The law of segregation states that allele pairs separate during gamete formation. How then do we have two alleles for a trait? W
e receive one allele from each parent. The alleles join back together before traits are inherited. We receive the two alleles at separate times from one parent.
We have two alleles for a particular trait even though the allele pairs separate during gamete formation as per the law of segregation. It happens because at the time of fertilization when each parental gamete which is haploid in nature fuse to form a diploid totipotent cell which is known as zygote. Formation of zygote restores the diploidy so that the off springs of these parents have two alleles for each trait. The two alleles of a trait segregate by the process of meiosis (a type of cell division) which occurs in germ cells at the time of gamete formation.
