Practice question

In monohybrid test cross, heterozygote Tt crossed to homozygous recessive tt yields tester gametes all t, while Tt produces T and t in equal proportion after segregation. Random union creates equal numbers of Tt tall and tt dwarf progeny, phenotypic ratio 1:1. This demonstrates genotype of tested parent, reveals gamete diversity and allows estimation of segregation without dominance confusion. Ratio 3:1 arises from heterozygote selfing, 1:2:1 genotypic self ratio, 9:3:3:1 dihybrid cross, test cross uniquely gives 1:1 phenotypic expectation. Mastery ensures accurate interpretation of monohybrid and dihybrid progeny arrays, distinguishing dominance interactions from epistasis or linkage effects.