Which of the following genes control corn borer disease?

The correct answer is Option (3) → cry I Ab

The cry genes come from the bacterium Bacillus thuringiensis and code for Bt toxin proteins. Each toxin kills a particular group of insects, so the gene is chosen to match the crop and its pest.

Option (1) amp^R — Incorrect. This is the ampicillin resistance gene. It is a selectable marker in cloning vectors such as pBR322, not a pest-control gene.

Option (2) cry I Ac — Incorrect. The protein of this gene controls cotton bollworms.

Option (3) cry I Ab — Correct. The protein coded by this gene controls the corn borer.

Option (4) cry II Ab — Incorrect. Like cry I Ac, it controls cotton bollworms.

Note: A similar question was also asked in CUET (UG) 2026 on 31-05-2026 (Slot 2) and on 20-05-2026 (Slot 1), in CUET (UG) 2025 on 14-05-2025 (Slot 1), and in CUET (UG) 2023 on 25-05-2023 (Slot 3).

NCERT Extract:
Biotechnological Applications in Agriculture – “… Specific Bt toxin genes were isolated from Bacillus thuringiensis and incorporated into the several crop plants such as cotton (Figure 10.1). The choice of genes depends upon the crop and the targeted pest, as most Bt toxins are insect-group specific. The toxin is coded by a gene cryIAc named cry. There are a number of them, for example, the proteins encoded by the genes cryIAc and cryIIAb control the cotton bollworms, that of cryIAb controls corn borer.”