Review 3 Flashcards
Which statement best describes the ‘semi conservative replication’ of DNA?
In each replication cycle, one of the parental strands is conserved
Which of the following enzymes is not involved in DNA replication?
Reverse transcriptase
The template is read in replication in the-
3’-5’ direction
The prokaryotic DNA chain elongation is carried out by
DNA polymerase III
In a newly synthesized prokaryotic DNA strand, the primers are removed by-
DNA polymerase I
In the genetic disease, Xeroderma pigmentosum, the cells fail to repair the damaged DNA, due to the defect in the-
Nucleotide excision repair
In a segment of DNA exposed to chemicals Cytosine has been deaminated to Uracil, Which of the following mechanisms will remove Uracil and incorporate the
correct base?
Base excision repair
Which of the followings does NOT need a primer in order to function?
RNA polymerase
Which of the followings is required for end to end joining of DNA
DNA ligase
Which of the following enzyme(s) can remove or insert supercoil twists into circular DNA?
Topoisomerases
In which phase of the cell cycle does DNA replication occur?
S
The enzyme responsible for initiating DNA replication in prokaryotes is:
Primase
The enzyme responsible for continuing DNA replication in prokaryotes, once it is initiated is:
DNA polymerase III
Antibiotics such as Ciprofloxacin and Flouroquinolines work by inhibiting a specific enzyme. This enzyme is normally necessary to relieve torsional strain that is caused by the unwinding of the helix. What is the name of this enzyme?
Topoisomerase (DNA Gyrase)
The following are features of DNA replication EXCEPT:
unidirectional
The promoter region in prokaryotic transcription is recognized by?
σ Factor of RNA polymerase
17- Choose the incorrect statement about RNA polymerase?
Can not initiate chain synthesis
The chemical structure of 5’ cap of eukaryotic m RNA cap is？
7- methyl guanosine triphosphate
The prokaryotic RNA chain elongation is carried out by
Core enzyme
Eukaryotic RNA polymerase I is specialized to transcribe which of the following?
Ribosomal RNA
A promoter site on DNA ？
is present upstream to the start site
is present on the coding strand
Initiates transcription
Answer : All of the above
What is added to the 3′-end of many eukaryotic mRNAs after transcription?
Poly A tail
Which of the following does not have introns?
Processed mRNA
Alternative splicing…
Creates different proteins from a single gene
The Rho protein is involved in the _____ stage of transcription.
Termination
The enzyme that accomplishes transcription is termed:
RNA polymerase.
The complimentary messenger RNA strand that would be synthesized from the DNA base sequence of CTGAC would be…
GACUG.
An endonuclease is an enzyme that hydrolyzes:
A phosphodiester bond located in the interior of a polynucleotide
The anticodon region is an important structural component of-
t-RNA
RNA splicing joins together:
two exons.
In protein synthesis which out of the following is not a termination codon?
UUU
A 20 year old man was diagnosed with abnormal form of β – globin (Hemoglobin Constant Spring) which is longer than the normal protein, which of the following point mutation is consistent with the abnormality?
UAA——->CAA
Which one of the following molecules is not a component of the 30 S initiation complex?
ATP
A student is trying to explain the process of protein synthesis. The most accurate summary of the steps would be
DNA makes RNA makes protein
Stop codons
do not code for an amino acid
