Question

Question: Explain why a cloning vector usually includes a selectable marker.

Short answer

Answer

The cloning vector includes a selectable marker as it eliminates the non-transformants in the cloning vector.

Step-by-step solution

Cloning vector

A cloning vector is a short sequence of DNA that may be kept in an organism for a long time and into which a foreign DNA fragment can be introduced for cloning.

The cloning vector includes a selectable marker

Antibiotic resistance genes are selectable markers.They aid in the identification of transformants and assist in selectively promoting their growth while eradicating non-transformants in the cloning vector.

Hence, the cloning vector usually includes a selectable marker so that it eliminates the non- transformants which are present in the cloning vector.