Final answer:
The log-dose response curve for a partial agonist resembles that of a full agonist with an antagonist; it plateaus below the maximum effect even at high doses due to its lower intrinsic activity.
Step-by-step explanation:
The log-dose response curve for a partial agonist is similar to the curve for a full agonist but does not reach the same maximum effect, even with high doses. A full agonist has the ability to produce a maximal response by fully activating the receptor it binds to. In contrast, a partial agonist can only produce a sub-maximal response, even when it has fully occupied the available receptors. This is because partial agonists have lower intrinsic activity compared to full agonists. Therefore, the correct answer to what the curve for a partial agonist looks like is most similar to 'B. like the curve for a full agonist with an antagonist', as the presence of a competitive antagonist would also limit the maximal effect a full agonist could achieve. To clarify this with the provided information, a drug is called an agonist if it activates a receptor and produces a biological response. An antagonist blocks the receptor and prevents an agonist from producing its effect.