Question

In vitro, group I introns have the ability to

• A. undergo autosplicing in the presence of an external nucleophile
• B. undergo autosplicing without the need of a nucleophile
• C. make secondary structures that are similar to that of group II introns
• D. undergo complete self-degradation

Hint:

Group I introns are fascinating because they can self-splice, a process that does not require proteins or nucleophiles.

Answer 1

The Correct Option is A

Step 1: Understanding group I introns.
Group I introns are a class of self-splicing ribozymes that can catalyze their own excision from precursor RNA without requiring any external proteins or nucleophiles. This is a characteristic feature of these introns.

Step 2: Analyzing the options.
(A)undergo autosplicing in the presence of an external nucleophile: Incorrect, as group I introns do not require an external nucleophile for their splicing.
(B)undergo autosplicing without the need of a nucleophile: Correct — Group I introns can self-splice without requiring any external nucleophile.
(C)make secondary structures that are similar to that of group II introns: This is incorrect; while both groups are ribozymes, their secondary structures differ.
(D)undergo complete self-degradation: This is incorrect; group I introns do not degrade themselves but rather catalyze their own excision.

Step 3: Conclusion.
The correct answer is (B)undergo autosplicing without the need of a nucleophile, as this is a defining feature of group I introns.