In Bt cotton plant, the insecticidal protein encoded by the genes cry1Ac and cry IIAb control -
Answer & explanation
Correct answer: option 1
The correct answer is Option (1) → Cotton bollworms
Option (1) Cotton bollworms — Correct. Bollworms are the caterpillars of moths. They bore into the cotton bolls and destroy the crop. Bt cotton carries cry genes chosen against this very pest, so the plant makes its own insecticidal protein.
Option (2) Corn borer — Incorrect. The corn borer is a pest of maize. It is controlled by the protein of a different gene, cryIAb, not by the pair named in the question.
Option (3) Meloidogyne incognita — Incorrect. Meloidogyne incognita is a nematode (roundworm), not an insect. It infects the roots of tobacco. It is controlled by RNA interference, which silences one of its own mRNAs, not by a Bt toxin.
Option (4) Wheat borer — Incorrect. Wheat is not one of the Bt crops that NCERT describes. The genes in the question were picked for the pest of cotton, not for a pest of wheat.
NCERT Extract:
Biotechnological Applications in Agriculture – …
Figure 10.1 Cotton boll: (a) destroyed by bollworms; (b) a fully mature cotton boll