Question

The genes present in Bollgard II Cotton are

• A. Cry1Ac and Cry 2Ab
• B. Cry1Ac and CP4-EPSPS
• C. Cry1Ac and Cry1Fa1
• D. Barnase/Barstar genes

Hint:

Bollgard I has one gene (Cry1Ac), while Bollgard II pyramided a second gene (Cry2Ab) to delay pest resistance through dual-mode insecticidal action.

Answer 1

The Correct Option is A

Step 1: Understanding the Concept:
Bollgard is a brand of genetically modified, insect-resistant cotton developed to express crystal proteins from the soil bacterium Bacillus thuringiensis (Bt).
These proteins provide targeted protection against destructive lepidopteran insect pests, such as the bollworm.

Step 2: Detailed Explanation:
The first-generation Bollgard cotton (Bollgard I) expressed a single insecticidal Bt protein, Cry1Ac.
To delay the development of insect resistance to this single toxin, second-generation Bollgard II cotton was developed using a gene pyramiding strategy.
Bollgard II contains two distinct Bt genes: Cry1Ac and Cry2Ab.
These genes express two different crystal proteins that target different binding sites in the midgut of susceptible lepidopteran larvae.
CP4-EPSPS (B) is a gene that confers tolerance to glyphosate herbicide, which is found in Roundup Ready crops rather than standard Bollgard II cotton.
Barnase and Barstar (D) are genes used to create genetic male sterility systems for hybrid seed production.
Therefore, Bollgard II cotton contains both the Cry1Ac and Cry2Ab genes.

Step 3: Final Answer:
The correct option is (A).