Question

Leaves were collected from the plant of a certain species growing in a shaded site and a plant from the same species growing in an open site. The surface area of each leaf was worked out. The results obtained are shown in the table below.

Surface area of leaves (cm3)
Shaded site	Open site
21  14  16  18  19  21  19  22  18  16  13  22  21  23  19  18  15	15  17  18  17  17  19  13  14  21  13  16  13  16  12  14  22  20
Mean surface area = x1	Mean surface area = x2

1. Calculate the mean score x₁ and x₂ 
2. Suggest one reason for the differences in the mean surface areas between the leaves from the two sites. Explain your answer. 

Answer 1

1. X₁- sum of all surface areas = 18.53cm²
                          17
   X₂ – Sum of all surface areas =15.71cm²
                          17
2. the amount of light the leaves receive;
   • leave in shaded areas have larger surface areas to trap light of low intensity;
   • Leaves in open sites have smaller surface areas as light is of high intensity