Which of the following would NOT be a useful selectable marker?
1. | A gene encoding a protein that degrades the antibiotic ampicillin. |
2. | A gene encoding a protein that allows the cell to synthesize histidine. |
3. | A gene encoding a protein that is an essential structural component of the cell. |
4. | All of these are useful selectable markers. |
You are inserting your gene of interest into the Lac Z gene in a plasmid also containing a tetracycline-resistant gene. You plate your transformed bacteria on media containing tetracycline and X-gal. Which of the following results would indicate a clone with recombinant plasmids?
1. | A clone which did not grow on the tetracycline plates |
2. | A white colony on the tetracycline plates |
3. | A blue colony on the tetracycline plates |
4. | A red colony on the tetracycline plates |
Consider the following statements:
I: | Ori is responsible for the copy number of the linked DNA. |
II: | Transformation is a process through which a piece of DNA is introduced into a host bacterium. |
III: | Bacteriophages have very high copy numbers of their genome within the bacterial cell. |
Which of the above statements are true?
1. | I and II only | 2. | I and III only |
3. | II and III only | 4. | I, II, and III |