This experiment provides a low cost solution for investigating the rate of photosynthesis for students who are blind or visually impairedI. It could also be used with sighted students.
A common experiment when studying plant biology is investigating factors affecting the rate of photosynthesis. Plants produce oxygen which is invisible and odorless, so the experiment is usually carried out with water plants; the bubbles of oxygen produced are observed. The experiment is usually carried out with a common pond weed, and sighted students are instructed to count tiny bubbles: the faster the rate of bubble production, the faster the rate of photosynthesis.
This presents a problem for students with VI since the bubbles are often too small to see and therefore counting them and gathering valid results is not possible. A typical arrangement is shown in the photo on the top right, with a lamp and a beeker of water with pondweed in it.