Where do restriction enzymes come from, and what is their normal physiological function?
A)Phage $\lambda$ produces them and they replicate viral DNA.
B)Phage $\lambda$ produces them and they confer antibiotic resistance.
C)They are yeast DNA replication enzymes.
D)Bacteria produce them to protect against viral invasion.
E)They are bacterial DNA replication enzymes.

Question

Quizplus · Accepted Answer

Restriction enzymes are produced by bacteria as a defense mechanism against viral invasion. They cut foreign DNA at specific sites, while leaving their own DNA unharmed. This helps to prevent viral DNA from replicating and taking over the bacterial cell.

Where Do Restriction Enzymes Come From, and What Is Their λ\lambdaλ

Where Do Restriction Enzymes Come From, and What Is Their $\lambda$