Platelets,which have negatively charged cell membranes,adhere to the positively charged surface of a torn blood vessel.As they do so,they release substances that attract more platelets to the damaged area and change the charge on their cell membranes to positive.More platelets adhere to the damaged area.The cycle repeats until the damaged area is sealed.What sort of feedback loop is formed?
A) This is a positive feedback loop because the response reinforces the initial change.
B) This is a negative feedback loop because the response opposes the initial stimulus.
C) This is a negative feedback loop because having too many platelets in one area blocks blood flow.
D) This is a positive feedback loop because the response prevents a person from hemorrhaging to death.

Question

Quizplus · Accepted Answer

The described feedback loop is a positive feedback loop because the response reinforces the initial change, in this case, the adherence of platelets to the damaged area. This leads to the release of substances that attract more platelets to the area, which in turn reinforces the initial response, eventually leading to the sealing of the damaged area.

Platelets,which Have Negatively Charged Cell Membranes,adhere to the Positively Charged