Science Fair Project: Comparing Sun Leaf And Shade Tree

My science fair project is about comparing sun leaf and shade leaf. The purpose of my project is to find out the answer of these questions: Do leaf size and shape according to their position on the tree? What are the differences between sun and shade leaves? How does photosynthesis work on plants? In this experiment I compared leaves of the same plant that grows in high light and low light environments, and observe that the low light plant has adapted to increase its efficiency of light capture for photosynthesis.

I need 24 leaves from three different species of trees, some plastic bags and graph paper. First, I searched some information online to identify the species of leaves. Secondly, I found a yard with many trees and collected the leaves from the top, middle and bottom from three trees. The three species of trees are the radermachera, geranium and Osman thus. After that, I put the leaf samples in the plastic bags that labelled with the position and tree species. Then I traced each leaf on a piece of graph paper. I counted the number of squares that occupied by the leaves to figure out the area of the leaf samples and record them on the data table (see the table below).

Sun leaves are always lighter green than shade leaves. Shade leaves always contain greater chlorophyll and are darker green in color. In shade leaves, the chloroplasts move within the cells to take up the position where they will absorb the maximum light without shading other chloroplasts below them. The chloroplasts are evenly found between the palisade and spongy mesophyll layers in the leaves. On the other side, in sun leaves, the chloroplasts turn in the bright light and shelter in the shade of others when they make use of the light they have absorbed. Too much bright light would destroy the chlorophyll. In sun leaves, most of the chloroplasts are in the palisade