Question

control group
question id : 2036119
a scientist is testing the effect of a new plant food on the growth of sunflowers. the scientist uses two groups of sunflower seeds: one group receives the new plant food, and the other group receives water only. what is the purpose of the group that receives only water?
a to measure how much water sunflowers need
b to see how tall sunflowers can grow without water
c to compare with the group that receives the new plant food
d to observe the effect of sunlight on sunflowers

Explanation:

The scientist is testing the effect of new plant food on sunflower growth. The group with only water is a control group, used to compare with the group that gets the plant food. Option A is about measuring water need (not relevant). Option B is about growth without water (not the case here, as the control group gets water). Option D is about sunlight (not the variable tested). So the purpose of the water - only group is to compare with the plant - food group.

Answer:

C. To compare with the group that receives the new plant food