How does the structure of fetal hemoglobin (HbF) differ from adult hemoglobin (HbA), and what is the significance of this difference in terms of oxygen binding affinity?

A Fetal hemoglobin has a lower affinity for oxygen due to a higher concentration of 2,3-Bisphosphoglycerate
B Fetal hemoglobin has a higher affinity for oxygen because it lacks 2,3-Bisphosphoglycerate, allowing for better oxygen transfer from mother to fetus ✓
C The structure of fetal hemoglobin includes an additional alpha-globin subunit, increasing its molecular weight and enhancing oxygen binding
D Fetal hemoglobin is composed entirely of delta-globin chains, which have a lower affinity for oxygen than alpha-globin chains found in adult hemoglobin

Explanation

Fetal hemoglobin (HbF) has a higher affinity for oxygen than adult hemoglobin (HbA) because it is less affected by 2,3-Bisphosphoglycerate (2,3-BPG), a molecule that decreases hemoglobin's affinity for oxygen. This higher affinity allows for more efficient transfer of oxygen from the mother's bloodstream to the fetus.

Source

Wintrobe's Clinical Hematology
Hematology Hematology: Hemoglobin and Oxygen Transport Hematology: Hemoglobin and Oxygen Transport Hard MEDICAL Confidence: high