Photosynthesis: Pondweed and Dessert Leaf Experiment

 In a science lesson before the half term break, we did a practical lesson using pondweed and a lamp. Unfortunately, we didn't get the results we wanted because it was winter and our lamps were not powerful enough but we found an image that shows what should have happened. However, we had a much more successful experiment that shows how leaves can preserve more water.

Pondweed Experiment: The experiment is supposed to show how photosynthesis works with the lamp acting as the sun. The plant in the water is placed in next to the lamp and should make bubbles (oxygen leaving the plant as a result of photosynthesis) and as the lamp is put further away, the amount of bubbles the plant makes should decrease.

This photo is from our pondweed experiment where we have one bubble circled in red. We expected a lot more bubbles but at most; only had three.

How photosynthesis works is outlined in the following equation:

carbon dioxide + water, activated by light energy and chlorophyll = glucose and oxygen

6CO + 6H20 = C6H1206 + 602

Desert Leaf Experiment: This experiment shows how leaves have adapted to retain more water on very hot and bright days. When plants are placed in a hot and bright environment, they will  wilt and their leaves will curl up, this is because the plant is trying to preserve as much water as possible. Less surface area for the light source to hit means that the plant will retain more water which is why leave curl up and wilt during warmer weather. 

This photo was taken just after we had put the two "leaves" in water.

This photo was taken an hour later, the flat leaf was completely dry but the former, and curled up one, was still wet.