A phyloGENETIC tree is not the same thing as a taxonomic tree, which is what Cal described. rRNA and molecular studies are used in phylogenetics to determine relations between species.
1 As the light intensity increases, the rate of photosynthesis increases. 2  However, the rate will not increase beyond a certain level of light intensity. 3  At high light intensities the rate becomes constant, even with further increases in light intensity, there are no increases in the rate.
Then, with the increase of light intensity will cause in the decrease in the time taken for the leaf discs to float on the surface of the solution which represents the increase of the rate of photosynthesis. Hence, hypothesis is accepted.