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.

Question

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.

anonymous · Answer

It is controlled because the host of the experiment is allowed to choose what he wants to input and leave out of his experiment. The manipulated variable is that of the fertilizer...how one control group has fertilizer and the other group is without fertilizer. It is a variable in his experiment, and really that is the only one. Hope this helps. 
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