Assertion (A): A person goes to high altitude and experiences 'altitude sickness' with symptoms like breathing difficulty and heart palpitations. Reason (R): Due to low atmospheric pressure at high altitude, the body does not get sufficient oxygen. In the light of the above statements, choose the correct answer from the options given below:
Answer: (C) Both (A) and (R) are true and (R) is the correct explanation of (A). Answer: (c) Both (A) and (R) are true and (R) is the correct explanation of (A) Solution: At high altitude the atmospheric pressure (and hence the partial pressure of O2) is low, so haemoglobin cannot be saturated adequately and the body gets insufficient oxygen.
- A.(A) is true but (R) is false
- B.(A) is false but (R) is true
- C.Both (A) and (R) are true and (R) is the correct explanation of (A)✓
- D.Both (A) and (R) are true but (R) is not the correct explanation of (A)
Correct Answer
(C) Both (A) and (R) are true and (R) is the correct explanation of (A)
Solution & Explanation
Answer: (c) Both (A) and (R) are true and (R) is the correct explanation of (A) Solution: At high altitude the atmospheric pressure (and hence the partial pressure of O2) is low, so haemoglobin cannot be saturated adequately and the body gets insufficient oxygen. This hypoxia produces altitude sickness — breathing difficulty and heart palpitations. The low atmospheric pressure is thus the direct cause, so R correctly explains A. NCERT: Ch 14, p.189, line 14 — "Binding of oxygen with haemoglobin is primarily related to partial pressure of O2"