Question

Which of the following statement(s) is/are true regarding air breathing, surface dwellers?

(i) Underwater pressure let their lungs collapse.
(ii) Collapsed lung can make them float on water.
(iii) Oxygen is stored in the muscle tissues.

• A. (i) and (iii) are true
• B. (ii) and (iii) true
• C. (i), (ii), and (iii) are true
• D. only (ii) is true

Answer 1

The correct option is A (i) and (iii) are true

$\bullet$ All aquatic organisms have adaptations to fight with pressure of underwater current other than surface dwellers, E.g., whales, seals, etc.
$\bullet$ Instead of fighting the pressure, they let it collapse their lungs completely, storing oxygen in their muscles. Their muscle tissue contains much higher concentrations of oxygen-binding chemical.
$\bullet$ Collapsed lungs become heavier than water, and so it sinks, saving its oxygen stores, for the strenuous climb back to the surface.