Start studying lab 16 corn genetics quiz and lab learn vocabulary terms and more with flashcards games and other study tools. The epistatic gene typically controls the production of a precursor to the end product recessive epistasis the dominant allele for the epistatic gene creates a product that actively blocks the production of the end product so a single dominant copy will create the altered phenotype for the affected genes dominant epistasis. Start studying lab 10 genetics of corn learn vocabulary terms and more with flashcards games and other study tools. If the gene pair contain the same alleles bb or bb heterozygous if the gene pair contain different alleles bb also called hybrid dihybrid cross a dihybrid cross is a cross between two parent organisms that are homozygous for different forms if two traits produces off spring that are heterozygous in both traits. The corn we used is the product of a this means that the parent plants carried both a dominant and recessive gene for color and form ppss chi square test the will show whether sample is different from the expected ratios and will tell us whether to accept or reject the null hypothesis