A nematode, Meloidogyne incognita infects the roots of _____ and causes a great reduction in yield.
Answer & explanation
Correct answer: option 3
The correct answer is Option (3) → Tobacco
Meloidogyne incognita is a nematode (roundworm) that lives as a parasite in plant roots. NCERT uses it as its example of how RNA interference (RNAi) can make a plant pest-resistant: genes of the nematode are put into the host plant, and the double-stranded RNA formed silences a needed mRNA of the parasite, so it cannot survive in that plant.
Option (1) Potato — Incorrect. Potato is a crop grown from its tubers, which are swollen underground stems. It is not the plant in NCERT’s example of this nematode.
Option (2) Tomato — Incorrect. Tomato appears in the book as a food plant raised on a large scale by micro-propagation, not as the host of this nematode.
Option (3) Tobacco — Correct. Tobacco is the host plant of this nematode in NCERT’s example. The RNAi method was used to make tobacco plants resistant to it.
Option (4) Cotton — Incorrect. Cotton is protected by Bt toxin genes against bollworms, which are insects, not nematodes.
NCERT Extract:
Biotechnological Applications in Agriculture – …
