What is the main difference between modern and classical biotechnology? - CORRECT
ANSWER in modern biotechnology, DNA transfer is possible even between
... [Show More] unrelated organisms
Yeast is one example of a eukaryotic microbe that is extensively used in many industries. What
is a characteristic of yeast but not bacteria? - CORRECT ANSWER 7'-methylguanosine cap is
added to the 5' end of mRNA
What is true of Gram negative bacteria? - CORRECT ANSWER Gram negative bacteria
representatives include pseudomonas and agrobacterium
In the Hershey-Chase experiment on determining the genetic material of phages, which of the
following is true? - CORRECT ANSWER Phage proteins, labeled with radioactive sulfur, ended
up outside of E. coli
In the Avery, McLeod, and McCarthy experiment, they observed that: - CORRECT ANSWER A
non-virulent rough mutant of Streptococcus pneumoniae becomes virulent when mixed with cell
extracts from a virulent smooth strain that was treated....
What is not true of DNA?
A) A single strand of DNA has polarity in that there is a phosphate group at the 3' end and a
hydroxyl group
B) The 5-carbon pentose in DNA is missing an OH in the C2 position
C) The DNA backbone consists of phosphate-sugar, while the rungs are made of paired
nitrogenous bases
D) The paired strands are anti-parallel with one strand going in the 5'-3' direction and the other
going in the 3'-5' direction
E) In complementary base pairing between the two DNA strands, there are 2 H-bonds between A
and T - CORRECT ANSWER A) A single strand of DNA has polarity in that there is a
phosphate group at the 3' end and a hydroxyl group
What does not apply to intrinsic termination?
A) Leads to dissociation of RNA polymerase from the mRNA and template DNA
B) Requires the formation of a hairpin loop near the 3' end of the mRNA
C) A string of UUUUUUs is found at the 5' start of the mRNA
D) Leads to termination of transcription
E) Does not require Rho factor binding to a rut sequence on the 5' portion of nascent mRNA -
CORRECT ANSWER C) A string of UUUUUUs is found at the 5' start of the mRNA
In yeast, post-transcriptional modifications involve the addition of a 5' 7-MeG cap, a 3'polyA
tail, and excision of introns. What is not a function of these RNA processing steps?
A) Facilitate export of mRNA from the cytoplasm to the nucleus
B) Protect the mRNA from degradation by ribonucleases
C) 5' 7-Methyl guanosine cap facilitates attachment of ribosome
D) Contribute to the stability of the mRNAs and increased half life
E) 3' polyA tail enhances translation - CORRECT ANSWER A) Facilitate export of mRNA from
the cytoplasm to the nucleus
What does not apply to translational coupling?
A) Premature termination of translation of the upstream ORF will lead to the downstream ORF
not being translated
B) The upstream ORF possesses a Shine-Dalgarno sequence in its translation initiation region
C) The downstream ORF may be lacking its own start codon.
D) Translational coupling can be used to co-express two recombinant proteins in one mRNA
E) A secondary structure that blocks the start codon of a downstream ORF can be opened up
when an upstream ORF gets translated - CORRECT ANSWER C) The downstream ORF may be
lacking its own start codon
What statement about DNA replication is incorrect?
A) DNA ligase catalyzes phosphodiester bond formation between adjacent Okazaki fragments
B) Replication of the lagging strand is discontinuous
C) "During replication of the lagging strand, DNA synthesis is initiated from multiple primers"
D) "New DNA is synthesized in a 5' to 3' direction, that is, new nucleotides are added to the 3'
end."
E) RNA primers are synthesized by primase during DNA replication
F) "Okazaki fragments are formed only in the leading strand, but not in the lagging strand" -
CORRECT ANSWER F) "Okazaki fragments are formed only in the leading strand, but not in
the lagging strand"
Which property of codons can explain why the same amino acid will be incorporated in a peptide
even if there is a change (mutation) in the nucleotide in the third position of a triplet codon?
A) Ambiguity
B) Codon preference
C) Universal
D) Mutability
E) Redundancy - CORRECT ANSWER E) Redundancy
Post-translational processing does not include:
A) Removal of N-terminal signal peptide in secreted peptides
B) Addition of 5' CAP at the N-terminus
C) "In eukaryotes, glycosylation of secreted proteins"
D) Proteolytic cleavage by peptidases or proteases
E) Removal of N-terminal f-MET or Met. - CORRECT ANSWER B) Addition of 5' CAP at the
N-terminus
"During DNA replication, the enzyme ______________is involved in unwinding the DNA
double helix ahead of the replication fork, while ______________ is the main enzyme that
catalyzes the addition of nucleotides to generate new polynucleotide strands of DNA."
A) Primase: DNA polymerase III
B) DnaA: DNA polymerase III
C) Telomerase: DNA polymerase III
D) Helicase: DNA polymerase III
E) DNA polymerase III : Helicase
F) Topoisomerase: DNA polymerase III - CORRECT ANSWER D) Helicase: DNA polymerase
III
Which statement is incorrect? During translation initiation:
A) IF-2 and IF-3 helps position the mRNA start codon into the P site of the ribosome
B) IF-2 helps guide the f-Met tRNA to the P site
C) IF-3 binds to the 30S ribosomal subunit to promote 30S association with 50S subunit.
D) GTP serves as energy source for the activity of the initiation factors.
E) IF-1 binds to the A site to prevent fMet-tRNA from binding to the A site. - CORRECT
ANSWER C) IF-3 binds to the 30S ribosomal subunit to promote 30S association with 50S
subunit.
"During translation elongation, which component of the ribosome has peptidyl transferase
activity that catalyzes formation of peptide bond between an assembled peptide in the P site to
the incoming amino acid in the A site?"
A) 23S rRNA
B) 16S rRNA
C) EF-Tu
D) 5S rRNA
E) IF-2
F) EF-G - CORRECT ANSWER A) 23S rRNA
What kind of bond holds the nucleotide building blocks of RNAs?
A) Gold bond
B) Amide bond
C) Hydrogen bond
D) Disulfide bond
E) Phosphodiester bond - CORRECT ANSWER E) Phosphodiester bond
What is the significance of the sequences found in -10 and -35 regions of a gene?
A) The DNA sequences that RNA polymerase sigma factor recognize and bind to
B) Site opened up by the ribosomes to initiate translation
C) Site opened up by the ribosomes to initiate transcription
D) Sequences recognized and bound to by RNA polymerase to initiate protein synthesis
E) Site where DNA polymerase opens up the DNA double helix to initiate replication -
CORRECT ANSWER A) The DNA sequences that RNA polymerase sigma factor recognize and
bind to [Show Less]