Question

At high altitude, the,

(A) number of RBC increases
(C) number of RBC decreases
(B) size of RBC increases
(D) size of RBC decreases​

Answer 1

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$\bigstar$ (A) number of RBC increases $\bigstar$

Explanation:

At high altitudes, there is a decrease in oxygen hemoglobin saturation. This hypoxic condition causes hypoxia-inducible factor 1 to become stable and stimulates the production of erythropoietin (EPO), a hormone secreted by the kidneys. EPO stimulates red blood cell production from bone marrow in order to increase hemoglobin saturation and oxygen delivery.

Thus, the total number of RBC increases.

Answer 2

Explanation:

(A) number of RBC increases