Final answer:
Mendel's principle of segregation states that each individual possesses two alleles coding for a trait and that these alleles separate when gametes are formed. Each gamete carries only one allele for each gene.
Step-by-step explanation:
Mendel's principle of segregation states that each individual possesses two alleles coding for a trait and that these alleles separate when gametes are formed. Each gamete carries only one allele for each gene. This principle is explained by the process of meiosis, during which the chromosomes separate and each gamete receives only one allele for each trait.