Given below are two statements: 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: (A) Both (A) and (R) are true and (R) is the correct explanation of (A). Answer: (a) Both (A) and (R) are true and (R) is the correct explanation of (A) Solution: At high altitude the atmospheric (and hence the partial pressure of oxygen, pO2) is low, so less O2 binds to haemoglobin and the body does not get sufficient oxygen, producing altitude sickness with breathing difficulty and palpitations.
- A.Both (A) and (R) are true and (R) is the correct explanation of (A)✓
- B.Both (A) and (R) are true but (R) is not the correct explanation of (A)
- C.(A) is true but (R) is false
- D.(A) is false but (R) is true
Correct Answer
(A) Both (A) and (R) are true and (R) is the correct explanation of (A)
Solution & Explanation
Answer: (a) Both (A) and (R) are true and (R) is the correct explanation of (A) Solution: At high altitude the atmospheric (and hence the partial pressure of oxygen, pO2) is low, so less O2 binds to haemoglobin and the body does not get sufficient oxygen, producing altitude sickness with breathing difficulty and palpitations. Both statements are true, and the low atmospheric pressure (reason) correctly explains the symptoms (assertion). NCERT: Ch 14, p.189, line 14 — "Binding of oxygen with haemoglobin is primarily related to partial pressure of O2"