Final answer:
The terms biconcave and anucleated apply to red blood cells. These cells are specialized for oxygen transport, lack a nucleus, and have a distinct biconcave shape that maximizes surface area for gas exchange.
Step-by-step explanation:
The terms biconcave and anucleated specifically apply to red blood cells. Red blood cells, or erythrocytes, are specialized cells that circulate in the body, delivering oxygen to other cells. In mammals, including humans, these erythrocytes are distinctive for their biconcave shape — which maximizes their surface area for gas exchange — and they are anucleated, meaning they do not contain a nucleus at maturity. This structure allows more room for the oxygen-carrying protein hemoglobin. White blood cells, in contrast, are part of the immune system and do contain a nucleus. Platelets, which are fragments essential for blood clotting, are not cells but cell fragments and also do not meet the description of being both biconcave and anucleated. Therefore, the correct answer to the question is option 2) Red blood cells.