Question

According to the Janzen-Connell hypothesis, in order for pathogens or herbivores to contribute to the maintenance of diversity? Select all that apply. The pathogens/herbivores must result in lower seedling mortality close to adult plants of the same species. The infections must be avirulent. Mortality of seedlings due to competition between plants must be less important than mortality due to herbivores/pathogens. The pathogens/herbivores must be host-specific. . Fractions of a field of Bt crops planted with non-Bt-expressing varieties: Select all that apply. lead to higher losses to pests in the short term than if no fractions were planted with non-Bt-expressing varieties, but maintain the effectiveness of Bt in protecting crops in the long term. o ensure that selection for Bt resistance is not too intense within herbivore populations. impede the complete eradication of important agricultural pests. ensure that herbivore genes conferring susceptibility to Bt are well represented in the next generation.

Answer 1

Accoriding to Janzen–Connell hypothesis herbivores and pathogens maintain diversity in plant by lowering the survival rate of seeds and seedlings which are close to the reproductive adults. Hence the correct option here is third option.