Explain three similarities and two diffrences in anaerobic and aerobic cellular respiration. Solution Difference: 1. Anaerobic respiration occurs without the presence of oxygen while aerobic respiration requires oxygen. 2. Substrates are not completely combusted in anaerobic respiration while in aerobic respiration, substrates are completely combusted. Similarities: 1. Both begin with the breakdown of sugar - glucose 2. Both produce ATP 3. Both takes place in eukaryotic cells 4. Process starts in cytosol.