Final answer:
Red cells' affinity for oxygen is influenced by factors like pH, CO2 partial pressure, and BPG, which alter the oxygen dissociation curve. Hemoglobin's affinity increases with oxygen binding due to positive cooperativity. The hormone EPO stimulates red cell production in response to low oxygen levels.
Step-by-step explanation:
The correct relationship between red cells' affinity for oxygen and red cell production is multifactorial and affected by various conditions and substances. Red cells' affinity for oxygen is influenced by factors such as pH levels, carbon dioxide partial pressure, temperature, and the presence of 2,3-bisphosphoglycerate (BPG). For example, an increase in carbon dioxide or a decrease in pH level causes the oxygen dissociation curve to shift right, reducing hemoglobin's affinity for oxygen and requiring more oxygen to achieve the same saturation level. Conversely, as hemoglobin binds oxygen molecules, its affinity for additional oxygen increases (positive cooperativity). In terms of red cell production, the kidney-produced hormone erythropoietin (EPO) stimulates the production of red blood cells in the bone marrow. This occurs in response to lowered oxygen levels, such as moving to high altitude or starting an aerobic exercise program. Conditions like anemia, due to various causes, can trigger increased EPO production to enhance red cell production and improve oxygen delivery.