In this model food web the only feeding links are these: grasshoppers eat grass; frogs eat grasshoppers; snakes eat frogs. Grass is the only food of the grasshoppers in this web. If all the grass is removed and nothing else in this web changes, what happens to the grasshopper population?

Explanation

The stated web gives the grasshoppers no food other than grass, so removing the grass removes their entire energy supply and the population falls. The choice about having fewer plants to contend over fails, because the web never states another species contending with the grasshoppers for grass; the only thing that changed is that their sole food is gone.