Explain how it would benefit deep-sea divers if humans also had gills.

What advantage over an aquatic organism does a terrestrial organism have with regard to obtaining oxygen for respiration?

In cockroaches, air enters the body through:

There are five animals $P$, $Q$, $R$, $S$ and $T$. The animal $P$ always lives in water and has gills for breathing. The animal $Q$ can stay in water as well as on land and can breathe through both, moist skin and lungs. The animal $R$ lives in soil and breathes only through its skin. The animal $S$ lives on land and breathes through spiracles and tracheae. The animal $T$ lives in water and breathes through its cell membrane. Identify the animals:
$(a)$ Which of the animals could be $Amoeba$?
$(b)$ Which of the animals could be frog?
$(c)$ Which animal could be fish?
$(d)$ Which animal could be grasshopper?
$(e)$ Which animal could be earthworm?

Differentiate between the left lung and the right lung of humans.

In the following questions, a statement of Assertion $(A)$ is followed by a corresponding statement of Reason $(R)$. Mark the correct answer as:
Assertion $(A)$: Exchange of oxygen and carbon dioxide occurs between blood vessels and alveoli.
Reason $(R)$: Oxygen diffuses from alveoli to blood vessels and carbon dioxide diffuses from blood vessels to alveoli.