Substance A is synthesized in the liver, travels through the circulatory system bound to a carrier protein, and causes a change in gene expression in a target cell. This is an example of ____.
A) autocrine signaling
B) paracrine signaling
C) long-distance signaling
D) local signaling
E) communication by direct contact

Question

Quizplus · Accepted Answer

This scenario describes long-distance signaling, as substance A is produced in one part of the body (the liver), travels through the circulatory system, and affects cells in a different part of the body by changing gene expression. This is characteristic of hormones, which are a classic example of long-distance signaling.

Substance a Is Synthesized in the Liver, Travels Through the Circulatory