Read the following passage and answer the questions that follow :
We know that plasmids and bacteriophages are the most commonly used vectors in biotechnology experiments. If we can link an alien piece of DNA to the plasmid DNA, the alien DNA can be multiplied equal to the copy number of the plasmid. Engineered vectors are used these days. Study the diagram of the E. coli cloning vector pBR322 and answer the questions that follow :
(b) (ii) Identify and name two selectable markers shown in the diagram.
Show Hint
Selectable markers in pBR322 are antibiotic resistance genes.
Step 1: What a selectable marker is:
A selectable marker is a gene that lets us pick out the host cells which took up the vector.
In pBR322 these are antibiotic resistance genes.
Step 2: Name the markers:
One marker is ampR, the gene for ampicillin resistance.
The other marker is tetR, the gene for tetracycline resistance.
These are the two gene segments marked G and H on the inner ring of the diagram.
Final Answer:
The two selectable markers are ampR (ampicillin resistance) and tetR (tetracycline resistance).
