How can test cross decipher the heterozygosity of a plant?
This cross determines whether the dominant character is coming from homozygous dominant genotype or heterozygous genotype (e.g. tallness coming from TT or Tt). When TT is crossed with tt, we obtain all Tt (tall) individuals in the progeny, whereas when Tt is crossed with tt, we obtain Tt (tall) and tt (dwarf) individuals in the progeny. Thus, a test cross can be used to determine the heterozygosity of the plant.