Question

Name the selectable markers in the cloning vector pBR322. Mention the role they play.

Answer 1

In the cloning vector pBR322, ampicillin and tetracycline resistance genes serve as selectable markers. They help in the selection of transformed cells from nontransformed cells. They also help distinguish recombinant cells from nonrecombinant cells.

Answer 2

The selectable markers in the cloning vector pBR322 are the genes encoding resistance to antibiotics, specifically ampicillin and tetracycline. These markers play a crucial role in identifying and selecting transformants. When a foreign DNA is inserted into the vector, it disrupts one of the antibiotic resistance genes, often the tetracycline resistance gene. This results in transformants that are resistant to ampicillin but sensitive to tetracycline, allowing selection of recombinant cells. The markers enable growth of only those bacteria that have taken up the plasmid and help distinguish recombinants from non-recombinants through antibiotic sensitivity patterns.