Practice question

Cross between homozygous tall TT and dwarf tt parental lines provides only one allelic type per parent, T from tall and t from dwarf. Fertilisation yields uniform F1 progeny receiving T and t, genotype Tt. Because tall allele exhibits complete dominance, heterozygous phenotype resembles tall parent, dwarf allele phenotypically silent though carried. No dwarf appears, no 1:1 or 3:1 segregation yet, tall dominance explains uniformity. If tall were recessive or linked distortion expected alternate ratios, observed uniformity confirms dominance relationship. Conceptual clarity supports solving numerical problems involving segregation ratios, recombination frequencies and probability calculations in crosses.