Figure 2.

The currently favoured depiction of Mendelian inheritance following self-fertilisation of F1 hybrids represented by the allele pair (Aa). Section 3.1 of the text records the arguments commonly used in attempts to account for the alleged F2 trait series (AA + 2Aa + aa) and for Mendel's 3(dominant):1(recessive) trait ratio. Sections 3.2 and 3.3 discuss the faults in these arguments.