Question

Which of the following would happen if you restriction digested a vector at exactly two Restriction Sites?

(A) 2 fragments form
(B) The Vector is linearized and 2 fragments form
(C) The vector is linearized as 1 fragment.
(D) None of the above.

Answer 1

When a circular vector is restriction digested at exactly two restriction sites, it will be linearized to form one linear DNA fragment, not two separate fragments.

Step-by-step explanation:

If you restriction digest a vector at exactly two restriction sites, the outcome would depend on the configuration of the vector and the cuts made by the restriction enzyme. Restriction enzymes recognize specific DNA sequences, called restriction sites, and make cuts at these locations. Depending on the specific restriction enzyme, the cuts can produce either sticky ends or blunt ends. Plasmids, which are commonly used as vectors in recombinant DNA technology, are usually circular DNA molecules.

When a circular vector is digested at two restriction sites, it will be linearized, resulting in one linear fragment of DNA. Therefore, if exactly two cuts are made, the vector opens up, but since it was originally circular, you end up with one contiguous piece of linear DNA. No separate fragments are created in the process unless there are additional cuts.

So the correct answer is: (C) The vector is linearized as 1 fragment.