Final answer:
A rightward shift in the hemoglobin dissociation curve is caused by conditions that lower hemoglobin's affinity for oxygen, such as increased carbon dioxide, increased 2,3-DPG, higher body temperature, and certain blood disorders.
Step-by-step explanation:
A rightward shift of the hemoglobin (Hb) dissociation curve indicates a decreased affinity of hemoglobin for oxygen, which facilitates oxygen delivery to the tissues. This shift can be caused by several physiological changes:
- Increased carbon dioxide levels in the blood, which react with water to form bicarbonate (HCO3) and hydrogen ions (H+), leading to a lower pH.
- Increased body temperature, such as during fever or exercise, which reduces the affinity of hemoglobin for oxygen.
- Conditions like sickle cell anemia and thalassemia, which affect hemoglobin structure and function.
Therefore, the correct answer to the question about what causes a right shift of Hb is D) Increased 2,3-DPG.