MCQOPTIONS
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MCQOPTIONS
This section includes 20 Mcqs, each offering curated multiple-choice questions to sharpen your Cytogenetics knowledge and support exam preparation. Choose a topic below to get started.
| 1. |
Methylated DNA doesn’t form kink as________________ |
| A. | As they don’t fit in the active site |
| B. | The enzyme recognized methylated A as different base than non-methylated A |
| C. | They are less flexible so no kink is formed |
| D. | They don’t interact with the side chains in an active site |
| Answer» E. | |
| 2. |
The Mg2+ ion in restriction endonuclease is not bound to ________ |
| A. | Water molecule |
| B. | Carboxylates of the enzymes aspertate group |
| C. | Oxygen |
| D. | Histidine |
| Answer» E. | |
| 3. |
Restriction enzymes cleave the bond by which type of reaction? |
| A. | SN1 |
| B. | SN2 |
| C. | SE1 |
| D. | SE2 |
| Answer» C. SE1 | |
| 4. |
Which of these restriction enzymes generate 3’ overhang? |
| A. | Sph1 |
| B. | EcoR1 |
| C. | Sma1 |
| D. | Xma1 |
| Answer» B. EcoR1 | |
| 5. |
What does this sequence GC/GGCCGC recognized and cleaves by Not1 Doesn’t agree to? |
| A. | The cleavage is after the 2nd C from 5’ end |
| B. | The cleavage generates a 5’ overhang |
| C. | This sequence has a probability of occurrence in every 1024 bases |
| D. | This cleavage is asymmetric |
| Answer» D. This cleavage is asymmetric | |
| 6. |
WHICH_OF_THESE_RESTRICTION_ENZYMES_GENERATE_3‚ÄÖ√Ñ√∂‚ÀÖ√Ë‚ÀÖ¬•_OVERHANG??$# |
| A. | Sph1 |
| B. | EcoR1 |
| C. | Sma1 |
| D. | Xma1 |
| Answer» B. EcoR1 | |
| 7. |
The Mg2+ ion in restriction endonuclease is not bound to ________$ |
| A. | Water molecule |
| B. | Carboxylates of the enzymes aspertate group |
| C. | Oxygen |
| D. | Histidine |
| Answer» E. | |
| 8. |
Restriction_enzymes_cleave_the_bond_by_which_type_of_reaction?$ |
| A. | S<sub>N</sub>1 |
| B. | S<sub>N</sub>2 |
| C. | S<sub>E</sub>1 |
| D. | S<sub>E</sub>2 |
| Answer» C. S<sub>E</sub>1 | |
| 9. |
A methylated recognition sequence can act as a competitive inhibitor for the restriction endonuclease. |
| A. | True |
| B. | False |
| Answer» B. False | |
| 10. |
Methylated DNA doesn’t form kink as________________$ |
| A. | As they don’t fit in the active site |
| B. | The enzyme recognized methylated A as different base than non-methylated A |
| C. | They are less flexible so no kink is formed |
| D. | They don’t interact with the side chains in an active site |
| Answer» E. | |
| 11. |
When the DNA enzyme interacts with the cognate DNA, there is _______________ |
| A. | Increase in free energy |
| B. | Reduction in free energy |
| C. | Breakdown of the complex |
| D. | Repulsion |
| Answer» C. Breakdown of the complex | |
| 12. |
In EcoRV the enzyme is a ____________ |
| A. | Homo dimer |
| B. | Hetero dimer |
| C. | Trimer |
| D. | Hetero tetramer |
| Answer» B. Hetero dimer | |
| 13. |
Which of the following enzyme air is a neoisoschizomer? |
| A. | SphI and BbuI |
| B. | Not1 and HindIII |
| C. | SmaI and XmaI |
| D. | Pst1 and Sma1 |
| Answer» D. Pst1 and Sma1 | |
| 14. |
In an experiment you introduce your gene of interest in a wild type E. cloli genome using an episome. However, you fail to see the product protein being formed. What could be the possible reason for this? |
| A. | The gene was silenced |
| B. | The gene product was produced in negligible quantity |
| C. | The bacteria was in stress so it was not producing much protein |
| D. | The gene was excised out |
| Answer» E. | |
| 15. |
Which of the sequence will Dcm methylate? |
| A. | GATC |
| B. | GAATC |
| C. | CCGTT |
| D. | CCAGG |
| Answer» E. | |
| 16. |
What does this sequence GC/GGCCGC recognized and cleaves by Not1 Doesn’t agree to?$ |
| A. | The cleavage is after the 2<sup>nd</sup> C from 5’ end |
| B. | The cleavage generates a 5’ overhang |
| C. | This sequence has a probability of occurrence in every 1024 bases |
| D. | This cleavage is asymmetric |
| Answer» D. This cleavage is asymmetric | |
| 17. |
Restriction endonucleases can recognize___________ |
| A. | Tandem repeats |
| B. | Pallindromic sequences |
| C. | GATC |
| D. | No sequence specificity |
| Answer» C. GATC | |
| 18. |
Which of the following is not true about type II restriction endonuclease? |
| A. | Here Clevage and Methylation are by different enzymes |
| B. | In this case the recognition sequence is asymmetric |
| C. | It cleaves within the recognition sequence |
| D. | It can’t cleave at methylated sequences |
| Answer» C. It cleaves within the recognition sequence | |
| 19. |
Which of the following is not true for type 1 restriction endonuclease? |
| A. | It is a single enzyme with 3 subunits |
| B. | Using it is an energy requiring process |
| C. | Methylation and cleavage occurs in the same sequence |
| D. | The cleavage is up to 1000bp away |
| Answer» D. The cleavage is up to 1000bp away | |
| 20. |
Type I restriction endonuclease cuts________________ |
| A. | Within the recognition sequence |
| B. | On either side of the recognition sequence |
| C. | 25 to 30 bp away from the recognition sequence |
| D. | 1000bp away from the recognition sequence |
| Answer» E. | |