Science Buddies: "Ask an Expert"

How do you make a graph about the chlorophyll content of leaves? For my presentation, I need to have a graph about my science experiment. The project is about how color affects the chlorophyll content of the leaf, in the experiment I don't measure anything but I need to make a graph on something (there is no exceptions for not having a graph). So how can I make a graph when the experiment is based on appearance?

Hi Ayen,

Can you tell us briefly how you're setting up your experiment? Are you growing plants under lights of different colors and then observing them qualitatively (i.e. no numbers) to look for differences? I would recommend creating a numerical color scale where a low number corresponds to brown/yellow (not very green) and a high number means very green. Here is an example that I found by searching "green leaf color scale" in Google images: http://tinyurl.com/pl6f3y2

You could assign each plant an approximate value based on this scale at the end of the experiment, then name your different conditions on the x-axis and plot each corresponding number on the y-axis as a bar graph. Alternatively, if you make observations every few days, you could plot the leaf color values over time, which might be interesting. In that case, each condition could be plotted as a different color or symbol (sort of like this: http://tinyurl.com/oyrov2s).

Hope that helps!
Megan