In a monohybrid cross involving two heterozygous parents (Aa x Aa), the offspring can exhibit three genotypes: homozygous dominant (AA), heterozygous (Aa), and homozygous recessive (aa). The expected genotypic ratio from this cross is 1 AA : 2 Aa : 1 aa, which simplifies to 1:2:1. This ratio reflects the distribution of alleles during gamete formation and fertilization according to Mendelian inheritance principles.