The end products of a biological process are ethanol and carbon dioxide with the release of energy. Name this process and write the pathway involved in the reaction.

Which of the following is known as the energy currency of the cell in biology?

The breakdown of pyruvate to give carbon dioxide,water and energy takes place in

An organism $X$ having breathing organs $A$ lives on land. When organism $X$ goes underwater, it cannot survive for a long time unless carrying an oxygen cylinder. On the other hand, the organism $Y$ having breathing organs $B$ always lives in water and if taken out of water, it dies after a short while. A third organism $Z$ having breathing organs $C$ and $D$ which lives on the banks of ponds, lakes, and rivers can survive on land as well as in water equally well.
$(a)$ What could organism $X$ be? Name the breathing organs $A$.
$(b)$ What could organism $Y$ be? Name the breathing organs $B$.
$(c)$ What could organism $Z$ be? Name the breathing organs $C$ and $D$.
$(d)$ Out of $X$, $Y$, and $Z$, which organism is:
$(i)$ Amphibian,
(ii) Aquatic,
(iii) Terrestrial?

What are respiratory substrates? Give one example.

Distinguish between aquatic and terrestrial respiration.