I believe the answer would be <span> aerobic reactions require oxygen and anaerobic do not. From the word, aerobic itself, it would mean that the process requires the presence of oxygen for it to happen while the opposite is called an anaerobic process.</span>
Since it’s natural environment is very acidic, putting pepsin in a very alkaline environment would cause it to denature.
The variety of living organisms living on the earth is referred as biodiversity or biomes