MCQ on DNA Replication with Answers Pdf

MCQ Questions on DNA Replication with Answers

Here below we listed Replication MCQ with Answers Pdf Gear up for your Exam Preparation with top and good Multiple Choice Questions on DNA Replication that are also recommended by toppers, making it easier for you to score more in Exam.


Important Points to Remember about DNA :

  1. Replication is the process in which a double-stranded DNA molecule is replicate to produce its identical DNA molecules is called DNA replication.
  2. DNA replication occurs in the cytoplasm of prokaryotes and in the nucleus of eukaryotes.
  3. Various Enzymes are required for DNA replication since they catalyze very important steps in the process.
  4. The Process of DNA replication is extremely important for cell growth and reproduction in organisms. It is also vital in the cell repair process.
  5. In bacteria such as E. coli, polymerase III is the main replication enzyme, while polymerase I, II, IV and V are responsible for Proofreading Mechanism.
  6. In Drosophila melanogaster the Semi-conservative DNA replication was firstly demonstrated. Generally E.coli bacteria  is used for Replication Studies.
  7. DNA polymerase synthesizes DNA in 5’ to 3’ direction. Helicase enzymes separates the two strands of DNA during replication. Topoisomerase enzymes remove supercoiling in replicating DNA ahead of the replication fork.
  8. 3’ to 5’ exonuclease activity is required for proofreading during DNA replication by DNA polymerase III.
  9. In eukaryotes DNA polymerase gamma is required for mitochondrial DNA replication. 
  10. In some viruses DNA is synthesized from RNA by the enzyme Reverse transcriptase ..
MCQ on DNA Replication


MCQ on DNA Replication ( DNA Synthesis) :

1. In which of the following organisms the Semi-conservative DNA replication was first demonstrated____________

(a) Drosophila melanogaster

(b) Escherichia coli

(c) Streptococcus pneumonae

(d) Drosophila melanogaster

Answer: A


2. Which of the following bacteria is used for DNA replication studies?

(a) Neurospora crassa

(b) Drosophila melanogaster

(c) Escherichia coli

(d) Pneumococcus

Answer: C


3. Eukaryotic Organisms differ from prokaryotic organisms in mechanism of DNA replication due to the____________

(a) Use of DNA primer rather than RNA primer

(b) Different enzyme for synthesis of lagging and leading strand

(c) Discontinuous rather than semi-discontinuous replication

(d) None of the above 

Answer: C


4. What is the origin of replication?

(a) Particular site at which DNA replication starts

(b) Site which prevents initiation

(c) Random location on the DNA

(d) Site at which replication terminated

Answer: A


5. Which of the following enzymes separates the two strands of DNA during replication?

(a) Gyrase

(b) Topoisomerase

(c) Helicase

(d) DNA polymerase

Answer: C


6. Which of the following enzymes remove supercoiling in replicating DNA ahead of the replication fork?

(a) DNA polymerases

(b) Helicases

(c) Primases

(d) Topoisomerases

Answer: D


7. DNA replication is__________

(a) conservative

(b) conservative and discontinuous

(c) semi-conservative and discontinuous

(d) semi-conservative and semi-discontinuous

Answer: D


8. Which of the following reactions is required for proofreading during DNA replication by DNA polymerase III?

(a) 5’ to 3’ exonuclease activity

(b) 3’ to 5’ exonuclease activity

(c) 3’ to 5’ endonuclease activity

(d) 5’ to 3’ endonuclease activity

Answer: B


9. Termination of replication is triggered by_________

(a) DNA polymerase

(b) Helicase

(c) SSB

(d) Tus protein

Answer: D


10. DNA unwinding is done by____________

(a) Ligase

(b) Helicase

(c) Topoisomerase

(d) Hexonuclease

Answer: B


11. DNA polymerase synthesizes__________

(a) DNA in 5’-3’ direction

(b) DNA in 3’-5’ direction

(c) mRNA in 3’-5’ direction

(d) mRNA in 5’-3’ direction

Answer: A


12. Which of the following statement is true about DNA polymerase enzyme?

(a) It can synthesize DNA in the 5’ to 3’ direction

(b) It can synthesize DNA in the 3’ to 5’ direction

(c) It can synthesize mRNA in the 3’ to 5’ direction

(d) It can synthesize mRNA in the 5’ to 3’ direction

Answer: A


13. What is a mode of replication in E.coli?

(a) Intermediate

(b) Dispersive

(c) Conservative

(d) Semiconservative

Answer: D


14. The fragments of DNA are joined together by which of the following enzymes?

(a) Endonuclease

(b) DNA polymerase

(c) Primase

(d) Ligase

Answer: D


15. How many numbers of replicon is found in E.coli?

(a) Five replicon

(b) Two replicon

(c) Single replicon

(d) Multiple replicon

Answer: C


16. How many numbers of replicon is found in Eukaryotes?

(a) Five replicon

(b) Two replicon

(c) Single replicon

(d) Multiple replicon

Answer 


17. In eukaryotes, which of the following DNA polymerase is required for mitochondrial DNA replication?

(a) DNA Polymerase alpha

(b) DNA Polymerase beta

(c) DNA Polymerase gamma

(d) DNA Polymerase delta

Answer: C


18. Which of the following enzymes is the principal replication enzyme in E. coli?

(a) DNA polymerase I

(b) DNA polymerase II

(c) DNA polymerase III

(d) None of the mentioned

Answer: C


19. In some viruses DNA is synthesized from RNA by the enzyme_____________

(a) DNA synthetase

(b) DNA polymerase

(c) Reverse transcriptase

(d) RNA Polymerase 

Answer: C


20. DNA polymerase III holoenzyme possesses the________

(a) polymerase activity only

(b) 3’→ 5’ endonuclease activity

(c) 3’→ 5’ exonuclease activity and polymerase activities

(d) 5’→ 3’ exonuclease activity

Answer: C


21. DNA replication is bidirectional and anti-parallel. Which of the statement is FALSE regarding the DNA replication?

(a) The DNA synthesis i.e. addition of nucleotide occurs from 5'-3' position

(b) The DNA synthesis is semi-continuous with continuous leading strand and discontinuous lagging strand.

(c) The synthesis of leading and lagging strands occurs simultaneously

(d) None of the Above

Answer: D


22. Which of the followings are the characteristic feature of DNA replication______________

(a) DNA replication requires Semi conservative and Bidirectional 

(b) DNA replication requires short RNA primers

(c) DNA replication is a highly accurate process

(d) All of the Above

Answer: D


23. The Chargaff rules state that the number of purines and pyrimidines are equal (A+G = T + C) in any double-stranded DNA molecules. Watson and Crick later solved the structure of DNA and nitrogen base pairings. Which of the following base pairing rule is true______

(a) Adenine pairs with Guanine and Thymine pairs with Cytosine

(b) Adenine pairs with Thymine and Guanine pairs with Cytosine

(c) Adenine pairs with Cytosine and Guanine pairs with Thymine

(d) DNA base pairing is nonspecific

Answer: B


24. Which enzyme is responsible for removing the RNA primers added during DNA replication? 

(a) Primase

(b) DNA ligase

(c) DNA polymerase I

(d) DNA polymerase III

Answer: C


25. What is the role of topoisomerases in eukaryotic DNA replication?

(a) Topoisomerise enzymes cut, uncoil and reseal the double stranded DNA

(b) Topoisomerise enzymes bind to the origin of replication sites within double stranded DNA

(c) Topoisomerise enzymes open up the double stranded DNA at the replication fork

(d) Topoisomerise enzymes join the Okazaki fragments together with phosphodietster bonds

Answer: A


26. DNA replication occurs in which phase of cell cycle?

a) Mitosis

b) Prophase

c) Interphase

d) Metaphase

Answer: C


27. DNA replication takes place in__________

(a) G0 Phase

(b) G1 Phase

(c) G2 Phase

(d) S Phase

Answer: D


NEET Related Articles  :