Ontario Grade 9 Science Class Practice Exam 2025 - Free Grade 9 Science Practice Questions and Study Guide.

The correct equation for cellular respiration is C6H12O6 + 6O2 ---> 6CO2 + 6H2O. This is because the process of cellular respiration involves breaking down glucose (C6H12O6) into carbon dioxide (CO2) and water (H2O) in the presence of oxygen (O2) to release energy in the form of ATP. Option B is the opposite of the correct equation and does not accurately represent the process of cellular respiration. Option C and D do not include all of the necessary components, such as glucose, oxygen, and carbon dioxide. Therefore, option A is the most accurate and complete equation for cellular respiration.