Leaf Lab Report Re-write PDF

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MANDATORY ASSIGNMENT, LAB REPORT...

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Maribel Espinoza Emily Pavia September 21st, 2017 Bio Lab

Sunlight’s Effect on Leaf Size Introduction Sunlight is a very important factor in a plant’s life because it gives it energy to survive. We conducted an experiment to see whether or not sunlight would have an effect on a leaf’s size. This is also known as phenotypic plasticity, where the physical appearance of an organism can change based on the environment. The purpose of this lab was to see if the width of a leaf has any relation to whether or not the leaf is in sunlight or in shade. My hypothesis for this lab was that the leaves in the sun will be wider than the ones in the shade. The reason I believe this was true because plants produce food through a process called photosynthesis, which can help give them energy and grow more. Methods To complete this lab as a group we needed to pick 25 leaves from an area where the leaves were in the sun the majority of the day and 25 leaves in an area where the leaves were mostly in the shade on campus. In order to get accurate data we needed to move down the bush from the right to the left and picked leaves at random. We also stuck our hand out to pick one completely random. To measure the width of each leaf we used vernier calipers and when measuring each leaf we measured at the center where it is widest. To test our data we did a TTest. To record our data and test it, we used Excel. Results The average leaf width and standard deviation for the high-light group was 41.1 +/- 8.35 (+/- SD) and the average and standard deviation for the low-light group was 46.5 +/- 6.83 (+/SD). Our P-value was 4.13 * 10^-6 (Figure 1).

Figure 1. This graph compares the averages of the size of two groups of leaves. Error bars represent the standard deviations of the mean.

Discussion After collecting and analyzing our data we concluded that the leaves in the low-light group are significantly larger than leaves in the high-light group. Since our P-value was 0.00000413 which is smaller than 0.05, it means that there is a significant difference between our groups. This also means that our null hypothesis can be rejected. My original hypothesis was that leaves in the high-light would be bigger than those in the low-light but this was not true. This could be because the leaves that are in the sunlight can be shrunken down....