What is TRUE of restriction enzymes?
A)they randomly cleave DNA at sites within a genome
B)they catalyze the formation of hydrogen bonds between DNA fragments
C)they protect bacterial cells from invasion by foreign DNA
D)they are not naturally produced by bacteria,but are bioengineered by humans
E)there are less than 10 restriction enzymes known

Question

Quizplus · Accepted Answer

Restriction enzymes are naturally produced by bacteria as a defense mechanism against foreign DNA, protecting their genome from invasion by foreign genetic material.

Answer: A
 Restriction enzymes have specific recognition sequences and only cleave DNA at those particular sites within a genome. The cleavage can be random within those specific recognition sequences.

Answer: E
 There are over 3,000 known types of restriction enzymes, making this statement false. Restriction enzymes are classified by their recognition sequence, and some of them are commonly used in laboratory techniques such as DNA cloning and gene editing.

Therefore, the correct answer is C and A only.

What Is TRUE of Restriction Enzymes