Which of the following is an example of a positive feedback?
A.
A low level of oxygen in the blood triggers production of red blood cells, which transport oxygen.
B.
An increase in blood sugar level stimulates the pancreas to secrete insulin, which lowers blood sugar level.
C.
A tear in the lining of a blood vessel triggers the accumulation of blood platelets, which cause blood to clot.
Reset Next
1 answer
The correct answer is:
C. A tear in the lining of a blood vessel triggers the accumulation of blood platelets, which cause blood to clot.
This is an example of positive feedback because the initial stimulus (the tear in the blood vessel) leads to a process (accumulation of platelets) that amplifies the response (blood clotting) until the situation is resolved.
