Answer:
cell, tissues, organ,organ system and organism
I think the answer is D, since the heart is not under homeostasis
The answer is urethra.
It is known that the kidneys are responsible for filtration of metabolic wastes from the blood and form urine. Urine is transported through the ureters to the urinary bladder. From the urinary bladder, urine is transported to the outside of the body by the urethra.
The answer to this question would be: insulin
Insulin is a hormone that produced by the pancreas. Insulin makes sugar go inside cells. Sugar is the food for cells. Without insulin, the sugar can't enter the cell and the cell food is depleted. This will cause the body feel that the sugar is not enough and trying to increase the sugar concentration. This will result in the increases of blood sugar level.
The best option is B He used a new experimental method to test his hypothesis.