In transduction pathways used by cells, a physical or chemical stimulus from the environment acts as a
A) peptide.
B) signal.
C) hormone.
D) response.
E) key.

Question

Quizplus · Accepted Answer

In transduction pathways, the physical or chemical stimulus from the environment acts as a signal which triggers a series of biochemical reactions inside the cell leading to a response. Peptides and hormones can also be part of these pathways, but they are not the main signal that initiates the transduction process. A key may be used as an analogy to explain how a signal molecule fits into a receptor site on a cell membrane, but it is not the actual term used to describe the stimulus in transduction pathways.

In Transduction Pathways Used by Cells, a Physical or Chemical