The biological role of restriction enzymes is to:
A) aid recombinant DNA research.
B) degrade foreign DNA that enters a bacterium.
C) make bacteria resistant to antibiotics.
D) restrict the damage to DNA by ultraviolet light.
E) restrict the size of DNA in certain bacteria.

Question

Quizplus · Accepted Answer

The biological role of restriction enzymes is to identify and cleave (cut) foreign DNA that enters a bacterium, such as that of a virus, bacteriophage, or plasmid. This helps to protect the bacterium from potential harm by degrading the foreign genetic material. In recombinant DNA research, restriction enzymes are used to cut DNA at specific sites in order to create fragments that can be joined with other DNA molecules. However, this is a secondary application of restriction enzymes that is not related to their biological role in bacteria.

The Biological Role of Restriction Enzymes Is To