Science Skills
A student prepared two beakers with identical sprigs of a water plant as shown below. She placed one beaker in
the shade and the other beaker beside a fluorescent lamp. She then systematically changed the distance from the
beaker to the lamp. She counted the bubbles given off by the plants in each beaker. Shown here is the graph of the
data for the beaker she placed beside the lamp.

If the student later tested the bubbles collected in the test tube, what would she find they are made of?