What phenomenon occurs when a chemical blocks a detoxifying enzyme in bees, increasing pesticide toxicity?

The correct answer is synergism. This phenomenon occurs when two or more substances interact in such a way that their combined effect is greater than the sum of their individual effects. In the context of pesticide exposure, when a chemical blocks a detoxifying enzyme in bees, it hampers the bees' ability to break down and detoxify the pesticide. As a result, the toxicity of the pesticide increases, leading to more severe effects than would occur if the pesticide were present alone.

In this scenario, if the enzymatic detoxification is inhibited, the bees are unable to eliminate the pesticide from their systems effectively. This interaction illustrates synergism, as the presence of the chemical and the pesticide together results in heightened toxicity that poses a greater risk to the bee population.

Understanding this mechanism is crucial, especially for pesticide management, as it highlights the importance of considering not just the individual effects of pesticides but also how they may interact with other chemicals in the environment.