NEET : Multiple Choice questions: DNA Replication


1. Who of the following proposed the mechanism of central dogma in molecular biology . 

A. Fredrick Griffith 
B. Wilkins and Franklin 
C. Hershey and Chase 
D. Francis Crick 
Answer: D Explanation 

2. Central dogma in molecular biology explain the flow of genetic information from DNA to
A. DNA - mRNA - Protein
B. Protein -mRNA - DNA
C. Protein - DNA - mRNA
D. DNA - Protein - mRNA
Answer: D Explanation

3. The flow of genetic information from DNA to DNA is called 
A. Transduction
B. Translation
C. Replication 
D. Transcription
Answer: C Explanation

4. Given below are two statements and select the correct option
Statement I : During Replication, the genetic information is copied from DNA to DNA.
Statement Il : Replication is high energy process therefore DNA helix  is opened completely.
A. Statement l is true and statement ll is false.
B. Statement l is false and statement ll is true.
C. Both statement I and II is true.
D. Both statement I and II is false.
Answer: A Explanation

5. Consider the following sentences give below  and select the number of correct statement.
1. During replication, Both strands of DNA strand are opened with the help of helicase enzyme.
2. Replication is high energy process therefore DNA helix  is  not opened completely to conserve the energy.
3. After unwinding, DNA helix assume Y shaped structure called replication fork.
4. The position at DNA helix from where opening occurs called origin of replication or ori.
A. One B. Two
C. Three D. Four
Answer: D Explanation

6. Which  one of the following is the first step of DNA replication.
A. Formation of replication fork 
B. Creation of origin of replication ( Ori)
C. Unwinding of DNA helix.
D. Stability of DNA Strands.
Answer: C Explanation

7. Which  one of the following enzyme is participated in opening of DNA Helix.
A. DNA Helicase 
B. DNA Polymerase 
C. DNA Ligase
D. RNA Polymerase 
Answer: A Explanation

8. Which  one of the following step is followed  by the unwinding of DNA helix.
A. Primer is formed at 5' end  of strand with polarity from 5' to 3'
B. Primer is formed at 3' end  of strand with polarity from 5' to 3'
C. Primer is formed at 5' end  of strand with polarity from 3' to 5'
D. Primer is formed at 3' end of strand with polarity from 3' to 5'
Answer: D Explanation

9. Which  one of the following statement is incorrect about the primer formed during the replication.
A. This primer is formed of RNA Polymerase.
B. It is formed at 3' end of strand with polarity 3' to 5'.
C. This primer is extended by the enzyme Helicase.
D. Primer is responsible to synthesized new strand of DNA during replication.
Answer: C Explanation

10. Which  one of the following enzyme extends the primer in length or catalyze the  polymerisation of nucleotides of new strand of DNA.
A. DNA Helicase 
B. DNA Polymerase 
C. DNA Ligase
D. RNA Polymerase 
Answer: B Explanation

11. Consider the following statement and select the correct code.
1. DNA polymerase catalyze the polymerisation of nucleotides in continue manner on strand with polarity 3' to 5' hence called continuous strand.

2. DNA polymerase catalyze the polymerisation of nucleotides in form of fragments  on strand with polarity 5' to 3' hence called discontinuous strand.
A. Only 1
B. Only 2
C. Both 1 and 2
D. Neither 1 nor 2
Answer: C Explanation

12. DNA Polymerase can polymerised the what number of nucleotides.
A. 20000 base pair per second 
B. 200000 base pair per second
C. 2000 base pair per second 
D. 200 base pair per second 
Answer : C Explanation

13. The fragments that are formed on strand with polarity 5' to 3' during polymerisation of nucleotides called as 
A. VNTR           B. Probe
C. Okazaki       D.SNIP
Answer : C Explanation

14. Later on , Okazaki fragments are joined by which enzyme to make Strand complete.
A. DNA Helicase 
B. DNA Polymerase 
C. DNA Ligase
D. RNA Polymerase 
Answer: C Explanation

15. Which of the following statement is incorrect.
A. DNA Strand with polarity 3' to 5' is continuous strand.
B.okazaki fragments are formed on continuous strand.
C.DNA replication is semiconservative in nature because  in a newly formed DNA molecule one strand is old and another strand is new.
D. Replication takes place in nucleus of Eukaryotic and cytoplasm of Prokaryotic cell.
Answer : B Explanation

15. At which phase of cell cycle , replication takes place.
A. G1 phase
B. G2 phase
C. S phase
D. M phase
Answer : C Explanation

16. Diring replication, Which one of the following act as substrate and used as a source of energy.
A. Triosephosphate
B. Guanosine triphosphate 
C. Nucleoside triphosphate 
D. Deoxyribonucleoside triphosphate
Answer : D Explanation



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