Question

7. Assertion (A): Lungs always contain a residual volume of air.

Reason (R): It provides sufficient time for oxygen to be absorbed and for carbon di oxide to

be released.

a) Both A and R are true and R is the correct explanation of A.

b) Both A and R are true and R is not the correct explanation of A.

c) A is true but R is false.

d) A is false but R is true.

e) Both A and R are false.​

Answer 1

Option (a) Both A and R are true and R is the correct explanation of A.

Explanation:

Lungs always contain residual volume of air so that there will be sufficient time for inhalation (oxygen to be absorbed) after exhalation (carbon dioxide to be released.)

Answer 2

Answer:

Assertion and reason are correct and reason is the correct option of assertion.

Explanation:

Residual volume: The amount of air left inside the lungs after a normal exhalation is known as residual volume. It is important for luns to retain some amount of air after exhalation. In the absence of air, there are changes that lung tissues may stick with each other, consequently, lungs can not be reinflated. In this way, there are chances of collapse of lungs.

 The residual volume provide enough time for lungs t carry out gaseous exchange.

So both assertion and reason are correct.