DNA
polymerase II
(D) DNA
polymerase IV
312. Mammalian
DNA polymerase γ is located
in
(A) Nucleus
(B) Nucleolus
(C) Mitochondria
(D) Cytosol
313. Replication
of nuclear DNA in mammals
is catalysed by
(A) DNA polymerase α
(B) DNA polymerase β
(C) DNA
polymerase γ
(D) DNA
polymerase III
314. Primase
activity is present in
(A) DNA
polymerase II
(B) DNA polymerase α
(C) DNA
polymerase β
(D) DNA
polymerase δ
315. The mammalian
DNA polymerase involved in error
correction is
(A) DNA
polymerase α
(B) DNA polymerase β
(C) DNA
polymerase γ
(D) DNA
polymeraseδ
316. Novobicin
inhibits the synthesis of
(A) DNA
(B) mRNA
(C) tRNA
(D) rRNA
317. Ciprofloxacin
inhibits the synthesis of
(A) DNA
(B) mRNA
(C) tRNA
(D) rRNA
318. Ciprofloxacin
inhibits
(A) DNA
topisomerase II
(B) DNA
polymerase I
(C) DNA
polymerase III
(D) DNA gyrase
319. Rifampicin
inhibits
(A) Unwinding
of DNA
(B) Initiation of replication
(C) Initiation
of translation
(D) Initiation of transcription
320. Actinomycin
D binds to
(A) Double stranded DNA
(B) Single
stranded DNA
(C) Single
stranded RNA
(D) DNA-RNA
hybrid
321. DNA
contains some palindromic sequences
which
(A) Mark the
site for the formation of replication forks
(B) Direct DNA
polymerase to turn back to replicate the other strand
(C) Are recognized by restriction enzymes
(D) Are found
only in bacterial DNA
322. Introns
in genes
(A) Encode the
amino acids which are removed during post-translational modification
(B) Encode
signal sequences which are removed before secretion of the proteins
(C) Are the non-coding sequences which are not translated
(D) Are the
sequences that intervene between two genes
323. All of
the following statements about post-transcriptional processing of tRNA
are true except
(A) Introns of
some tRNA precursors are removed
(B) CCA is
added at 3′ end
(C) 7-Methylguanosine triphosphate cap is added
at 5′ end
(D) Some bases
are methylated
324. α-Amanitin
inhibits
(A) DNA polymerase
II of prokaryotes
(B) DNA
polymerase α of eukaryotes
(C) RNA polymerase II of eukaryotes
(D)
RNA-dependent DNA polymerase
325. Ciprofloxacin
inhibits the synthesis of
(A) DNA in prokaryotes
(B) DNA in
prokaryotes and eukaryotes
(C) RNA in prokaryotes
(D) RNA in
prokaryotes and eukaryotes
326. All of
the following statements about bacterial promoters are true except
(A) They are
smaller than eukaryotic promoters
(B) They have
two consensus sequences upstream from the transcription star site
(C) TATA box is
the site for attachment of RNA polymerase
(D) TATA box has a high melting temperature
327. All of
the following statements about
eukaryotic promoters are true except
(A) They may be located upstream or down stream from
the structural gene
(B) They have
two consensus sequences
(C) One
consensus sequence binds RNA polymerase
(D) Mutations
in promoter region can decrease the efficiency of transcription of the
structural gene
328. In
sanger’s method of DNA sequence determination, DNA synthesis is stopped
by using
(A) 1′, 2′- Dideoxyribonucleoside triphosphates
(B) 2′, 3′-
Dideoxyribonucleoside triphosphates
(C) 2′, 4′-
Dideoxyribonucleoside triphosphates
(D) 2′, 5′
- Dideoxyribonucleoside triphosphates
329. tRNA
genes have
(A) Upstream
promoters
(B) Downstream promoters
(C) Intragenic promoters
(D) No
promoters
330. All of
the following statements about
tRNA are true except
(A) It is
synthesized as a large precursor
(B) It is
processed in the nucelolus
(C) It has no
codons or anticodons
(D) Genes for rRNA are present in single copies
331. Anticodons
are present on
(A) Coding
strand of DNA
(B) mRNA
(C) tRNA
(D) rRNA
332. Codons
are present on
(A) Non-coding
strand of DNA
(B) hnRNA
(C) tRNA
(D) None of
these
333. Nonsense
codons are present on
(A) mRNA
(B) tRNA
(C) rRNA
(D) None of
these
334. Genetic
code is said to be degenerate because
(A) It can
undergo mutations
(B) A large
proportion of DNA is non-coding
(C) One codon
can code for more than one amino acids
(D) More than one codons can code for the same amino
acids
335. All the
following statements about genetic
code are correct except
(A) It is
degenerate
(B) It is
unambigous
(C) It is
nearly universal
(D) It is overlapping
336. All of
the following statements about
nonsense codons are true except
(A) They do not
code for amino acids
(B) They act as chain termination
signals
(C) They
are identical in
nuclear and mitochondrial DNA
(D) They have
no complementary anticodons
337. A
polycistronic mRNA can be seen in
(A) Prokaryotes
(B) Eukaryotes
(C)
Mitochondria
(D) All of
these
338. Non-coding
sequence are present in the
genes of
(A) Bacteria
(B) Viruses
(C) Eukaryotes
(D) All of
these
339. Non-coding
sequences in a gene are known as
(A) Cistrons
(B) Nonsense
codons
(C) Introns
(D) Exons
340. Splice
sites are present in
(A) Prokaryotic
mRNA
(B) Eukaryotic
mRNA
(C) Eukaryotic hnRNA
(D) All of
these
341. The
common features of introns include
all the following except
(A) The base
sequence begins with GU
(B) The base sequence ends with AG
(C) The terminal AG sequence is preceded by a purine
rich tract of ten nucleotides
(D) An
adenosine residue in branch site participates in splicing
342. A splice
some contains all the following except
(A) hnRNA
(B) snRNAs
(C) Some
proteins
(D) Ribosome
343. Self-splicing
can occur in
(A) Some precursors of rRNA
(B) Some
precursors of tRNA
(C) hnRNA
(D) None of
these
344. Pribnow
box is present in
(A) Prokaryotic promoters
(B) Eukaryotic
promoters
(C) Both (A)
and (B)
(D) None of
these
345. Hogness
box is present in
(A) Prokaryotic
promoters
(B) Eukaryotic promoters
(C) Both (A)
and (B)
(D) None of
these
346. CAAT box
is present in
(A) Prokaryotic
promoters 10 bp upstream of transcription start site
(B) Prokaryotic
promoters 35 bp upstream of transcription start site
(C) Eukaryotic
promoters 25 bp upstream of transcription start site
(D) Eukaryotic promoters 70-80 bp upstream of transcription
start site
347. Eukaryotic
promoters contain
(A) TATA box
25bp upstream of transcription start site
(B) CAAT box
70-80 bp upstream of transcription start site
(C) Both (A) and (B)
(D) None of
these
348. All the
following statements about tRNA
are correct except
(A) A given tRNA
can be charged with only one particular amino acid
(B) The amino acid is recognized by the anticodon
of tRNA
(C) The amino
acid is attached to end of tRNA
(D) The
anticodon of tRNA finds the complementary codon on mRNA
349. All the
following statements about charging of tRNA are correct except
(A) It is
catalysed by amino acyl tRNA synthetase
(B) ATP is converted into ADP and Pi in this reaction
(C) The enzyme
recognizes the tRNA and the amino acid
(D) There is a
separate enzyme for each tRNA
350. All the
following statements about recognition of a codon on mRNA by an
anticodon on tRNA are correct except
(A) The
recognition of the third base of the codon is not very precise
(B) Imprecise
recognition of the third base results in wobble
(C) Wobble is
par tly responsible for the degeneracy of the genetic code
(D) Wobble results in incorporation of incorrect amino
acids in the protein
351. The
first amino acyl tRNA which initiates
translation in eukaryotes is
(A) Mehtionyl tRNA
(B) Formylmethionyl tRNA
(C) Tyrosinyl
tRNA
(D) Alanyl tRNA
352. The
first amino acyl tRNA which initiates
translation in prokaryotes is
(A) Mehtionyl
tRNA
(B) Formylmethionyl tRNA
(C) Tyrosinyl
tRNA
(D) Alanyl tRNA
353. In
eukaryotes, the 40 S pre-initiation complex contains all the following
initiation factors except
(A) eIF-1A
(B) eIF-2
(C) eIF-3
(D) eIF-4
354. Eukaryotic
initiation factors 4A, 4B and 4F bind to
(A) 40 S ribosomal subunit
(B) 60 S ribosomal subunit
(C) mRNA
(D) Amino
acyl tRNA
355. The
codon which serves as translation
start signal is
(A) AUG
(B) UAG
(C) UGA
(D) UAA
356. The
first amino acyl tRNA approaches 40 S ribosomal subunit in association with
(A) eIF-1A and
GTP
(B) eIF-2 and GTP
(C) eIF-2C and
GTP
(D) eIF-3 and
GTP
357. eIF-1A
and eIF-3 are required
(A) For binding
of amino acyl tRNA to 40 S ribosomal subunit
(B) For binding
of mRNA to 40 S ribosomal subunit
(C) For binding
of 60 S subunit to 40 S subunit
(D) To prevent binding of 60 S subunit to 40 S subunit
358. eIF-4 A
possesses
(A) ATPase activity
(B) GTPase
activity
(C) Helicase
activity
(D) None of
these
359. eIF-4 B
(A) Binds to 3’
chain initiation codon on mRNA
(B) Binds to 3’
end of mRNA
(C) Binds to 5’
end of mRNA
(D) Unwinds mRNA near its 5’ end
360. Peptidyl
transferase activity is present in
(A) 40 S
ribosomal subunit
(B) 60 S ribosomal subunit
(C) eEF-2
(D) Amino
acyl tRNA
361. After
formation of a peptide bond, mRNA is translocated along the ribosome by
(A) eEF-1 and
GTP
(B) eEF-2 and GTP
(C) Peptidyl
transferase and GTP
(D) Peptidyl
transferase and ATP
362. Binding
of formylmehtionyl tRNA to 30 S ribosomal subunit of prokaryotes is
inhibited by
(A) Streptomycin
(B)
Chloramphenicol
(C)
Erythromycin
(D) Mitomycin
363. Tetracyclines
inhibit binding of amino acyl
tRNAs to
(A) 30 S ribosomal subunits
(B) 40 S
ribosomal subunits
(C) 50 S
ribosomal subunits
(D) 60 S
ribosomal subunits
364. Peptidyl
transferase activity of 50 S
ribosomal subunits is inhibited by
(A) Rifampicin
(B)
Cycloheximide
(C) Chloramphenicol
(D)
Erythromycin
365. Erythromycin
binds to 50 S ribosomal sub
unit and
(A) Inhibits
binding of amino acyl tRNA
(B) Inhibits
Peptidyl transferase activity
(C) Inhibits translocation
(D) Causes
premature chain termination
366. Puromycin
causes premature chain
termination in
(A) Prokaryotes
(B) Eukaryotes
(C) Both (A) and (B)
(D) None of
these
367. Diphtheria
toxin inhibits
(A) Prokaryotic
EF-1
(B) Prokaryotic
EF-2
(C) Eukaryotic
EF-1
(D) Eukaryotic EF-2
368. The
proteins destined to be transported out of the cell have all the following
features
except
(A) They
possess a signal sequence
(B) Ribosomes
synthesizing them are bound to endoplasmic reticulum
(C) After synthesis,
they are delivered into Golgi apparatus
(D) They are tagged with ubiquitin
369. SRP
receptors involved in protein export
are present on
(A) Ribosomes
(B) Endoplasmic reticulum
(C) Golgi
appartus
(D) Cell
membrane
370. The
signal sequence of proteins is cleaved
off
(A) On the
ribosomes immediately after synthesis
(B) In the endoplasmic reticulum
(C) During
processing in Golgi apparatus
(D) During
passage through the cell membrane
371. The
half-life of a protein depends upon its
(A) Signal
sequence
(B) N-terminus amino acid
(C) C-terminus
amino acid
(D) Prosthetic
group
372. Besides
structural genes that encode proteins, DNA contains some regulatory
sequences which are known as
(A) Operons
(B) Cistrons
(C) Cis-acting elements
(D)
Trans-acting factors
373. Inducers
and repressors are
(A) Enhancer
and silencer elements respectively
(B) Trans-acting factors
(C) Cis-acting
elements
(D) Regulatory
proteins
374. cis-acting
elements include
(A) Steroid
hormones
(B) Calcitriol
(C) Histones
(D) Silencers
375. Silencer
elements
(A) Are
trans-acting factors
(B) Are present
between promoters and the structural genes
(C) Decrease the expression of some structural genes
(D) Encode
specific repressor proteins
376. trans-acting
factors include
(A) Promoters
(B) Repressors
(C) Enhancers
(D) Silencers
377. Enhancer
elements have all the following
features except
(A) They
increase gene expression through a promoter
(B) Each enhancer activates a specific promoter
(C) They may be
located far away from the promoter
(D) They may be
upstream or downstream from the promoter
378. Amplification
of dihydrofolate reductase
gene may be brought about by
(A) High
concentrations of folic acid
(B) Deficiency
of folic acid
(C) Low
concentration of thymidylate
(D) Amethopterin
379. Proteins
which interact with DNA and affect the rate of transcription possess the
following structural motif:
(A)
Helix-turn-helix motif
(B) Zinc finger
motif
(C) Leucine
zipper motif
(D) All of these
380. Lac
operon is a cluster of genes present in
(A) Human
beings
(B) E. coli
(C) Lambda
phage
(D) All of
these
381. Lac
operon is a cluster of
(A) Three
structural genes
(B) Three
structural genes and their promoter
(C) A
regulatory gene, an operator and a promoter
(D) A regulatory gene, an operator, a promoter and
three structural genes
382. The
regulatory i gene of lac operon
(A) Is
inhibited by lacotse
(B) Is
inhibited by its own product, the repressor protein
(C) Forms a
regulatory protein which increases the expression of downstream structural
genes
(D) Is constitutively expressed
383. RNA polymerase
holoenzyme binds to lac operon at the following site:
(A) i gene
(B) z gene
(C) Operator
locus
(D) Promoter region
384. Trancription
of z, y and a genes of lac operon is prevented by
(A) Lactose
(B)
Allo-lactose
(C) Repressor
(D) cAMP
385. Transcription
of structural genes of lac operon is prevented by binding of the
repressor tetramer to
(A) i gene
(B) Operator locus
(C) Promoter
(D) z gene
386. The
enzymes encoded by z, y and a genes of lac operon are inducible, and their
inducer is
(A) Lactose
(B) Allo-lactose
(C) Catabolite
gene activator protein
(D) All of
these
387. Binding
of RNA polymerase holoenzymes to the promoter region of lac operon is
facilitated by
(A) Catabolite
gene activator protein (CAP)
(B) cAMP
(C) CAP-cAMP complex
(D) None of
these
388. Lactose
or its analogues act as positive
regulators of lac operon by
(A) Attaching
to i gene and preventing its expression
(B) Increasing
the synthesis of catabolite gene activator
protein
(C) Attaching
to promoter region and facilitating the binding of RNA polymerase holoenzyme
(D) Binding to repressor subunits so that the repressor
cannot attach to the operator locus
389. Expression
of structural genes of lac operon
is affected by all the following except
(A) Lactose or
its analogues
(B) Repressor
tetramer
(C) cAMP
(D) CAP-cAMP
complex
390. The
coding sequences in lac operon
include
(A) i gene
(B) i gene,
operator locus and promoter
(C) z, y and a
genes
(D) i, z, y and a genes
391. Mutations
can be caused by
(A) Ultraviolet
radiation
(B) Ionising
radiation
(C) Alkylating agents
(D) All of
these
392. Mutations
can be caused by
(A) Nitrosamine
(B) Dimethyl
sulphate
(C) Acridine
(D) All of these
393. Nitrosamine
can deaminate
(A) Cytosine to form uracil
(B) Adenine to form xanthine
(C) Guanine to
form hypoxanthine
(D) All of
these
394. Exposure
of DNA to ultraviolet radiation
can lead to the formation of
(A) Adenine
dimers
(B) Guanine
dimers
(C) Thymine dimers
(D) Uracil
dimers
395. Damage
to DNA caused by ultraviolet
radiation can be repaired by
(A) uvr ABC
excinuclease
(B) DNA
polymerase I
(C) DNA ligase
(D) All of these
396. Xeroderma
pigmentosum results from a
defect in
(A) uvr ABC excinuclease
(B) DNA
polymerase I
(C) DNA ligase
(D) All of
these
397. All the
following statements about xeroderma pigmentosum are true except
(A) It is a genetic
disease
(B) Its inheritance is autosomal dominant
(C) uvr ABC
excinuclease is defective in this disease
(D) It results
in multiple skin cancers
398. Substitution
of an adenine base by guanine in DNA is known as
(A)
Transposition
(B) Transition
(C)
Transversion
(D) Frameshift
mutation
399. Substitution
of a thymine base by adenine in DNA is known as
((A)
Transposition
(B) Transition
(C) Transversion
(D) Frameshift
mutation
400. A point
mutation results from
(A) Substitution of a base
(B) Insertion
of a base
(C) Deletion of
a base
(D) All of
these
401. Substitution
of a base can result in a
(A) Silent
mutation
(B) Mis-sense
mutation
(C) Nonsense
mutation
(D) All of these
402. A silent
mutation is most likely to result from
(A)
Substitution of the first base of a codon
(B) Substitution of the third base of a codon
(C) Conversion
of a nonsense codon into a sense codon
(D) Conversion
of a sense codon into a nonsense codon
403. The
effect of a mis-sense mutation can be
(A) Acceptable
(B) Partially
acceptable
(C)
Unacceptable
(D) All of these
404. Amino
acid sequence of the encoded
protein is not changed in
(A) Silent mutation
(B) Acceptable
mis-sense mutation
(C) Both (A)
and (B)
(D) None of
these
405. Haemoglobin
S is an example of a/an
(A) Silent
mutation
(B) Acceptable
mis-sense mutation
(C)
Unacceptable mis-sense mutation
(D) Partially acceptable mis-sense mutation
406. If the
codon UAC on mRNA changes into UAG as a result of a base substitution in
DNA, it will result in
(A) Silent
mutation
(B) Acceptable
mis-sense mutation
(C) Nonsense mutation
(D) Frameshift
mutation
407. Insertion
of a base in a gene can cause
(A) Change in
reading frame
(B) Garbled
amino acid sequence in the encoded protein
(C) Premature
termination of translation
(D) All of these
408. A
frameshift mutation changes the
reading frame because the genetic code
(A) Is
degenerate
(B) Is
overlapping
(C) Has no punctuations
(D) Is
universal
409. Suppressor
mutations occur in
(A) Structural
genes
(B) Promoter
regions
(C) Silencer
elements
(D) Anticodons of tRNA
410. Suppressor
tRNAs can neutralize the
effects of mutations in
(A) Structural genes
(B) Promoter
regions
(C) Enhancer
elements
(D) All of
these
411. Mutations
in promoter regions of genes
can cause
(A) Premature termination of translation
(B) Change
in reading frame of downstream structural gene
(C) Decreased efficiency of transcription
(D) All of
these
412. Mitochondrial
protein synthesis is inhibited
by
(A) Cycloheximide
(B) Chloramphenicol
(C) Diptheria
toxin
(D) None of
these
413. All of
the following statements about puromycin are true except
(A) It is an alanyl tRNA analogue
(B) It
causes premature termination of protein synthesis
(C) It inhibits
protein synthesis in prokaryotes
(D) It
inhibits protein synthesis in eukaryotes
414. Leucine
zipper motif is seen in some helical proteins when leucine residues appear at every
(A) 3rd
position
(B) 5th
position
(C) 7th position
(D) 9th
position
415. Zinc
finger motif is formed in some proteins by binding of zinc to
(A) Two
cysteine residues
(B) Two
histidine residues
(C) Two
arginine residues
(D) Two cysteine and two histidine residues or
two pairs of two cysteine residues each
416. Restriction
endonucleases are present in
(A) Viruses
(B) Bacteria
(C) Eukaryotes
(D) All of
these
417. Restriction
endonucleases split
(A) RNA
(B) Single
stranded DNA
(C) Double stranded DNA
(D) DNA-RNA
hybrids
418. Restriction
endonucleases can recognise
(A) Palindromic sequences
(B) Chimeric
DNA
(C) DNA-RNA
hybrids
(D) Homopolymer
sequences
419. All of
the following statements about restriction endonucleases are true except:
(A) They are
present in bacteria
(B) They act on
double stranded DNA
(C) They
recognize palindromic sequences
(D) They always produce sticky ends
420. Which of
the following is a palindromic
sequence
(A) 5′−
ATGCAG − 3′
(B) 3′−
TACGTC − 5′
(C) 5′− CGAAGC − 3′
(D) 3′− GCTTCG − 5′
421. In
sticky ends produced by restriction
endonucleases
(A) The 2
strands of DNA are joined to each other
(B) The DNA
strands stick to the restriction endonuclease
(C) The ends of a double stranded fragment are overlapping
(D) The ends of
a double stranded fragment are non overlapping
422. All of
the following may be used as ex-
pression vectors except
(A) Plasmid
(B)
Bacteriophage
(C) Baculovirus
(D) E. coli
423. A
plasmid is a
(A) Single
stranded linear DNA
(B) Single stranded circular DNA
(C) Double stranded
linear DNA
(D) Double stranded circular DNA
424. Fragments
of DNA can be identified by the
technique of
(A) Western
blotting
(B) Eastern
blotting
(C) Northern
blotting
(D) Southern blotting
425. A
particular RNA in a mixture can be
identified by
(A) Western
blotting
(B) Eastern
blotting
(C) Northern blotting
(D) Southern
blotting
426. A
radioactive isotope labeled cDNA probe
is used in
(A) Southern
blotting
(B) Northern
blotting
(C) Both (A) and (B)
(D) None of
these
427. An antibody
probe is used in
(A) Southern
blotting
(B) Northern
blotting
(C) Western blotting
(D) None of
these
428. A
particular protein in a mixture can be
detected by
A) Southern
blotting
(B) Northern
blotting
(C) Western blotting
(D) None of these
429. The first
protein synthesized by recombinant DNA technology was
(A)
Streptokinase
(B) Human
growth hormone
(C) Tissue
plasminogen activator
(D) Human insulin
430. For production
of eukaryotic protein by recombinant DNA technology in bacteria,
the template used is
(A) Eukaryotic
gene
(B) hnRNA
(C) mRNA
(D) All of
these
431. Monoclonal
antibodies are prepared by
cloning
(A) Myeloma
cells
(B) Hybridoma cells
(C)
T-Lymphocytes
(D)
B-Lymphocytes
432. Myeloma
cells are lacking in
(A) TMP
synthetase
(B) Formyl transferase
(C) HGPRT
(D) All of
these
433. Hybridoma
cells are selected by culturing
them in a medium containing
(A) Adenine,
guanine, cytosine and thymine
(B) Adenine,
guanine, cytosine and uracil
(C)
Hypoxanthine, aminopterin and thymine
(D) Hypoxanthine, aminopterin and thymidine
434. Myeloma
cells and lymphocytes can be
fused by using
(A) Calcium
chloride
(B) Ethidium
bromide
(C) Polyethylene glycol
(D) DNA
polymerase
435. Trials
for gene therapy in human beings were first carried out, with considerable
success, in a genetic disease called
(A) Cystic
fibrosis
(B) Thalassemia
(C) Adenosine deaminase deficiency
(D) Lesch-Nyhan
syndrome
436. Chimeric
DNA
(A) Is found in
bacteriophages
(B) Contains unrelated genes
(C) Has no
restriction sites
(D) Is
palindromic
437. Which of
the following may be used as a
cloning vector?
(A) Prokaryotic
plasmid
(B) Lambda
phage
(C) Cosmid
(D) All of these
438. The
plasmid pBR322 has
(A) Ampicillin
resistance gene
(B) Tetracycline resistance gene
(C) Both (A) and (B)
(D) None of
these
439. Lambda
phage can be used to clone DNA
fragments of the size
(A) Upto 3
kilobases
(B) Upto 20 kilobases
(C) Upto 45
kilobases
(D) Upto 1,000
kilobases
440. DNA
fragments upto 45 kilobases in size
can be cloned in
(A) Bacterial
plasmids
(B) Lambda
phage
(C) Cosmids
(D) Yeast
artificial chromosomes
441. A cosmid
is a
(A) Large
bacterial plasmid
(B) Viral
plasmid
(C) Hybrid of plasmid and phage
(D) Yeast
plasmid
442. Polymerase
chain reaction can rapidly
amplify DNA sequences of the size
(A) Upto 10 kilobases
(B) Upto 45
kilobases
(C) Upto 100
kilobases
(D) Upto 1,000
kilobases
443. The DNA
polymerase commonly used in
polymerase chain reaction is obtained from
(A) E. coli
(B) Yeast
(C) T.aquaticus
(D) Eukaryotes
444. Base
sequence of DNA can be determined
by
(A)
Maxam-Gilbert method
(B) Sanger’s
dideoxy method
(C) Both (A) and (B)
(D) None of
these
445. From a
DNA-RNA hybrid, DNA can be
obtained by addition of
(A) DNA B
protein and ATP
(B) Helicase
and ATP
(C) DNA
topoisomerase I
(D) Alkali
446. Optimum
temperature of DNA polymerase of T. aquaticus is
(A) 30°C
(B) 37°C
(C) 54°C
(D) 72°C
447. In
addition to Taq polymerase, polymerase chain reaction requires all of the
following except
(A) A template
DNA
(B)
Deoxyribonucleoside triphosphates
(C) Primers
(D) Primase
448. DNA polymerase
of T. aquaticus is preferred to that of E. coli in PCR
because
(A) It
replicates DNA more efficiently
(B) It doesn’t
require primers
(C) It is not denatured at the melting
temperature of DNA
(D) It doesn’t
cause errors in replication
449. Twenty
cycles of PCR can amplify DNA:
(A) 220 fold
(B) 202
fold
(C) 20 x 2
fold
(D) 20 fold
450. Transgenic
animals may be prepared by
introducing a foreign gene into
(A) Somatic
cells of young animals
(B) Testes and
ovaries of animals
(C) A viral
vector and infecting the animals with the viral vector
(D) Fertilised egg and implanting the egg into a foster
mother
451. Yeast
artificial chromosome can be used to amplify DNA sequences of the size
(A) Upto 10 kb
(B) Upto 45 kb
(C) Upto 100 kb
(D) Upto 1,000 kb
452. DNA
finger printing is based on the presence in DNA of
(A) Constant number
of tandem repeats
(B) Varibale number of tandem repeats
(C)
Non-repititive sequences in each DNA
(D) Introns in
eukaryotic DNA
453. All the
following statements about restriction fragment length polymorphism are true
except
(A) It results
from mutations in restriction sites
(B) Mutations in restriction sites can
occur in coding or non-coding regions of DNA
(C) It is
inherited in Mendelian fashion
(D) It can be used to diagnose any genetic disease
454. Inborn
errors of urea cycle can cause all
the following except
(A) Vomiting
(B) Ataxia
(C) Renal
failure
(D) Mental retardation
455. Hyperammonaemia
type I results from
congenital absence of
(A) Glutamate
dehydrogenase
(B) Carbamoyl phosphate synthetase
(C) Ornithine
transcarbamoylase
(D) None of
these
456. Congenital
deficiency of ornithine
transcarbamoylase causes
(A)
Hyperammonaemia type I
(B)
Hyperammonaemia type II
(C) Hyperornithinaemia
(D)
Citrullinaemia
457. A
ketogenic amino acid among the following is
(A) Leucine
(B) Serine
(C) Threonine
(D) Proline
458. Carbon
skeleton of the following amino acid can serve as a substance for
gluconeogenesis
(A) Cysteine
(B) Aspartate
(C) Glutamate
(D) All of these
459. N-Formiminoglutamate
is a metabolite of
(A) Glutamate
(B) Histidine
(C) Tryptophan
(D) Methionine
460. Methylmalonyl
CoA is a metabolite of
(A) Valine
(B) Leucine
(C) Isoleucine
(D) All of
these
461. Homogentisic
acid is formed from
(A) Homoserine
(B)
Homocysteine
(C) Tyrosine
(D) Tryptophan
462. Maple
syrup urine disease results from
absence or serve deficiency of
(A)
Homogentisate oxidase
(B) Phenylalanine hydroxylase
(C) Branched
chain amino acid transaminase
(D) None of these
463. Which of
the following is present as a marker in lysosomal enzymes to direct
them to their destination?
(A)
Glucose-6-phosphate
(B) Mannose-6-phosphate
(C) Galactose-6-phosphate
(D) N-Acetyl
neuraminic acid
464. Marfan’s
syndrome results from a
mutation in the gene coding:
(A) Collagen
(B) Elastin
(C) Fibrillin
(D) Keratin
465. All the
following statements about
fibronectin are true except
(A) It is glycoprotein
(B) It is a triple helix
(C) It is
present in extra cellular matrix
(D) It binds
with integrin receptors of cell
466. Fibronectin
has binding sites for all of the following except
(A) Glycophorin
(B) Collagen
(C) Heparin
(D) Integrin
receptor
467. Fibronectin
is involved in
(A) Cell
adhension
(B) Cell movement
(C) Both (A)
and (B)
(D) None of
these
466. Fibronectin has binding sites for all of the following except
(A) Glycophorin
(B) Collagen
(C) Heparin
(D) Integrin
receptor
467. Fibronectin
is involved in
(A) Cell
adhension
(B) Cell movement
(C) Both (A)
and (B)
(D) None of
these
468. Glycoproteins
are marked for destruction by removal of their
(A)
Oligosaccharide prosthetic group
(B) Sialic acid
residues
(C) Mannose
residues
(D) N-terminal amino acids
469. Glycophorin
is present in cell membranes of
(A) Erythrocytes
(B) Platelets
(C) Neutrophils
(D) Liver
470. Selectins
are proteins that can recognise specific
(A) Carbohydrates
(B) Lipids
(C) Amino acids
(D) Nucleotides
471. Hunter’s
syndrome results from absence of
(A)
Hexosaminidase A
(B) Iduronate sulphatase
(C)
Neuraminidase
(D)
Arylsulphatase B
472. A cancer
cell is characterized by
(A)
Uncontrolled cell division
(B) Invasion of neighbouring cells
(C) Spread to
distant sites
(D) All of these
473. If DNA
of a cancer cell is introduced into a normal cell, the recipient cell
(A) Destroys
the DNA
(B) Loses its ability to divide
(C) Dies
(D) Changes into a cancer cell
474. A normal
cell can be transformed into a cancer cell by all of the following except
(A) Ionising
radiation
(B) Mutagenic
chemicals
(C) Oncogenic bacteria
(D) Some
viruses
475. Proto-oncogens
are present in
(A) Oncoviruses
(B) Cancer
cells
(C) Healthy human cells
(D) Prokaryotes
476. All the
following statements about proto oncogenes are true except
(A) They are
present in human beings
(B) They are
present in healthy cells
(C) Proteins
encoded by them are essential
(D) They are expressed only when a healthy cell has
been transformed into a cancer cell
477. Various
oncogens may encode all of the
following except:
(A) Carcinogens
(B) Growth factors
(C) Receptors
for growth factors
(D) Signal
transducers for growth factors
478. Ras
proto-oncogene is converted into oncogene by
(A) A point mutation
(B) Chromosomal
translocation
(C) Insertion
of a viral promoter upstream of the gene
(D) Gene
amplification
479. Ras
proto-oncogene encodes
(A) Epidermal
growth factor (EGF)
(B) Receptor
for EGF
(C) Signal transducer for EGF
(D) Nuclear
transcription factor
480. P 53
gene:
(A) A
proto-oncogene
(B) An oncogene
(C) A tumour suppressor gene
(D) None of
these
481. Retinoblastoma
can result from a mutation in
(A) ras
proto-oncogene
(B) erbB
proto-oncogene
(C) p 53 gene
(D) RB 1 gene
482 All the
following statements about retino blastoma are true except
(A) At least
two mutations are required for its development
(B) One
mutation can be inherited from a parent
(C) Children
who have inherited one mutation develop retinoblastoma at a younger age
(D) RB 1 gene promotes the development of retinoblastoma
483. Ames
assay is a rapid method for detection
of
(A) Oncoviruses
(B) Retroviuses
(C) Chemical carcinogens
(D) Typhoid
484. Amplification
of dihydrofolate reductase gene in a cancer cell makes the cell
(A) Susceptible
to folic acid deficiency
(B) Less
malignant
(C) Resistant to amethopterin therapy
(D) Responsive
to amethopterin therapy
485. Conversion
of a procarcinogen into a
carcinogen often requires
(A) Proteolysis
(B) Microsomal hydroxylation
(C) Exposure to
ultraviolet radiation
(D) Exposure to
X-rays
486. The only
correct statement about onco viruses is
(A) All the
oncoviruses are RNA viruses
(B) Reverse transcriptase is present in
all oncoviruses
(C) Viral oncogenes
are identical to human protooncogens
(D) Both DNA and RNA viruses can be oncoviruses
487. RB 1
gene is
(A) A tumour suppressor gene
(B) Oncogene
(C)
Proto-oncogene
(D) Activated
proto-oncogene
488. Cancer
cells may become resistant to
amethopterin by
(A) Developing
mechanisms to destroy amethopterin
(B) Amplification of dihydrofolate reducatse gene
(C) Mutation in
the dihydrofolate reductase gene so that the enzyme is no longer inhibited by
amethopterin
(D) Developing
alternate pathway of thymidylate synthesis
489. The
major source of NH3 produced by the
kidney is
(A) Leucine
(B) Glycine
(C) Alanine
(D) Glutamine
490. Which of
these methyl donors is not aquanternary ammonium compound?
(A) Methionine
(B) Choline
(C) Betain
(D)
Betainaldehyde
491. L-glutamic
acid is subjected to oxidative deaminition by
(A) L-amino
acid dehydrogenase
(B) L-glutamate dehydrogenase
(C) Glutaminase
(D) Glutamine
synthetase
492. A
prokaryotic ribosome is made up of________ sub units.
(A) 20 S
and 50 S
(B) 30S and 50S
(C) 30S and
60S
(D) 20S and
50S
493. AN
Eukaryotic ribosome is made up of________ sub unit.
(A) 40S and 60S
(B) 40S and
50S
(C) 40S and
80S
(D) 60S and
80 S
494. GTP is
not required for
(A) Capping L
of mRNA
(B) Fusion of
40S and 60S of ribosome
(C) Accommodation
of tRNA amino acid
(D) Formation of tRNA amino acid complex
495. The
antibiotic which inhibits DNA dependent RNA polymerase is
(A) Mitomycin C
(B) Actinomycin d
(C)
Streptomycin
(D) Puromycin
496. The
antibiotic which cleaves DNA is
(A) Actinomycin
d
(B)
Streptomycin
(C) Puromycin
(D) Mitomycin C
497. The
antibiotic which has a structure similar to the amino acyl end of tRNA tyrosine
is
(A) Actinomycin
d
(B)
Streptomycin
(C) Puromycin
(D) Mitomycin c
498. ATP is
required for
(A) Fusion of
40S and 60 S of ribosome
(B) Accommodation tRNA amino acid in a
site of ribosome
(C) Movement of
ribosome along mRNA
(D) formation of tRNA amino acid complex
499. What is
the subcellular site for the bio-
synthesis of proteins?
(A) Chromosomes
(B) Lymosomes
(C) Ribosomes
(D) Centrosomes
500. An
animal is in negative nitrogen balance
when
(A) Intake
exceeds output
(B) New tissue
is being synthesized
(C) Output exceeds intake
(D) Intake is
equal to output
501. When NH3
is perfused through a dog’s liver ______ is formed, while ______ is formed in
the birds liver.
(A) Urea, Uric acid
(B) Urea,
allantoin
(C) Uric acid,
creatinine
(D) Uric acid,
Urea
502. Aspartate
amino transferase uses the following for transamination:
(A) Glutamic
acid and pyruvic acid
(B) Glutamic acid and oxaloacetic acid
(C) Aspartic
acid and pyruvic acid
(D) aspartic
acid and keto adipic acid
503. Which
among the following compounds is not a protein?
(A) Insulin
(B) Hheparin
(C) Mucin
(D) Pepsin
504. Almost
all the urea is formed in this tissue:
(A) Kidney
(B) Urethra
(C) Uterus
(D) Liver
505. A polyribosome
will have about _______ individual ribosomes.
(A) 20
(B) 10
(C) 5
(D) 2
506. Progressive
transmethylation of ethanolamine gives
(A) Creatinine
(B) Choline
(C) Methionine
(D) N-methyl
nicotinamide
507. Genetic
information originates from
(A) Cistron of DNA
(B) Codons of mRNA
(C) Anticodons
of tRNA
(D) Histones of
nucleoproteins
508. The
genetic code operates through
(A) The protein
moiety of DNA
(B) Cistrom of
DNA
(C) Nucleotide sequence of m RNA
(D) The
anticodons of tRNA
509. DNA synthesis
in laboratory was first achieved by
(A) Watson and
crick
(B) Khorana
(C) A.Kornberg
(D) Ochoa
510. Among
the different types of RNA, which one has the highest M.W.?
(A) mRNA
(B) rRNA
(C) yeast RNA
(D) tRNA
511. From DNA
the genetic message is transcribed into this compound:
(A) Protein
(B) mRNA
(C) tRNA
(D) rRNA
512. This
compound has a double helical
structure.
(A) Deoxyribonucleic acid
(B) RNA
(C)
Flavine-adevine dinucleotide
(D)
Nicotinamide adamine dinucleotide
513. The
structural stability of the double helix of DNA is as cribbed largely to
(A) Hydrogen
bonding between adjacent purine bases
(B) Hydrophobic
bonding between staked purine and pyrinuidine nuclei
(C) Hydrogen
bonding between adjacent pyrimidine bases
(D) Hydrogen bonding between purine and pyrimidine
bases
514. Which of
the following statements about nucleic acid is most correct?
(A) Both
pentose nucleic acid and deoxypentose nucleic acid contain the same pyrimidines
(B) Both pentose nucleic acid and deoxypentose nucleic
acid and deoxypentose nucleic acid Contain the same purines
(C) RNA
contains cytosine and thymine
(D) DNA and RNA
are hydrolysed by weak alkali
515. Acid
hydrolysis of ribonucleic acid would yield the following major products:
(A) d-
deoxyribose, cytosine, adenine
(B) d-ribose,
thymine, Guanine
(C) d-ribose,
cytosine, uracil, thymine
(D) d-ribose, uracil, adenine, guanine, cytosine
516. RNA does
not contain
(A) adenine
(B) OH methyl cytosine
(C) d-ribose
(D) Uracil
517. Which of
the following statements is
correct?
(A) a nucleo
protein usually contain deoxy sugars of the hexose type
(B)
Nucleoproteins are usually absent from the cytoplasm
(C)
Nucleoproteins usually are present in the nucleus only
(D) Nucleoproteins usually occur in the nucleus and
cytoplasm
518. Whcih of
the following compound is present in RNA but absent from DNA?
(A) Thymine
(B) Cytosine
(C) Uracil
(D) Guanine
519. Nucleic
acids can be detected by means of their absorption maxima near 260 nm.
Their absorption in this range is due to
(A) Proteins
(B) Purines and pyrimidines
(C) Ribose
(D) Deoxyribose
520. Which of
the following contains a deoxy
sugar?
(A) RNA
(B) DNA
(C) ATP
(D) UTP
521. DNA is
(A) Usually
present in tissues as a nucleo protein and
cannot be separated from its protein
component
(B) A long chain polymer in which the internucleotide
linkages are of the diester type between
C-3’ and C-5’
(C) Different
from RNA since in the latter the internucleotide linkages are between C-2’ and C-5’
(D) Hydrolyzed
by weal alkali (pH9 to 100°C)
522. Nobody is the name given to
(A) Ribosome
(B) Microsome
(C) Centrosome
(D) Nucleosome
523. Transcription
is the formation of
(A) DNA from a
parent DNA
(B) mRNA from a
parent mRNA
(C) pre mRNA from DNA
(D) protein
through mRNA
524. Translation
is the formation of
(A) DNA from DNA
(B) mRNA from DNA
(C) Protein
through mRNA
(D) mRNA from
pre mRNA
525. Sigma
and Rho factors are required for
(A) Replication
(B)
Transcription
(C) Translation
(D)
Polymerisation
526. The
genine of φ×174 bacteriophage is interesting in that if contains
(A) No DNA
(B) DNA with
uracil
(C) Single stranded DNA
(D) Triple
standard DNA
527. Okasaki
fragments are small bits of
(A) RNA
(B) DNA
(C) DNA with RNA heads
(D) RNA with
DNA heads
528. In
addition to the DNA of nucleus there DNA is
(A) Mitochondrian
(B) Endoplasmic
reticulum
(C) Golgi
apparatus
(D) Plasma
membrane
529. The
mitochondrial DNA is
(A) Like the
nuclear DNA in structure
(B) Single
stranded, linear
(C) Double stranded, circular
(D) Single
stranded, circular
530. A
synthetic RNA having the sequence of UUUUUU (Poly U) will give a protein
having poly ______.
(A) Alamine
(B) Phenyl alanine
(C) Glycine
(D) Methionine
531. Lac
operon of E. coli contains _______ is continuity.
(A) Regulator
and operator genes only
(B) Operator and structural genes only
(C) Regular and
structural genes only
(D) Regulator, operator and structural genes
532. A mRNA
of eukaryotes can code for
(A) Only one polypeptide
(B) Two
polypeptides
(C) Three
polypeptides
(D) Five polypeptides
533. mRNA of
prokaryotes can code for
(A) More than one polypeptide
(B) Only one
polypeptide
(C) Many exons
and introns
(D) Introns
only
534. DNA
directed RNA polymerase is
(A) Replicase
(B) Transcriptase
(C) Reverse
transcriptase
(D) Polymerase
III
535. RNA
directed DNA polymerase is
(A) Replicase
(B)
Transcriptase
(C) Reversetranscriptase
(D)
Polymerase-III
Q536. RNA synthesis requires
(A) RNA primer
(B) RNA
template
(C) DNA template
(D) DNA primer
537. The mRNA
ready for protein synthesis has the ________ cap.
(A) ATP
(B) CTP
(C) GTP
(D) UTP
538. mRNA
ready for protein synthesis has the poly _______ toil.
(A) G
(B) A
(C) U
(D) C
539. The
codon for phenyl Alanine is
(A) AAA
(B) CCC
(C) GGG
(D) UUU
540. Blue
print for genetic information residues
in
(A) mRNA
(B) tRNA
(C) rRNA
(D) DNA
541. Genes
are
(A) RNA
(B) DNA
(C)
lipoproteins and
(D)
Chromoproteins
542. Codons
are in
(A) DNA
(B) mRNA
(C) tRNA
(D) rRNA
543. The
genetic code operates via
(A) The protein
moiety of DNA
(B) The base sequences of DNA
(C) The nucleotide sequence of mRNA
(D) The base
sequence of tRNA
544. Urine
bases with methyl substituents occurring in plants are
(A) Caffeine
(B) Theophylline
(C) Theobromine
(D) All of these
545. Genetic
information in human beings is stored in
(A) DNA
(B) RNA
(C) Both (A)
and (B)
(D) None of
these
546. All
following are naturally occurring nucleotides except
(A) Cyclic AMP
(B) ATP
(C) DNA
(D) Inosine
monophosphate
547. If the
amino group and a carboxylic group of the amino acid are attached to
same carbon atom, the amino acid is called as
(A) Alpha
(B) Beta
(C) Gamma
(D) Epsilon
548. If in a
nucleic acid there are more than 8000 nucleotides it is most likely
(A) RNA
(B) DNA
(C) Both (A)
and (B)
(D) None of
these
549. Genetic
information in human beings is stored in
(A) RNA
(B) DNA
(C) Both (A)
and (B)
(D) mRNA
550. In RNA,
apart from ribose and phosphate, all following are present except
(A) Adenine
(B) Guanine
(C) Thymine
(D) Cytosine
551. Which of
the following gives a positive Ninhydrin test?
(A) Reducing
sugar
(B)
Triglycerides
(C) α-amino acids
(D)
Phospholipids
552. A Gene
is
(A) A single protein
molecule
(B) A group of chromosomes
(C) An
instruction for making a protein molecule
(D) A bit of DNA molecule
553. In DNA,
genetic information is located in
(A) Purine
bases
(B) Pyrimidine
bases
(C) Purine and pyrimidine bases
(D) sugar
554. Which
one of the following is not a constituent of RNA?
(A) Deoxyribose
(B) Uracil
(C) Adenine
(D) Thymine
555. Which of
the following are nucleo proteins?
(A) Protamines
(B) Histones
(C) Deoxy and
Ribo nucleo proteins
(D) All of these
556. The
total RNA in cell tRNA constitutes
(A) 1-10%
(B) 10-20%
(C) 30-50%
(D) 50-80%
557. Unit of
genetic information:
(A) DNA
(B) RNA
(C) Cistron
(D) None of
these
558. Anticodon
sequence are seen in
(A) tRNA and transcribed DNA strand
(B) tRNA and complementary DNA strand
(C) mRNA
(D) mRNA and
complementary DNA strand
559. cAMD is
destroyed by
(A) Adenylate
cyclase
(B) Phosphodiesterase
(C) Synthetase
phosphatase
(D) Synthetase
kinase
560. Restriction
enzymes have been found in
(A) Humans
(B) Birds
(C) Bacteria
(D)
Bacteriophase
561. Sulphur
is not present in
(A) Thiamine
(B) Lipic acid
(C) Thymine
(D) Biotin
562. Which
one of the following binds to specific nucleotide sequences?
(A) RNA polymerase
(B) Repressor
(C) Inducer
(D) Restriction
563. Using
written convertion which one of the following sequences is complimentary to
TGGCAGCCT ?
(A) ACC GTC GGA
(B) ACC GUC GGA
(C) AGG CTG CCA
(D) TGG CTC GGA
564. Ribosomes
similar to those of bacterial
found in
(A) Plant nucei
(B) Cardiac
muscle cytoplasm
(C) Liver
endoplasmic reticulum
(D) Neuronal
cytoplasm
565. The
mechanism of synthesis of DNA andRNA are similar in all the following ways
except
(A) They involve release of pyrophosphate from each nucleotide added
(B) They
require activated nucleotide precursor and
Mg2+
(C) The
direction of synthesis is 5’ → 3’
(D) They
require a primer
566. Template-directed
DNA synthesis occurs in
all the following except
(A) The
replication fork
(B) Polymerase chain reaction
(C) Growth of
RNA tumor viruses
(D) Expression
of oneogenes
567. Which
one of the following statements correctly describes eukaryotic DNA?
(A) They
involve release of pyrophosphate from each
nucleotide precussor and Mg2+
(B) The
direction of synthesis is
(C) They require a primer 5’ → 3’
(D) None of
these
568. Which
one of the following causes frame shift mutation?
(A) Transition
(B)
Transversion
(C) Deletion
(D)
Substitution of purine to pyrimidine
569. Catabolism
of thymidylate gives
(A) α-alanine
(B) β-alanine
(C)
α-aminoisobutyrate
(D) β-aminoisobutyrate
570. Glycine
gives __________ atoms of purine.
(A) C2,
C3
(B) C4, C5 and N7
(C) C4,
C5 and N9
(D) C4,
C6 and N7
571. A common
substrate of HGPRTase, APRTase and PRPP glutamyl amidotransferase is
(A) Ribose 5
phosphate
(B) Phosphoribosyl pyrophosphate
(C) Hypoxanthine
(D) Adenosine
572. Carbon
6-of purine skeleton comes from
(A) Atmospheric CO2
(B) 1
carbon carried by folate
(C) Betoine
(D) Methionine
573. Uric
acid is the catabolic end product of
(A) Porphyrine
(B) Purines
(C) Pyrimidines
(D) Pyridoxine
574. Diphenylamine
method is employed in the
quantitation of
(A) Nucleic
acid
(B) RNA
(C) DNA
(D) Proteins
575. Orcinol
method is employed in the quanti-
tation of
(A) Nucleic
acid
(B) DNA
(C) RNA
(D) Proteins
576. Nucleic
acid show strong absorption at
one of the wavelength:
(A) 280 nm
(B) 220 nm
(C) 360 nm
(D) 260 nm
577. tRNA has
(A) Clover leaf structure
(B) anticodon
arm
(C) poly ‘A’
tay 3’
(D) Cap at 5’
end
578. Which
one of the following contributes nitrogen atoms to both purine and
pyrimidine rings?
(A) Aspartate
(B) Carbanoyl
phosphate
(C)
Carbondioxide
(D)
Tetrahydrofolate
579. The four
nitrogen atoms of purines are derived from
(A) Urea and NH3
(B) NH3,
Glycine and Glutamate
(C) NH3,
Asparate and Glutamate
(D) Aspartate, Glutamine and Glycine
580. A drug
which prevents uric acid synthesis by inhibiting the enzyme Xanthine oxi-
dase is
(A) Aspirin
(B) Allopurinal
(C) Colchicine
(D) Phenyl
benzoate
581. Glycine contributes to the following C and N of purine nucleus:
(A) C1,
C2 and N7
(B) C8,
C8 and N9
(C) C4, C5 and N7
(D) C4,
C5 and N9
582. Insoinic acid is the biological precursor
of
(A)
Cytosine and Uric acid
(B) Adenylve acid and Glucine floc acid
(C)
Orotic acid and Uridylic acid
(D)
Adenosine acid Thymidine
583. The
probable metabolic defect in gents is
(A) A
defect in excretion of uric acid by kidney
(B) An
overproduction of pyrimidines
(C) An overproduction of uric acid
(D) Rise
in calcium leading to deposition of calcium urate
584. In
humans, the principal break down product of purines is
(A) NH3
(B)
Allantin
(C)
Alanine
(D) Uric acid
585. A
key substance in the committed step of
pyrimidines biosynthesis is
(A)
Ribose-5-phosphate
(B) Carbamoyl phosphate
(C) ATP
(D)
Glutamine
586. In
humans, the principal metabolic product of pyrimidines is
(A) Uric
acid
(B)
Allantoin
(C)
Hypoxanthine
(D) β-alanine
587. In
most mammals, except primates, uric acid is metabolized by
(A) Oxidation to allantoin
(B)
Reduction to NH3
(C)
Hydrolysis to allantoin
(D)
Hydrolysis to NH3
588. Two
nitrogen of the pyrimidines ring are obtained from
(A)
Glutamine and Carbamoyl-p
(B) Asparate and Carbamoyl-p
(C)
Glutamate and NH3
(D)
Glutamine and NH3
589. All
are true about lesch-nyhan syndrome except
(A)
Produces self-mutilation
(B) Genetic deficiency of the enzyme
(C)
Elevated levels of uric acid in blood
(D)
Inheritance is autosomal recessive
590. Synthesis
of GMP and IMP requires the following:
(A) NH3
NAD+, ATP
(B) Glutamine, NAD+, ATP
(C) NH3,
GTP, NADP+
(D)
Glutamine, GTP, NADP+
591. Which
pathway is correct for catabolism of purines to form uric acid?
(A)
Guanylate→Adenylate→Xanthine→hypoxanthine→Uric acid
(B)
Guanylate→inosinate→Xanthine→hypoxanthine→Uric acid
(C) Adenylate→Inosinate→Xanthine
hypoxanthine→Uric acid
(D) Adenylate→Inosinate→hypoxanthine Xanthine→Uric acid
592. Polysemes
do not contain
(A)
Protein
(B) DNA
(C) mRNA
(D) rRNA
593. The
formation of a peptide bond during the elongation step of protein synthesis results
in the splitting of how many high energy bonds?
(A) 1
(B) 2
(C) 3
(D) 4
594. Translocase
is an enzyme required in the process of
(A) DNA
replication
(B) RNA
synthesis
(C)
Initiation of protein synthesis
(D) Elongation of peptides
595. Nonsense
codons bring about
(A)
Amino acid activation
(B)
Initiation of protein synthesis
(C) Termination of protein synthesis
(D)
Elongation of polypeptide chains
596. Which
of the following genes of the E.coli “Lac operon” codes for a constitutive
protein?
(A) The
‘a’ gene
(B) The ‘i’ gene
(C) The
‘c’ gene
(D) The
‘z’ gene
597. In
the process of transcription, the flow of genetic information is from
(A) DNA
to DNA
(B) DNA
to protein
(C) RNA
to protein
(D) DNA to RNA
598. The
anticodon region is an important part of the structure of
(A) rRNA
(B) tRNA
(C) mRNA
(D)
hrRNA
599. The
region of the Lac operon which must be free from structural gene transcription to
occur is
(A) The operator locus
(B) The
promoter site
(C) The
‘a’ gene
(D) The
‘i’ gene
600. Another
name for reverse transcriptase is
(A) DNA
dependent DNA polymerase
(B) DNA
dependent RNA polymerase
(C) RNA dependent DNA polymerase
(D) RNA
dependent RNA polymerase
601. In
the ’lac operon’ concept, which of the following is a protein?
(A)
Operator
(B) Repressor
(C)
Inducer
(D)
Vector
602. Degeneracy
of the genetic code denotes the existence of
(A) Base
triplets that do not code for any amino acids
(B) Codons consisting of only two bases
(C)
Codons that include one or more of the unusual bases
(D)
Multiple codons for a single amino acid
603. The
normal function of restriction endonucleases is to
(A)
Excise introns from hrRNA
(B) Polymerize nucleotides to form RNA
(C)
Remove primer from okazaki fragments
(D) Protect bacteria from foreign DNA
604. In
contrast to Eukaryotic mRNA, prokaryotic mRNA is characterized by
(A) Having 7-methyl guanosine triphosphate at the
5’ end
(B)
Being polycystronic
(C)
Being only monocystronic
(D)
Being synthesized with introns
605. DNA
ligase of E. coli requires which of the
following co-factors?
(A) FAD
(B) NAD+
(C) NADP+
(D) NADH
606. Which
of the following is transcribed during repression?
(A)
Structural gene
(B)
Promoter gene
(C) Regulator gene
(D)
Operator gene
607. mRNA
is complementary copy of
(A) 5′-3′ strand of DNA+
(B)
3′-5′ strand of DNA
(C) Antisense
strand of DNA
(D) tRNA
608. Synthesis
of RNA molecule is terminated by a signal which is recognised by
(A)
α-factor
(B)
β-factor
(C)
δ-factor
(D) ρ
609. The
binding of prokaryotic DNA dependent RNA polymerase to promoter sits of genes
is inhibited by the antibiotic:
(A)
Streptomycin
(B) Rifamcin
(C)
Aueromycin
(D)
Puromycin
610. In
E. coli the chain initiating amino acid in protein synthesis is
(A) N-formyl methionine
(B)
Methionine
(C)
Serine
(D)
Cysteine
611. Amanitin
the mushroom poison inhibits
(A)
Glycoprotein synthesis
(B) ATP
synthesis
(C) DNA
synthesis
(D) mRNA synthesis
612. How
many high-energy phosphate bond equivalents are required for amino acid
activation in protein synthesis?
(A) One
(B) Two
(C)
Three
(D) Four
613. Translation
results in the formation of
(A) mRNA
(B) tRNA
(C) rRNA
(D) A protein molecule
614. Elongation
of a peptide chain involves all the following except
(A) mRNA
(B) GTP
(C) Formyl-Met-tRNA
(D) Tu,
TS and G factors
615. The
‘rho’ (ρ) factor is involved
(A) To
increase the rate of RNA synthesis
(B) In
binding catabolite repressor to the promoter region
(C) In proper termination of transcription
(D) To
allow proper initiation of transcriptide
616. In
the biosynthesis of c-DNA, the joining
enzyme ligase requires
(A) GTP
(B) ATP
(C) CTP
(D) UTP
617. Which
one of the following binds to specific nucleotide sequences that are upstream
and most distant from the start
site?
(A) RNA polymerase
(B)
Repressor
(C)
Inducer
(D)
Restriction
618. Using
written convention which one of the following sequences is complimentary to
TGGCAGCCT?
(A) ACCGTCGGA
(B)
ACCGUCGGA
(C)
AGGCTGCCA
(D)
TGGCTCGGA
619. Ribosomes
similar to those of bacteria found in
(A) Plant nuclei
(B) Cardiac
muscle cytoplasm
(C)
Liver endoplasmic reticulum
(D)
Neuronal cytoplasm
620. The
mechanism of synthesis of DNA and RNA are similar to all the following ways
except
(A) They
involve release of pyrophosphate from each nucleotide added
(B) They
require activated nucleotide precursor and Mg2+
(C) The
direction of synthesis is
(D) They require a primer
621. Template-directed
DNA synthesis occurs in all the following except
(A) The
replication fork
(B) Polymerase chain reaction
(C) Growth of RNA tumor viruses
(D)
Expression of oncogenes
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