If the solutions and leaf disks were boiled prior to the photosynthesis I think all the leafs would sink. Photosynthesis would not ensue by the reason the proteins would be converted and not useful.
Alternatively, if the solutions and leaf disks were subjected to very cold temperatures the leaf disk will float faster.
The things that are changing in an experiment are called variables. A variable is any factor, trait, or condition that can exist in differing amounts or types. An experiment usually has three kinds of variables: independent, dependent, and controlled
