Which of the following is an input for cellular respiration?

• A. \(\mathrm{H_2O}\)
• B. Sunlight
• C. \(\mathrm{O_2}\)
• D. \(\mathrm{CO_2}\)

Answer: (C)

Verified step by step guidance

1. Step 1: Begin by understanding the process of cellular respiration. Cellular respiration is a metabolic pathway that converts glucose and oxygen into energy (ATP), carbon dioxide (\(\mathrm{CO_2}\)), and water (\(\mathrm{H_2O}\)).
2. Step 2: Identify the inputs (reactants) required for cellular respiration. The main inputs are glucose (\(\mathrm{C_6H_{12}O_6}\)) and oxygen (\(\mathrm{O_2}\)). These are essential for the process to occur.
3. Step 3: Analyze the options provided in the question. The options are \(\mathrm{H_2O}\), sunlight, \(\mathrm{O_2}\), and \(\mathrm{CO_2}\). Compare each option to the known inputs of cellular respiration.
4. Step 4: Eliminate incorrect options. \(\mathrm{H_2O}\) is a product of cellular respiration, not an input. Sunlight is involved in photosynthesis, not cellular respiration. \(\mathrm{CO_2}\) is also a product of cellular respiration, not an input.
5. Step 5: Conclude that \(\mathrm{O_2}\) is the correct answer because it is one of the primary inputs required for cellular respiration to produce energy.