Photosynthesis Lab:
Pre-lab reading:
The picture above shows all the forms of radiation that are sent to Earth from the sun. Visible light, what you see, is only a fraction of what the sun emits. The other forms of radiation are invisible such as ultraviolet light and infrared, meaning you can't see them with your eyes. Imagine if the sun didn't send visible light, it would be a very dark world. As you can see, visible light is all colors of the rainbow (i.e. red, yellow, green, blue, etc.). When visible light hits a plant, the plant uses the light to make sugar through the process of photosynthesis, but do plants use all colors of visible light to power this reaction? In this lab we will discover if plants have a preference for light color as evidenced by increased plant growth. The idea is that if plants are put under a desirable light color, they will perform more photosynthesis reactions, make more sugar, and have more matter and energy to grow in size. Conversely. if plants are put under an undesirable light color, they will perform less photosynthesis reactions, make less sugar, and have less matter and energy to grow.
Step 1: What form of radiation is sent from the sun that we can see?
Step 2: Why is visible light important for plant growth?
Step 3: You will test five light colors (i.e. Red, Violet, Blue, Green, and Orange) separately on plants. What color do you think will make the plants grow taller? (Hint: This is technically your hypothesis).
Step 4: Click on the video of the lab here. Normally you'd do the lab yourself, but it can no longer be accessed. As you watch the video, observe what's happening and record results in performance task.
Step 5: What color(s) of light did plants prefer for photosynthesis? How could you tell?
Step 6: Did your data support your hypothesis? Why do you think it did or did not?