Question

Which of the following is an incorrect statement about restriction enzymes?

a. They are used in genetic engineering.
b. They cut DNA at specific recognition sequences.
c. They are always derived from bacteria.
d. They do not cleave RNA.

Answer 1

The incorrect statement about restriction enzymes is that they are always derived from bacteria, as they can be derived from other organisms as well. They are used to cleave DNA at specific sites, usually palindromic sequences, but do not normally cleave RNA.

Step-by-step explanation:

The statement that is incorrect about restriction enzymes is: c. They are always derived from bacteria. While the majority of restriction enzymes are derived from bacteria, they can also come from other organisms such as archaea. These enzymes recognize specific, often palindromic, DNA sequences and cleave the DNA at these sites, which is crucial for genetic engineering, molecular cloning, and recombinant DNA technology. They are known for their high specificity, typically only cleaving DNA that contains the exact sequence they recognize, leaving the organism's own DNA unharmed due to protective methylation. Unlike restriction enzymes, which do not normally cleave RNA, other enzymes such as ribonucleases are responsible for breaking down RNA molecules.