The toxin proteins isolated from Bacillus thuringiensis, coded by which of the following genes would contrl cotton bollworms and corn borer, respectively?

Question

Accepted Answer

A. 1. **Background**: specific Bt toxin genes were isolated from *Bacillus thuringiensis* and inserted into crop plants such as cotton and corn to make them pest-resistant.

2. Since most Bt toxins are **insect-group specific**, the choice of gene depends on which pest the crop needs protection from.

3. The gene **cryIAc** codes for a toxin protein that specifically controls **cotton bollworms**.

4. The gene **cryIAb** codes for a toxin protein that specifically controls the **corn borer**.

5. Matching this order (cotton bollworm, then corn borer) to the options, we get cryIAc and cryIAb respectively.

6. Hence, the correct answer is **A: cryIAc and cryIAb**.