A gene sequence is cut at a restriction site and DNA polymerase is then used to make the single-stranded regions of the sticky ends into double-stranded DNA. The ends of the altered DNA are then ligated back together. What is the effect on the gene sequence?
A)Its amino acids remain constant
B)The reading frame of the gene is destroyed.
C)The gene is unchanged.
D)The gene is transposed.
E)The gene is inverted.

Question

Quizplus · Accepted Answer

The reading frame of the gene is destroyed because the restriction enzyme cuts the DNA at a specific sequence, and the DNA polymerase then adds nucleotides to the sticky ends to create double-stranded DNA. However, the DNA polymerase does not know the correct reading frame for the gene, so it may add nucleotides in a way that disrupts the reading frame. This can cause the gene to produce a non-functional protein.

A Gene Sequence Is Cut at a Restriction Site and DNA