Mendel hypothesized that the two alleles segregate
(move apart) from one another during gamete formation.
From a heterozygote (Rr), two types of haploid
gametes formed. One type of gamete contains the
round allele (R), and one contains the wrinkled allele
(r). Homozygous individuals produce only one type of
gamete. Homozygous individuals with round seeds
(RR) would produce only gametes containing the round
allele (R), and wrinkled (rr) individuals would produce
only gametes containing the wrinkled allele (r).