MCQOPTIONS
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MCQOPTIONS
This section includes 25 Mcqs, each offering curated multiple-choice questions to sharpen your DNA Replication knowledge and support exam preparation. Choose a topic below to get started.
| 1. |
Eukaryotes differ from prokaryote in mechanism of DNA replication due to ____________ |
| 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. | Unidirectional rather than semi-discontinuous replication |
| Answer» D. Unidirectional rather than semi-discontinuous replication | |
| 2. |
Semi-conservative DNA replication was first demonstrated in ____________ |
| A. | Drosophila melanogaster |
| B. | Escherichia coli |
| C. | Streptococcus pneumonae |
| D. | Drosophila melanogaster |
| Answer» B. Escherichia coli | |
| 3. |
What is a mode of replication in E.coli? |
| A. | Intermediate |
| B. | Dispersive |
| C. | Conservative |
| D. | Semiconservative |
| Answer» E. | |
| 4. |
What is DNA replication? |
| A. | Conservative |
| B. | Non-conservative |
| C. | Semi-conservative |
| D. | None of the mentioned |
| Answer» D. None of the mentioned | |
| 5. |
Double-helix structure of DNA is discovered by___________ |
| A. | Gobind Khurana |
| B. | Nirenberg |
| C. | Watson and Crick |
| D. | Darwin |
| Answer» D. Darwin | |
| 6. |
Base sequence of each parental strand considered to synthesis new complementary strand. |
| A. | True |
| B. | False |
| Answer» B. False | |
| 7. |
Which enzyme used to join bits of DNA? |
| A. | DNA polymerase |
| B. | DNA ligase |
| C. | Endonuclease |
| D. | Primase |
| Answer» C. Endonuclease | |
| 8. |
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» D. None of the mentioned | |
| 9. |
Which of the following is true about DNA polymerase? |
| 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» B. It can synthesize DNA in the 3 to 5 direction | |
| 10. |
What is the reaction in DNA replication catalyzed by DNA ligase? |
| A. | Addition of new nucleotides to the leading strand |
| B. | Addition of new nucleotide to the lagging strand |
| C. | Formation of a phosphodiester bond between the 3 -OH of one Okazaki fragment and the 5 -phosphate of the next on the lagging strand |
| D. | Base pairing of the template and the newly formed DNA strand |
| Answer» D. Base pairing of the template and the newly formed DNA strand | |
| 11. |
DNA unwinding is done by ____________ |
| A. | Ligase |
| B. | Helicase |
| C. | Topoisomerase |
| D. | Hexonuclease |
| Answer» C. Topoisomerase | |
| 12. |
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» E. | |
| 13. |
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» C. 3 to 5 endonuclease activity | |
| 14. |
Replication in E. coli is initiated by the generation of short RNA primers using |
| A. | RNA polymerase |
| B. | primase |
| C. | reverse transcriptase |
| D. | both (a) and (b) |
| Answer» E. | |
| 15. |
The melting of 40-45 bp at the oriC site of E. coli requires |
| A. | DNA + ATP + HU |
| B. | DNA + ATP + HU + DNAb |
| C. | DNA+ ATP + HU + DNAb + DNAa |
| D. | DNA + ATP + HU + DNAb + DNAa + Pol III holoenzyme |
| Answer» B. DNA + ATP + HU + DNAb | |
| 16. |
DNA gyrase in E. coli |
| A. | adds positive supercoils to chromosomal DNA |
| B. | can be inhibited with antibiotics |
| C. | is required only at the oriC site |
| D. | performs the same function as helicase in eukaryotes |
| Answer» C. is required only at the oriC site | |
| 17. |
Name the protein, which is responsible for the formation of RNA primer? |
| A. | Topoisomerase |
| B. | Gyrase |
| C. | Helicase |
| D. | Primase |
| Answer» E. | |
| 18. |
Which of the following would relax negatively supercoiled DNA? |
| A. | DNA gyrase |
| B. | Type I topoisomerase |
| C. | Collagen |
| D. | Elastin |
| Answer» C. Collagen | |
| 19. |
Name the protein, which is used for termination of replication? |
| A. | DnaC |
| B. | SSB |
| C. | Tus protein |
| D. | DNA polymerase |
| Answer» D. DNA polymerase | |
| 20. |
Which of the following protein does not involve in the initiation of replication? |
| A. | DnaA |
| B. | SSB (Single strand binding protein) |
| C. | DnaB |
| D. | DnaF |
| Answer» E. | |
| 21. |
Which of the following protein is required for connecting Okazaki fragments? |
| A. | Scaffold protein |
| B. | Helicase |
| C. | Primase |
| D. | DNA gyrase |
| Answer» E. | |
| 22. |
How many numbers of replicon is found in E.coli? |
| A. | Five replicon |
| B. | Two replicon |
| C. | Single replicon |
| D. | Multiple replicon |
| Answer» D. Multiple replicon | |
| 23. |
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» B. Site which prevents initiation | |
| 24. |
What is the approximate size (in kb) of the E. coli genome? |
| A. | 3000 kilobase |
| B. | 4500 kilobase |
| C. | 5500 kilobase |
| D. | 6500 kilobase |
| Answer» C. 5500 kilobase | |
| 25. |
E.coli DNA polymerases II and III lack |
| A. | 5' 3' exonuclease activity |
| B. | 5' 3' endonuclease activity |
| C. | partially 5' 3' exonuclease activity |
| D. | partially 5' 3' endonuclease activity |
| Answer» B. 5' 3' endonuclease activity | |