Among the following phenotypes which can be determined as true breeding line with respect to the trait that it has

Red flowered snapdragon plant has the genotype RR and it is true breeding for flower color. Pink flowered Snapdragon is not true breeding line as it is heterozygous with the genotype Rr. An individual with A blood group may homozygous (true breeding) with genotype IAIA or heterozygous with genotype as IAIO. Pea plant with Axillary flowers has the genotype AA (homozygous) or Aa (heterozygous).