Here's why:

* Two copies of each gene: Mendel's Law of Segregation states that individuals inherit two copies of each gene, one from each parent. These copies are called alleles.

* Donate one copy to offspring: During the formation of gametes (sperm and egg cells), these two alleles separate, and only one allele from each pair is passed on to the offspring.

This principle forms the basis of how traits are inherited from parents to offspring.