Independent variable - pH level Dependent variable - Time taken for starch to be broken down. Control variables - Temperature, volume and concentrations of enzyme solution and starch solution.

This process, called photosynthesis, is essential to the global carbon cycle and organisms that conduct photosynthesis represent the lowest level in most food chains (Figure 1). Most living things ...

In terms of importance, cellular biologist Geoffrey McFadden wrote in a study published in Plant Physiology that "the origin of oxygenic photosynthesis must rank just after the origin of life itself." ...