Vestigial structures don't hurt the living being. Nature chooses against just unsafe attributes. Structures that have no obvious capacity and have all the earmarks of being lingering parts from a past progenitor are called minimal structures. Cases of minimal structures incorporate the human informative supplement, the pelvic bone of a snake, and the wings of flightless flying creatures.
Answer: Cellular respiration
Explanation:
In the presence of oxygen glucose is oxidised through a series of enzyme coordinated reactions to produce energy which is stored in form of ATP.