Scientists tested the effect of a fertilizer on the growth of plants. they had 2 sets of plants, group a which gets fertilizer, water and sun and group b which gets only water and sun (but in equal amounts to group a).
1. explain how this scenario is a controlled experiment and identify the manipulated variable.

2. if the scientists only performed 1 experiment but it supported their hypothesis, why can it not be considered a theory?

3. the graph below was created showing the growth of the plant. how would you know that the y-axis is measuring the growth of the plant?