Question

practice it!
you decide to investigate the question, \how does temperature affect how often crickets chirp?\
you create the hypothesis \if the temperature is warm, then the crickets will chirp more often\ based on your current observations and background knowledge.
you place crickets into three different tanks. one tank is room temperature. the second tank is heated with a lamp.
which of the following would be the best setup for the third tank of crickets?
○ an empty tank without crickets
○ a tank with extra water
○ a tank with two heat lamps
○ a tank with a layer of ice covering the lid

Explanation:

The experiment is about how temperature affects cricket chirping. To have a valid experiment, we need a control group with a different temperature (cool) to compare with room temp and warm (heated) tanks. An empty tank (no crickets) doesn't help, extra water changes a different variable, two heat lamps just increase warmth (not a new temp group), but a tank with ice (cool temp) provides a cold condition to test the hypothesis by having three temperature conditions (cool, room, warm) for comparison.

Answer:

D. a tank with a layer of ice covering the lid