Which gas is produced as a byproduct during cellular respiration in most eukaryotic cells?

• A. Carbon dioxide (\(\mathrm{CO_2}\))
• B. Nitrogen (\(\mathrm{N_2}\))
• C. Oxygen (\(\mathrm{O_2}\))
• D. Hydrogen (\(\mathrm{H_2}\))

Answer: (A)

Verified step by step guidance

1. Understand the process of cellular respiration: Cellular respiration is a metabolic pathway that converts glucose into energy (ATP) in the presence of oxygen. It occurs in three main stages: glycolysis, the citric acid cycle (Krebs cycle), and oxidative phosphorylation.
2. Identify the byproducts of cellular respiration: During the citric acid cycle, carbon atoms from glucose are released as carbon dioxide (\(\mathrm{CO_2}\)). This is a key byproduct of the process.
3. Recall the role of oxygen (\(\mathrm{O_2}\)): Oxygen is consumed during cellular respiration as the final electron acceptor in the electron transport chain, but it is not produced as a byproduct.
4. Eliminate other options: Nitrogen (\(\mathrm{N_2}\)) and hydrogen (\(\mathrm{H_2}\)) are not involved in significant amounts during cellular respiration in eukaryotic cells, so they cannot be byproducts.
5. Conclude that carbon dioxide (\(\mathrm{CO_2}\)) is the correct answer: Carbon dioxide is released during the citric acid cycle and is expelled from the cell as a waste product of cellular respiration.