Why does breathing become difficult as we move upward in the atmosphere?
Answer and explanation
Correct answer: Air pressure and the availability of oxygen decrease
As altitude increases, the weight of the air column above a person decreases, so atmospheric pressure and air density fall. The percentage of oxygen in dry air remains close to 21 percent, but the lower pressure means fewer oxygen molecules enter the lungs in each breath. This reduces oxygen intake and can cause breathlessness or altitude sickness. Thus option C is correct; the other statements are false.
Frequently asked questions
What is the correct answer to this question?
Air pressure and the availability of oxygen decrease
Why is this the correct answer?
As altitude increases, the weight of the air column above a person decreases, so atmospheric pressure and air density fall. The percentage of oxygen in dry air remains close to 21 percent, but the lower pressure means fewer oxygen molecules enter the lungs in each breath. This reduces oxygen intake and can cause breathlessness or altitude sickness. Thus option C is correct; the other statements are false.
Which subject and chapter does this question cover?
This is a Class 11 Accountancy question. Chapter: Theory Base of Accounting.
Student feedback
Was this question useful?
👍 0 Helpful 👎 0 Not helpful
Yes 0% No 0%
0 responsesStudent Reviews
No published reviews yet.
