* True-breeding organisms are homozygous for a specific trait. This means they have two identical alleles for that trait.
* Recessive alleles only express their trait if an individual has two copies of that allele (homozygous recessive).
* When two true-breeding organisms with contrasting traits are crossed (for example, one homozygous dominant for purple flowers and one homozygous recessive for white flowers), the F1 generation will all inherit one dominant allele and one recessive allele. This makes them heterozygous.
* Since the dominant allele masks the recessive allele in heterozygotes, the F1 generation will exhibit the dominant trait, in this case, purple flowers.
Therefore, the F1 generation of true-breeding organisms will express the dominant trait, not the recessive trait.
