NEETZoologyBiotechnology and Its Applications
Given below are two statements: one is labelled as Assertion (A) and the other is labelled as Reason (R). Assertion (A): Transgenic crops expressing the Bt toxin gene are not effective in controlling infestations by the nematode Meloidogyne incognita. Reason (R): The cry genes isolated from Bacillus thuringiensis encode toxic proteins that are specific to certain insect orders like Lepidopterans and Coleopterans. In
Options
- ABoth Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of Assertion (A)
- BBoth Assertion (A) and Reason (R) are true but Reason (R) is not the correct explanation of Assertion (A)
- CAssertion (A) is true but Reason (R) is false
- DAssertion (A) is false but Reason (R) is true
Correct answer
A. Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of Assertion (A)
Step-by-step solution
Meloidogyne incognita is a nematode that infects the roots of tobacco plants. It is controlled using the strategy of RNA interference (RNAi), not by Bt toxin. The Bt toxin, produced by Bacillus thuringiensis and encoded by cry genes, is an insecticidal protein. It specifically targets insect pests belonging to orders such as Lepidopterans, Coleopterans, and Dipterans, and has no effect on nematodes. Therefore, both Assertion (A) and Reason (R) are true, and Reason (R) correctly explains why Bt crops are not effecti