Maize (Zea mays) crops are frequently attacked by the European corn borer (Ostrinia nubilalis), a moth larva that tunnels into maize stems and feeds on the ears. Maize plants have been genetically modified (GM) to express a gene from the soil bacterium Bacillus thuringiensis (Bt). This gene codes for the Bt delta-endotoxin, which is toxic to insect larvae but harmless to humans and other non-target organisms.
A farmer can increase the yield of maize grain by:
Explain how the use of GM Bt maize plants and the expression of the Bt toxin can increase the yield of maize grain.
Suggest two reasons why some groups of people are concerned about the widespread cultivation of GM insect-resistant crops like Bt maize. Do not refer to ethical concerns or religion in your answer.