Suppose mendel breeds some true-breeding tall pea plants together with true-breeding short plants, to produce hybrid offspring (
all of which will be tall, because the tall allele is dominant). he then breeds those first-generation hybrid offspring together with more true-breeding short plants, to produce a new set of offspring.
There would still be a 50% chance for the offspring to be Heterozygous (Hybrid), but then there would be another 50% chance for the offspring to be Homozygous recessive (True-breeding short plants)
