The relative frequency of two phenotypes in a species of snail is illustrated through the following:

1. A picture of snails, in which few are without band and rest having bands on their shell.
2. A bar graph captioned 'Single-Gene Trait' with x-axis representing the 'Phenotype' and y- axis representing 'Relative Frequency of Phenotype (in percent)' ranging from 0 to 100 in increment of 20. 'Without bands' bar height is 22 and 'With bands' bar height is 78.