In the first stage of cellular respiration (glycolysis), two molecules of pyruvate are produced. In the remaining stages of cellular respiration, a number of additional products are produced, such as . These other stages occur in the .

Explanation:

In the process of glycolysis, glucose molecule is enzymatically broke down into two pyruvate molecules, which occurs almost in all cells ( eukaryotes as well as prokaryotes). In case of eukaryotes, glycolysis occur in cytoplasm. In the process of glycolysis; Pyruvate, NADH and ATP are produced. After generation of pyruvate , pyrvate is converted into acetyl CoA,  which in the mitochondria is further used in energy production.

the denominator has a very specific role.

the fossil record provides evidence of a common ancestor to many species.