What is the main feature of Type II restriction enzymes?

Correct answer: They usually cut DNA within or near the recognition site

The direct answer is B: Type II enzymes usually cut DNA within or near their recognition site. A restriction enzyme recognizes a particular short DNA sequence, often a palindrome, and Type II enzymes cut at a defined position relative to that sequence. Because the position is predictable, scientists can prepare vector and insert ends for cloning. Option A is wrong because these enzymes cut DNA, not only proteins. Option B is correct because predictable DNA cutting is their defining useful feature. Option C is wrong because joining DNA is the job of DNA ligase, not a restriction enzyme. Option D is wrong because restriction enzymes do not color RNA; staining is a separate laboratory procedure. Exam cue: Type II means a specific site and a reproducible cut.