A control group of the experiment is the one in which no treatment or intervention is given. So, in your case, the pea plants in which was not subjected any of the fertilizers, will serve as a control group. This is a negative control. A positive control group is the one in which an established treatment is given, which definitely leads to the production of the desired character. So, in your case, a very good well-known fertilizer which has a positive control on the growth of the pea plant, would serve as a positive control.
Answer: Kidney
Explanation:
Kidney is a structure that is located toward the dorsal side of the body, lateral and superior to the hamstring but inferior to the heart.
The kidneys are a pair of bean shaped organs that are located at the downward part of the rib cage. The body of humans consists of two kidneys one kidney on each side of the spine and they're responsible for the filtering of excess water, waste products, and other impurities out of the human body.
