Question

A signal molecule is also known as a(n) _____.

(a) receptor
(b) ligand
(c) protein
(d) initiator

Answer 1

A signal molecule is also known as a ligand. Ligands are small, usually water-soluble molecules that bind to receptors on target cells. When a ligand binds to a receptor, it initiates a signaling pathway, which can lead to various cellular responses.

Step-by-step explanation:

A signal molecule is also known as a ligand. Ligands are small, usually water-soluble molecules that bind to receptors on target cells. When a ligand binds to a receptor, it initiates a signaling pathway, which can lead to various cellular responses.