ABSTRACT
The obvious next step is to look at a situation where the inheritance of two different inherited characters are studied at the same time, a dihybrid cross. The simplest experimental system for this is to cross two pure-breeding strains of a species, one of which is homozygous for recessive alleles of two genes and the other homozygous for dominant alleles of the same two genes. Again Mendel was the first to carry out such experiments. In one of these he used pea plants that differed in two properties of the seed.
