Solution:Concept: Aerobic means in presence of air and anaerobic means absence of air. Cellular respiration is a metabolic process in which chemical energy gets converted into ATP. It is a catabolic reaction involving the breakdown of larger molecules into smaller ones.
There are two types of respiration:
Aerobic and anaerobic respiration. Aerobic respiration involves oxygen and produces energy from food. The end products are water and carbon dioxide. Anaerobic respiration is the breakdown of glucose to obtain ATP but in absence of oxygen. In this, electron acceptors are used instead of molecular oxygen to produce the energy.
Hence, the correct answer is option 1.