Why is respiration in insect called direct respiration?

Respiration is

What is respiration?

Define respiration

Respiration in insects is called direct because.

Why is less energy produced during anaerobic respiration than in aerobic respiration?

Why is respiration a catabolic process?

The energy yield in terms of ATP is higher in aerobic respiration than during anaerobic respiration. Why is there anaerobic respiration even in organisms that live in aerobic condition like human beings and angiosperms?

Less energy is produced during anaerobic respiration that in aerobic respiration. Justify.

What is anaerobic respiration?

Describe cellular respiration.