Which two of the following changes (i-iv) usually tend to occur in the plain dwellers when they move to high altitudes (3,500 m or more)? (i) Increase in red blood cell size (ii) Increase in red blood cell production (iii) Increased breathing rate (iv) Increase in thrombocyte count Changes occurring are?
Correct answer: A. (ii) and (iii)
- A. (ii) and (iii)
- B. (iii) and (iv)
- C. (i) and (iv)
- D. (i) and (ii)
Explanation
(ii) Increase in red blood cell production: When individuals move to high altitudes, there is a decrease in the availability of oxygen. As a response, the body increases the production of red blood cells to enhance oxygen-carrying capacity and improve oxygen delivery to tissues. (iii) Increased breathing rate: At higher altitudes, the partial pressure of oxygen in the air is lower, leading to reduced oxygen uptake in the lungs. To compensate for this, the body increases the breathing rate, allowing more oxygen to be taken in and delivered to the tissues.
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