Translation and Regulation
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Which
phage always carries a small piece of E.coli genome?
a. T3
b. Mu
c. Lambda
d. T4
Which
binding is inhibited by pactamycin?
a. Formation
of peptide bond in P site
b. Aminoacyl-tRNA
to the A-site of 30S subunit
c. Initiator-tRNA to 30S/40S initiation
complexes
d. Peptidyl
t-RNA to the 50S subunit
The
final step of gene expression is protein synthesis, which is also known as
_____________.
a. translation
b. replication
c. none
of these
d. transcription
Three
stop codons, which aids in termination of translation are also known as
_____________.
a. missense
codons
b. nonsense codons
c. antisense
codons
d. pause
codons
The
ribosome binding site _____________.
a. is located immediately upstream of the
start codon
b. is located
upstream of the promoter sequence
c. is
more likely to be associated with an operon than with a gene encoding a single
protein
d. forms
a stem-loop structure in the RNA
Which
of the following molecule catalyzes the transpeptidation reaction?
a. Peptidyl transferase
b. RNA
polymerase
c. DNA
polymerase
d. DNA
ligase
Which
of the termination codon is called amber?
a. UAA
b. UAG
c. UGA
d. AUG
Which
of the following is a nontranslated sequence located between the transcription
and the translation start site?
a. Ending
frame
b. Leader sequence
c. Trailer
sequence
d. Reading
frame
What
is the maximum number of different amino acids in a polypeptide chain coded by
the synthetic polyribonucleotides (UCAG)5?
a. Four
b. Three
c. One
d. Two
Negative
regulation of protein synthesis is accomplished by _____________.
a. the binding of a repressor to the DNA
b. the
binding of RNA polymerase to the promoter
c. the
binding of a repressor to the RNA polymerase
d. allosteric
inhibition
Site
in the ribosome from which the tRNA donates amino acids to the growing
polypeptide chain is _____________.
a. O
site
b. A
site
c. P site
When
was the genetic code completed?
a. 1968
b. 1966
c. 1952
d. 1958
Which
stop codon has been found to encode selenocysteine?
a. UAG
b. UAA
c. AGA
d. UGA
What
is the direct cause of cell death by diphtheria toxin?
a. Inactivation of a translational elongation
factor
b. Induction
of apoptosis
c. None
of the above
d. Formation
of an ion channel in the cell membrane
The development
of global regulatory systems in prokaryotes _____________.
a. determines
the exact location of the replication site
b. regulates many genes under varying
environmental conditions
c. aids
in DNA replication
d. determines
the exact location of the cell on the globe
The
interaction between the mRNA and tRNA determined the position of amino acid in
a polypeptide sequence. This is called the _____________.
a. promiscuity
b. Wobble
hypothesis
c. stagerivity
d. adaptor hypothesis
What
are the Svedberg values for the subunits of the 70S ribosomes of E. colli?
a. 40S
and 30S
b. 50S and 30S
c. 50S
and 20S
d. 40S
and 20S
Which
of the following three codons translate as serine (Ser)?
a. AUG
b. AGU
c. CGA
d. CAU
The
role of molecular chaperones is to _____________.
a. facilitate
binding of RNA polymerase to DNA
b. facilitate
binding of ribosomes to mRNA
c. aid a newly synthesized polypeptide in
folding to its proper shape
d. degrade
newly synthesized polypeptides that contain inaccurate sequences
What
is the action of tetracycline in prokaryotes?
a. It
blocks peptidyl transferase reaction on ribosomes
b. It
blocks translocation reaction on ribosomes
c. Not
known with certainity
d. It blocks the binding of amino-acyl tRNA
to the A site of ribosomes
A quorum
sensing system _____________.
a. consists
of a sensor component that phosphorylates a regulatory protein
b. detects
a signal from the external environment
c. controls
the activity of ribosomes directly
d. senses a compound produced by the
bacterium itself
The
Shine-Dalgarno sequence is _____________.
a. a short sequence that acts as a ribosomal
binding site
b. trailer
sequence
c. the
reading frame of a gene
d. a
stop codon
Which
of the following statement is correct?
a. Restriction
fragment length polymorphism (RFLP) is usually formed in coding sequence of a
gene
b. The
size and sequence of introns can be deduced from the cDNA sequence
c. Restriction
endonuclease can cleave ss and dsDNA both
d. Amino acid sequence of a protein can be
deduced from corresponding cDNA nucleotide
What
was the first bacterial genome to be sequenced and made public?
a. Haemophilus influenzae
b. Bacillus
subtilis
c. Escherichia
coli
d. No
bacterial genome has been sequenced yet
Which
of the following modified amino acid is used at the starting of most
prokaryotic proteins?
a. N-formylmethionine
b. N-formylserine
c. N-formylalanine
d. N-formylleucine
During
amino acid activation a(n) _____________.
a. methyl
group is attached to rRNA
b. amino
acid is bound to mRNA
c. methyl
group is attached to an amino acid
d. amino acid is bound to tRNA
The
nonsense codon(s) is/are _____________.
a. UGA
b. UAA
c. all of these
d. UAG
Which
of the following defines an open reading frame (ORF)?
a. A
plasmid vector used in genome sequencing
b. The
sequence of a complete genome
c. A
sequence of genome in bacteriophage
d. A possible gene predicted by DNA
sequencing
Which
of the following act as the blueprint or template for the process of protein
synthesis that takes place on ribosomes?
a. tRNA
b. DNA
c. mRNA
d. rRNA