Question

Which of the following genes were introduced into cotton to protect it from cotton bollworms? (and = all, only = only)

• A. Cry IAc and Cry IAb
• B. Cry IAc and Bt Ab
• C. Cry II Ac and Cry I Ab
• D. Cry IAc and Cry IIAb

Hint:

Important Bt genes: \[ \boxed{ \begin{aligned} &\text{Cry IAc + Cry IIAb} &&\rightarrow \text{Bt cotton (bollworms)} &\text{Cry IAb} &&\rightarrow \text{Corn borer} &\text{Cry IIAb} &&\rightarrow \text{Cotton bollworms} \end{aligned} } \]

Answer 1

The Correct Option is D

Step 1: Recall Bt cotton. Bt cotton was developed by introducing genes from Bacillus thuringiensis. The genes introduced are \[ \boxed{\text{Cry IAc and Cry IIAb}.} \] These genes produce Bt toxins effective against cotton bollworms.

Step 2: Choose the correct option. Therefore, the correct option is \[ \boxed{(D).} \]