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YuashaLe
Molecular Basis of Inheritance 08
136. Which type of nucleotide is present in RNA?
A. Adenine, cytosine, thymine
B.Adenine, guanine, uracil
C. Adenine, thymine, uracil
D. Adenine,guanine, thyming
137. How many base pairs of DNA helix does a typical nucleosome contain?
A. 100 bp
B200 bp
C. 300 bp
D. 400 bp
138.Why does the distance between two polynucleotide chains in DNA remain almost constant?
ADue to hydrogen bonds between bases
B. Due to phosphodiester linkages
C. Due to glycosidic linkages
D. Due to peptide linkages
139.Which strain of Streptococcus pneumoniae bacteria is virulent and capable of causing
pneumonia in mice?
A.Smooth (S) strain
B. Rough (R) strain
LeMucous-coated strain
D. Heat-killed strain
140. What did viruses grown in the presence of radioactive phosphorus contain?
ARadioactive DNA
B. Radioactive protein
C. Radioactive sulfur
D. Radioactive RNA
141. Which nucleic acid molecule is more prone to mutation due to its instability?
A. DNA
wRNA
C. Both DNA and RNA mutate at the same rate
D. Neither DNA nor RNA
142. What role does RNA play in protein synthesis?
A. RNAserves as a template for DNA replicatio
RNA Carries genetic information from DNA to ribosomes
for protein
C. RNA stabilizes DNAstructure. synthesis.
D. RNA catalyzes chemical reactions in the cel.
143. What did Taylor and colleagues studyin their
A. DNA replication in bacteria
experiment involving Vicia faba?
B. DNA repair mechanisms in plants
cONA replication in plant chromosomes
D. RNA synthesis in bacteria
144. What is the main
enzyme involved in the process
A. RNA-dependent RNA polymerase of DNA replication?
PONA-dependent DNA polymerase
C. RNA-dependent DNA
polymerase
D. DNA-independent RNA
polymerase
145. What is the
function of a promoter in a
A. It provides the
binding site for ribosomes.
transcription unit?
B.It provides the binding
site for RNA
C. It codes for
amino acids.
polymerase.
D. It terminates
transcription.
146. What is a
cistron?
A. A
segment of DNA coding for tRNA
or rRNA
w8.A segment of DNA coding
for a polypeptide
C. Asegment of RNA
coding for a protein
D. A
segment of DNA containing introns
)147.What happens when the RNA polymerase reaches
the terminator region during
transcription?
A. lt continues elongation indefinitely.
B. Thenascent RNAfalls off along with the RNA
polymerase.
C. It binds more strongly to the DNA.
8.itcatalyzes the formation of a peptide bond.
148. Which step of transcription is catalyzed by RNA polymerase?
A. Initiation
YElongation
C. Termination
D. Processing
processing in eukarvotes?
140 What modification occurs at the 5-end of hnRNA during
Capping
B. Tailing
C. Splicing
D. Elongation
defined
method for synthesizing RNA molecules with
150. Which scientist developed a chemical
combinations of bases?
A. James Watson
B. Har Gobind Khorana
C. Francis Crick
D. Severo Ochoa
initiator codon and codes for Methionine?
151. Which codon acts as both an
A. UAA
B. UAG
C. UGA
B.AUG
resulting in the substitution of valine for
152. Which disease is caused by a point mutation
glutamate in the beta globin chain?
A. Cystic fibrosis
B.Sickle cellanemia
C. Huntington's disease
D.Thalassemia
153.Which part of tRNA is complementary to the codon on mRNA?
A. Initiator end
B. Amino acid acceptor end
Anticodon loop
D. Secondary structure
l 6W
0 h
Vlactos
ribosome in translation?
154. What is the role of the
A. Catalyzing the formation of mRNA
acids
B. Breaking down amino
transcription
LInitiatingthe process of
peptide bonds and protein synthesis
D. Facilitating the formation of
in translation?
155. What is the role of the release factor
A. Initiating the translation process
B.Catalyzing the formation of peptide bonds
C. Binding to the stop codon and terminating translation
D. Assisting in the charging of tRNA
156.Which of the following statements about the genetic code is correct?
AEach codon codes for multiple amino acids.
B.The genetic code is read in a non-contiguous fashion.
C. AUG codes for both Methionine and the stop codon.
Á. There are no tRNAs for stop codons.
157. In prokaryotes, which site is predominantly involved in the control of gene expression?
A. Translation initiation site
B. Transcription initiation site
. Replication origin site
D. Termination site
158. What type of molecule serves as an adapter between mRNAand amino acids during
translation?
A. tRNA
B. mRNA
C. rRNA
DNA
159. What is the primary function of the beta-galactosidase enzyme encoded by the z gene in the
lac operon?
ANydrolysis of lactose
B. Increase in permeability of the cell to lactose
C. Synthesis of lactose
D. Regulation of the lac operon
enzyme catalvzes the hvdrolysis of lactose in E. coli, playing a key role in
l60 Which specitic
jactose metabo1sm regulation?
A. DNA p o l y m e r a s e
B.RNA polymerase
Beta-galactosidase
D Ligase
chromosomes, were sequenced as
chromosomes,
including autosomes and sex
many
161. How
Project?
Genome
Human
part of the
A. 23 chromosomes
22 chromosomes
C. 2 4 c h r o m o s o m e s
D. 2 6 c h r o m o s o m e s
known human gene?
following genes is cited as the largest
162. Which of the
A. BRCA1
B. TP53
Dystrophin
D. Hemoglobin
whole-genome
availability of
researchers traditionally
study genes before the
163. How did
sequences?
few genes at a time
A. By studying one or a
non-coding regions of DNA
B. By focusing only on
simultaneously
.By analyzing the entire genome
theoretical models
D. By relying solely on
fingerprinting?
using VNTR probes in DNA
164. What is the purpose of
A.To amplify DNA fragments
polymorphisms
B. To identify single nucleotide
A. To visualize repetitive DNA sequences
regions
D. To detect mutations in coding
sensitivity of DNA fingerprinting?
165. Which technology has increased the
A.Southern blot hybridization
Autoradiography
C. Polymerase chain reaction (PCR)
D. Electrophoresis
1ncorTectWith respect to the structure af,
lis Which ofthe tollowing statennents 1s
polynucleotide chain?
A In DNA. the nitrogenous base Thymine TornS a nucieOsidewith deoxyribose to give
deoxythymidine.
The nitrogenous base is attached to the 1' carbon of the sugar via an N-glycosdic bond
cThe phosphate group is always attached to the 3 OW of the sugar forming aphosphoester
bond.
n denssive nucleotides in a DNA strand are linked
through 3-5 phosphodiester bonds.
7Which of the following statements
provides the most accurate rcason for the transition
from RNA to DNA as the primary genetic material
during evolution?
A. RNA could not participate in catalytic
functions essential for early life forms.
B. RNA was chemically morestable than
DNAand thus better suited for long-term
storge. information
. DNA evolved from RNA due to its
enhanced stability and ability to repair itself
complementary base pairing. via
D. DNA was the original genetic
material, and RNAevolved later to assist in
protein synthesis.
168. Which of the following
statements is correct regarding the DNA
coli? replication process in E.
1 A. DNA polymerase in E. coliuses
ribonucleotides as substrates and requires ATP as aseparate
energy source.
. Deoxyribonucleoside triphosphates
provide both the substrate and energy required for
polymerisation during replication.
C. The DNA-dependent RNA polymerase is the
main enzyme catalysing DNA replication in E. coli.
D. DNA replication in E. colioccurs at a slow
pace, taking several hours to complete due to its
high accuracy requirements,
169. In a DNA strand the nucleotides are linked together by
A. Glycosidic bonds
A Phosphodiester bonds
C. Peptide bonds
D. Hydrogen bonds.
n
of nitrogen bases of the coding strand of DNAin a
170 If the
sequence
transcription unit is: 5'.
the sequence of bases in its RNA transcript would be
ATGAATG - 3
AUG - 3'
y$- AUG A
UACUU AC - 3
B.5'-
CAUUCAU - 3'
C.5'-
GUAAGUA 3
D. 5' -
sequence of a codon in mRNA is 5' - AUG - 3' the sequence of tRNA pairing with
171. Ifthe base
it must be
ws- UAC - 3'
B.5' - CAU- 3'
C. 5-AUG - 3'
3'
D. 5' - GUA
double helix model?
Howfar is each base pair from the next one in DNA
172.
A. 2 nm
K3.4 nm
C. 34 nm
D. 0.34 nm
173. Synthesis of DNA from RNA is explained by
ACentral dogma reverse
B. Reverse transcription
C. Retroviral replication
D. All of these.
174. Histone proteins are
A. Basic, negatively charged
Basic, positively charged
C. AcidiG, positively charged
D. Acidic, negatively charged
175. The three codons which result in the termination of polypeptide chain synthesis are
A. UAA, UAG, GUA
gUAA, UAG, UGA
C. UAA, UGA, UUA
D. UGU, UAG, UGA
176. Amino acids which are specified by single codons are
A. Phenylalanine and arginine
B. Tryptophan and methionine
C. yaline and proline
. Methionine and arginine.
177.Select the correct match of enzyme with its related function.
A.DNA polymerase - Synthesis of DNA strands
B. Helicase - Unwining of DNA helix
C. Ligase - Joins together short DNA segments
DAll of these
178. Other than DNA polymerase, which are the enzymes involved in DNA synthesis?
A. Topoisomerase
B. Helicase
C. RNA primase
(p.Ah ofthese
179. DNA replication takes place at phase of the cell cycle.
A. G
C. G2
D. M
180. The enzyme DNAdependent RNA polymerase catalyses the polymerisation reaction in
direction.
AOnly 5' ’3'
B. Only 3' ’5'
C. Both (A and (b)
D. None of these
