Answer:
The adult version of hemoglobin contains four subunits.
These subunits are two alpha (α) globin chains and two beta (β) globin chains.
Step-by-step explanation:
The combination of these subunits forms the hemoglobin molecule. Each globin chain is associated with a heme group, which contains an iron ion capable of binding to an oxygen molecule. This structure allows hemoglobin to transport oxygen in the blood. The most common adult hemoglobin is hemoglobin A (HbA), which consists of two alpha and two beta globin chains.