The answer is amino acid.
I don't know much about bio, but for this your answer is skin. This is because it is the outer layer.
Hope this Helps!
~JaredEkey
The answer is Controlled variable
Constriction of blood vessel will reduce its diameter and increase the resistance. this will lead to higher blood pressure. The purpose of blood vessel constriction is to control the blood pressure at a certain range to make sure the blood could be distributed. Blood pressure would be the controlled variable of this mechanism.
Answer:
i need help on that question too
Explanation:
Natural selection adapted them to thrive in the habitat they live in