Final answer:
Hgb stands for hemoglobin, a protein in red blood cells that carries oxygen. Hemoglobin A1c is a glycosylated form of hemoglobin used to monitor diabetes management, and other hemoglobin variants adapt to environmental or health conditions.
Correct option is A
Step-by-step explanation:
The abbreviation Hgb stands for hemoglobin. Hemoglobin is a vital protein molecule found in red blood cells (erythrocytes) and it consists of four subunits: two alpha subunits and two beta subunits, which surround a central heme group containing iron. This structure allows hemoglobin to bind to oxygen molecules, facilitating the transportation of oxygen around the body from the lungs to various tissues, as well as helping in the transport of some carbon dioxide back to the lungs for exhalation.
There are several minor components of hemoglobin A, such as hemoglobin A1c (HbA1c), which is a glycosylated variant that is used to monitor the long-term control of diabetes mellitus. Hemoglobin derivatives and variants provide adaptations to different environmental or health conditions, such as Hgb-S leading to sickle-cell anemia that offers protection against malaria, or Hgb-F (fetal hemoglobin), which efficiently transports oxygen in low oxygen conditions.