the data are plotted in a type of graph called a histogram, which groups values for a numeric variable on the x-axis into intervals. a histogram allows you to see how an entire group of experimental subjects (cells, in this case) are distributed along a continuous variable (amount of fluorescence). in these histograms, the bars are so narrow that the data appear to follow a curve for which you can detect peaks and dips. each bar represents the number of cells observed to have a fluorescence level in that interval. this in turn indicates the relative amount of dna in those cells. which axis indirectly shows the relative amount of dna per cell? by what relationship?