Why is a single-stranded,circular DNA an ineffective template for DNA polymerase?
A)It has a 3'-hydroxyl group,but lacks a template.
B)It lacks a 3'-hydroxyl group,but has a template.
C)It lacks a 3'-hydroxyl group and a template.
D)It has a 3'-hydroxyl group and has a template.
E)It lacks a 5'-hydroxyl group and has a template.

Question

Quizplus · Accepted Answer

DNA polymerase requires a 3'-hydroxyl group on the template strand to add nucleotides to the growing strand. In a single-stranded, circular DNA, there is a template strand but no 3'-hydroxyl group available for DNA polymerase to add the nucleotides. Hence, it is an ineffective template for DNA polymerase.

Why Is a Single-Stranded,circular DNA an Ineffective Template for DNA