Question

A gene whose expression helps to identify transformed cell is known as :

• A. Vector
• B. Plasmid
• C. Structural gene
• D. Selectable marker

Answer 1

The Correct Option is D

In recombinant DNA technology, selectable markers helps in identifying and eliminating non-transformants and selectively permitting the growth of the transformants.

Answer 2

In recombinant DNA technology, a selectable marker is a gene that allows scientists to identify cells that have successfully taken up foreign DNA (transformation).

• These marker genes typically encode for antibiotic resistance. For instance, a plasmid might contain a gene for ampicillin resistance.
• After introducing the plasmid containing the foreign DNA and the selectable marker into a culture of cells, scientists can add the antibiotic ampicillin to the culture medium.
• Only the cells that have taken up the plasmid and the selectable marker gene will survive because they will be resistant to the antibiotic.

Thus, the right answer to this question is a selectable marker.