In a positive-feedback system in which hormone A alters the amount of protein X
A)an increase in A always produces an increase in X.
B)an increase in X always produces a decrease in A.
C)a decrease in A always produces an increase in X.
D)a decrease in X always causes a decrease in A.
E)it is impossible to predict how A and X affect each other.

Question

Quizplus · Accepted Answer

In a positive-feedback system, an increase in A will always cause an increase in X, and this increase in X will cause a further increase in A. This leads to a self-reinforcing loop, resulting in a continued increase in both A and X. Therefore, choice A is the best answer.

In a Positive-Feedback System in Which Hormone a Alters the Amount