Final answer:
An ion channel-linked receptor, known as an ionotropic receptor, binds to a ligand and opens an ion channel through the membrane, allowing specific ions to pass through and activating a biological response.
Step-by-step explanation:
An ion channel-linked receptor, also known as an ionotropic receptor, binds to a ligand (such as a neurotransmitter) and opens an ion channel through the membrane. When the ligand binds to the receptor, ions can pass through the channel, changing the membrane's charge. This process activates a biological response by allowing specific ions to cross the membrane and affecting the cell's function.