Fig. 1
From: Mendel’s pea crosses: varieties, traits and statistics
Frequency distribution of segregation ratios. The number of dominant homozygotes (AA) in the F2, m (x axis), among 100 F2 individuals of the dominant class (AA and Aa) (Additional file 1: Table S1.3) is plotted against the frequency with which this number is expected to occur. This frequency corresponds to the likelihood, Lm, (y-axis) with which that number occurs as determined by the binomial distribution; these values were obtained in Excel using the function BINOM.DIST. The values that Mendel obtained are ringed and the gene involved is indicated, see Ellis et al. [13] for an explanation of the gene symbols. The upper panel is the frequency expected given a 1: 2 ratio, and the lower panel is the frequency distribution based on Fisher’s ratio