Question

bryan grew ten mint plants on his back porch. he grew each plant in its own pot, and each pot was the same size and shape. bryan noticed that his plants did not grow many leaves, and he wanted to see if earthworms could help them grow more. to test this idea, bryan divided his ten plants into two equal groups. for one group, he added three earthworms to the soil in each pot. he did not add any earthworms to pots in the other group. two months later, bryan counted the number of leaves on each of the ten plants. he compared the number of leaves on the plants in each group. complete the sentence. in this experiment, the number of earthworms was _______________. a dependent variable an independent variable

Explanation:

In an experiment, the independent variable is what the researcher changes. Here, Bryan changes the number of earth - worms (adds earthworms to one group and not to the other). The dependent variable would be the result he measures, which is the number of leaves. So the number of earthworms is the factor that is being manipulated.

Answer:

an independent variable