MCQOPTIONS
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MCQOPTIONS
This section includes 12 Mcqs, each offering curated multiple-choice questions to sharpen your Cytogenetics knowledge and support exam preparation. Choose a topic below to get started.
| 1. |
If a bacteria is facing lack of carbon sources in the media, which sigma factor concentration is expected to increase? |
| A. | Sigma E |
| B. | Sigma S |
| C. | Sigma 70 |
| D. | Sigma 32 |
| Answer» C. Sigma 70 | |
| 2. |
You artificially increase the level of 32 in an E. coli culture. What will you expect to see? |
| A. | rpo H transcription permanently inhibited |
| B. | cdc transcription constitutively turned on |
| C. | rpo H temporarily activated |
| D. | cdc 6 permanently turned off |
| Answer» D. cdc 6 permanently turned off | |
| 3. |
Which sigma factor is bound to Rse A? |
| A. | <sup>D</sup> |
| B. | <sup>G</sup> |
| C. | <sup>F</sup> |
| D. | <sup>E</sup> |
| Answer» E. | |
| 4. |
Which DNA binding domain is seen in region 4.2 of sigma factor? |
| A. | Zinc fingers |
| B. | Helix turn helix |
| C. | Leucine zipper |
| D. | Beta barrel |
| Answer» C. Leucine zipper | |
| 5. |
We know that region 2.4 of sigma factor binds DNA at -10box. What is the function of 2.1? |
| A. | It is a flexible loop with no known function |
| B. | It binds -35box |
| C. | It binds RNA polymerase |
| D. | It binds region 4.1 to give sigma its specific structure and function |
| Answer» D. It binds region 4.1 to give sigma its specific structure and function | |
| 6. |
Loosening the binding between polymerase and non-specific site is important to confer higher specificity. In Bacillus subtilis what is responsible for this action? |
| A. | Sigma factor |
| B. | Alpha subunit |
| C. | Beta subunit |
| D. | Delta subunit |
| Answer» E. | |
| 7. |
What is the function of 1st subunit of sigma factor in 70 and 43? |
| A. | It helps to bind sigma to DNA |
| B. | It helps to bind sigma to core beta subunit |
| C. | It helps to bind sigma to core alpha subunit |
| D. | It prevents sigma to bind to DNA |
| Answer» E. | |
| 8. |
Which is the primary sigma factor in Bacillus subtilis? |
| A. | <sup>70</sup> |
| B. | <sup>43</sup> |
| C. | <sup>35</sup> |
| D. | <sup>32</sup> |
| Answer» C. <sup>35</sup> | |
| 9. |
In an experiment you wrongly added Rifampicin antibiotic to Rifampicin sensitive bacteria. You try to correct your mistake by adding more core subunits (resistant to Rifampicin) to your mixture. What would you expect to see? |
| A. | Normal transcription to restart |
| B. | Transcription will restart but it will be non-specific as you added core enzyme |
| C. | Impaired transcription with more abortive transcripts |
| D. | No transcription |
| Answer» B. Transcription will restart but it will be non-specific as you added core enzyme | |
| 10. |
When sigma subunit dissociates from the RNA polymerase what happens to the DNA binding clamp of the core? |
| A. | It opens again |
| B. | It closes again |
| C. | It enters a semi open stage |
| D. | It is phophorylated and ubiquitination occurs |
| Answer» E. | |
| 11. |
You transcribe a gene and obtain mRNA. To detect which strand is transcribed you replicate each strand in vitro and use the newly synthesized strand for hybridization with mRNA. If mRNA hybridize with the newly replicated strand from 1st strand then the gene transcribed was in ________ |
| A. | 1<sup>st</sup> strand |
| B. | 2<sup>nd</sup> strand |
| C. | Same copy in both strands |
| D. | Dispersed |
| Answer» C. Same copy in both strands | |
| 12. |
If you study T4 bacteriophage transcription with holoenzyme which genes will you expect to be transcribed? |
| A. | Immediate early |
| B. | Early |
| C. | Delayed |
| D. | Late |
| Answer» B. Early | |