Which of the following is a reactant of cellular respiration?

Carbon dioxide
Oxygen
Energy
Water

Oxygen

Oxygen is the reactant of cellular respiration.

To determine which of the following is a reactant of cellular respiration, we need to understand the process of cellular respiration. Cellular respiration is the process through which cells convert glucose into usable energy in the form of ATP (adenosine triphosphate). It occurs in the mitochondria of cells.

The reactants of cellular respiration are glucose and oxygen, which are converted into carbon dioxide, water, and ATP. So, based on this information, the correct answer is oxygen. Oxygen is necessary for the complete breakdown of glucose into energy (ATP) during cellular respiration.

Here are the reactants and products of cellular respiration:

Reactants:
- Glucose
- Oxygen

Products:
- Carbon dioxide
- Water
- ATP

In summary, the reactants of cellular respiration are glucose and oxygen.