What do you hypothesize is causing the bubble at the top?

From what you know about plants, if we were to place one of the test tube and beaker combinations in a dark closet, what would happen?

If we placed a green light (as opposed to white or natural light) in front of the test tube, do you think the results would be different? Why or why not?

What happened to the color of the solution over one hour?

Imagine that a giant meteor stuck the earth. When the meteor struck the earth it sent up a giant dust cloud that blocked out the sun for months. What would be the effect of this event on humans? Do you think that human life could survive for years without sunlight.