Science Buddies: "Ask an Expert"

hi, I'm doing the project: Biowarfare: Experiment with Viruses that Destroy Bacteria and we need to turn in the procedures and graph tomorrow but I don't know which graph to use. Would it be a line graph? also what would the independent and dependent variable be?

Hi there,

I'm sorry if this response is too late!

The independent variable is the thing you change, and the dependent variable is the thing you measure in response to the changed thing. Here, the independent would be the starting phage concentrations, and the dependent would be the number of plaques counted. With this data type, you could use a line graph, bar graph, or scatterplot. It's up to you to decide what would show the data most sensibly; I think a line graph would work well.

–Eugene

(this is for my graph) the independent variable should by the phage concentration but don't really understand what the phage concentrations are. do I put the dilutions as the independent variable?? im. so. confused. as to what my graph should look like PLEASE ANSWER SOON

Hey! So it is probably too late, but just in case it isn't, the phage concentration is the concentration of the virus that can infect the bacteria and archaea. I am not sure what your experiment entails, but you mentioned a dilution which is also a concentration, so I would assume the dilution(s) you found (or were given) would be the independent variable since it is a concentration. If that is so, your values for the different concentrations would be on the x axis (independent=x, dependent=y). The number of plaques would be on the y axis because that is what you are measuring. If you are given data points, plot them according to the x and y values and connect the dots to form your graph. Hope this helps!