In which of the following, the Mendelian genotypic monohybrid ratio is modified ?

D.Lethal gene – A gene usually results in the death of an individual when present in homozygous condition is lethal gene. Its ratio is 2:1. But the mendel monohybrid genotypic ratio, incomplete dominance genotypic ratio and co-dominance genotypic ratio are same as 1:2:1.