Molecular
Basis of Inheritance
1.
Hershey and Chase experiment with bacteriophage showed that
a)
Protein gets into the bacterial cells
b) DNA is the genetic material
c)
DNA contains radioactive sulphur
d)
Viruses undergo transformation
2.
DNA and RNA are similar with respect to
a)
Thymine as a nitrogen base
b) A
single-stranded helix shape
c) Nucleotide containing sugars, nitrogen bases
and phosphates
d)
The same sequence of nucleotides for the amino acid phenyl alanine
3. A
mRNA molecule is produced by
a)
Replication
b) Transcription
c)
Duplication
d)
Translation
4.
The total number of nitrogenous bases in human genome is estimated to be about
a)
3.5 million
b)
35000
c)
35 million
d) 3.1 billion
5. E.
coli cell grown on 15N medium are transferred to 14N medium and allowed to grow
for two generations. DNA extracted from these cells is ultracentrifuged in a cesium
chloride density gradient. What density distribution of DNA would you expect in
this experiment?
(a)
One high and one low density band.
(b)
One intermediate density band.
(c)
One high and one intermediate density band.
(d) One low and one intermediate density
band.
6.
What is the basis for the difference in the synthesis of the leading and
lagging strand of DNA molecules?
(a)
Origin of replication occurs only at the 5' end of the molecules.
(b)
DNA ligase works only in the 3' → 5' direction.
(c) DNA polymerase can join new nucleotides
only to the 3' end of the growing stand.
(d)
Helicases and single-strand binding proteins that work at the 5' end.
7.
Which of the following is the correct sequence of event with reference to the central
dogma?
(a)
Transcription, Translation, Replication
(b)
Transcription, Replication, Translation
(c)
Duplication, Translation, Transcription
(d) Replication, Transcription,
Translation
8.
Which of the following statements about DNA replication is not correct?
(a)
Unwinding of DNA molecule occurs as hydrogen bonds break.
(b) Replication occurs as each base is paired
with another exactly like it.
(c)
Process is known as semi conservative replication because one old strand is conserved
in the new molecule.
(d)
Complementary base pairs are held together with hydrogen bonds.
9.
Which of the following statements is not true about DNA replication in eukaryotes?
(a)
Replication begins at a single origin of replication.
(b)
Replication is bidirectional from the origins.
(c)
Replication occurs at about 1 million base pairs per minute.
(d) There are numerous different bacterial
chromosomes, with replication ocurring in each at the same time.
10.
The first codon to be deciphered was __________ which codes for ________.
(a)
AAA, proline
(b)
GGG, alanine
(c) UUU, Phenylalanine
(d)TTT,
arginine
11.
Meselson and Stahl’s experiment proved
(a)Transduction
(b) Transformation
(c)
DNA is the genetic material
(d) Semi-conservative nature of DNA replication
12. Ribosomes are composed of two subunits; the smaller subunit of a ribosome has a binding site for _________ and the larger subunit has two binding sites for two __________.
13.
An operon is a:
(a)
Protein that suppresses gene expression
(b)
Protein that accelerates gene expression
(c) Cluster of structural genes with related
function
(d)
Gene that switched other genes on or off
14.
When lactose is present in the culture medium:
(a)
Transcription of lac y, lac z, lac a genes occurs.
(b)
Repressor is unable to bind to the operator.
(c)
Repressor is able to bind to the operator.
(d) Both (a) and (b) are correct.
15.
The association of histone H1 with a nucleosome indicates
a)
Transcription is occurring
b)
DNA replication is occurring
c) The DNA is condensed into chromatin
fibre
d)
The DNA double helix is exposed
16.
Which of the following is not required for any of the techniques of DNA fingerprinting
available at present?
a) Zinc finger analysis
b)
Restriction enzymes
c)
DNA-DNA hybridization
d)
polymerase chain reaction
17.
Satellite DNA is important because it
a)
codes for proteins needs in cell cycle
b) shows high degree of polymorphism in
population and also the same degree of polymorphism in an individual, which is
heritable from parents to children
c)
Does not code for protein and is same in all members of the population.
d)
Codes for enzymes needed for DNA replication.
18.
The diagram shows an important concept in the genetic implication of DNA. Fill
in the blanks A to C.
A B C
DNA
----→mRNA ---------→protein -proposed by---
a)
A- transcription, B- replication C-James Watson
b)
A- transcription, B- transcription, C-Erwin
c) A- transcription, B- translation,
C-Francis Crick
d)
A- transcription, B- extension, C-Rosalind Frankin
19.
Select the two statements out of the four (I –IV) given below about lac operon.
i.
Glucose or galactose may bind with the repressor and inactive it.
ii. In the absence of lactose, the repressor binds with
the operator region
iii.
The z-gene codes for permease.
iv. This was elucidated by Francois Jacob and Jacques
monod.
The
correct statements are
a) i
and ii
b) i
and iii
c) ii and iv
d) i
and ii
20.
Which one of the following pairs of codons is correctly matched with their
function or the single for the particular amino acid?
a)
GUU, GCU – Alanine
b) UAG, UGA – Stop codon
c)
AUG, ACG - start/methionine
d)
UUA, UCA – Leucine
21.
During translation initiation in prokaryotes, a GTP molecules is needed in
a) association of 30s, mRNA with formyl
met tRNA
b)
association of 50s subunit of ribosome with initiation complex
c)
formation of formyl met tRNA
d)
binding of 30s subunit of ribosome with mRNA.
22.
Reverse transcriptase is
a)
RNA dependent RNA polymerase
b)
DNA dependent RNA polymerase
c)
DNA dependent DNA polymerase
d) RNA dependent DNA polymerase
23. Escherichia
coli fully labeled with N14 medium. The two strands of DNA molecules of the
first generation bacteria have
a)
Different density and do not resemble parent DNA
b) Different density but resemble parent
DNA
c)
Same density and resemble parent DNA
d)
Same density but do not resemble parents DNA
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