Cellular respiration is the process through which organic compounds are broken down enzymatically to release energy in form of ATP in the cell. Cellular respiration occurs in the mitochondria and cytoplasm.
Mitochondria contain enzymes that catalyze and control reactions of respiration. The inner membrane is folded into cristae to create large surface area for attachment of enzymes. The end products of cellular respiration are carbon dioxide, water and energy.
The most likely cause of the beak variation is the food source of the finch, the break size and shape was adapted to most likely have easier and better access to food. <span />