Question

The "refuge" strategy proposed by Tabashnik to slow the evolution of Bt resistance relies on:

1) the fact that Bt resistance is involved in a trade-off
2) gene flow between refuge and susceptible populations
3) a and b are correct
4) none of the above

Answer 1

as the refuge strategy to slow Bt resistance relies on both trade-offs involved in Bt resistance and gene flow between susceptible and resistant pest populations.

Step-by-step explanation:

The "refuge" strategy suggested by Tabashnik to slow down the evolution of Bt resistance in pests is indeed based on a combination of factors that involve a trade-off and gene flow.

Option 1 indicates that the refuge strategy relies on the assumption that there is a fitness cost to pests when they develop Bt resistance. This cost implies that resistant individuals may be less fit in environments without the Bt toxin, giving non-resistant pests a survival advantage in these refuges. Meanwhile, option 2 refers to the importance of allowing gene flow between susceptible pest populations (often in refuges) and the resistant populations, which can help to dilute the resistance genes and slow their spread through the pest population.

Therefore, the refugee strategy is designed to maintain a population of non-resistant pests nearby Bt crop fields. These non-resistant pests can mate with any resistant pests that may arise, reducing the chances that resistance genes will become fixed in the population.