Q. Which two of the following changes (a–d) usually tend to occur in the plain dwellers when they move to high altitudes (3,500 m or more)? (a) Increase in red blood cell size (b) Increase in red blood cell production (c) Increased breathing rate (d) Increase in thrombocyte count Changes occurring are
A) (a) and (b)
B) (b) and (c)
C) (c) and (d)
D) (a) and (d)
Explanation
[Solution from source] At high altitude the low partial pressure of O₂ makes the body compensate by producing more RBCs (through erythropoietin) and by breathing faster. RBC size and platelet count do not rise as part of this acclimatisation. Answer (2).
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.