Which of the following is a reason why sticky end producing restriction enzymes are preferred compared to blunt end ones?

a) because sticky ends created by any restriction enzymes can be ligated to sticky ends created by any other restriction enzyme.
b) because sticky ends are more amenable to the mechanism of phosphodiester bond formation by dna ligase.
c) because blunt ends can be mistaken as double stranded breaks which are degraded by dna repair pathways.
d) because sticky ends can be temporarily held together by hydrogen bonding between the two strands.
e) because blunt ends can be temporarily held together by hydrogen bonding between the two strands.

D) Because sticky ends can be temporarily held together by hydrogen bonding between the two strands.

Explanation:

Restriction enzymes cut the DNA at specific restriction sites and by the mechanism of action they can form two types of ends:

The main advantage of sticky ends (their overhangs) is that they can complementary bind to another overhand formed by the same restriction enzyme. So, for example in cloning, if the DNA of interest and plasmid vector are cut with the same restriction enzyme, that  forms sticky ends, fragment of DNA will fit into a bacterial plasmid in one direction.

On the other hand, blunt ends can be inserted into vector in both directions: head-to-tail or tail-to-head.

the relative atomic mass of an element is the mass of one atom of that element, relative to 1/12th of the mass of a  1212c atom. to convert to an absolute mass in kg, it is necessary to multiply by  1.661×10−271.661×10−27.

the relative atomic mass is roughly equal to the number of neutrons, plus the number of protons, in the nucleus of the atom.

for elements with more than one stable isotope (different types of nucleus with different numbers of neutrons but the same number of protons), the quoted mass is usually the average mass, weighted by the relative abundance of the different isotopes.