How many copies of genes do parents pass on to their offspring?

Parents pass on two copies of each gene to their offspring, one from each parent. This is a fundamental principle of genetics known as Mendelian inheritance. Each parent carries two alleles for each gene (one on each of their homologous chromosomes) and contributes one allele to their offspring during the formation of gametes through a process called meiosis.

When gametes are formed, the alleles segregate, ensuring that each gamete receives only one allele for a given gene. This means that once fertilization occurs, the resulting offspring will inherit one allele from the mother and one allele from the father, consequently totaling two alleles for each gene present. This genetic principle is crucial for understanding how traits are passed down through generations, and it forms the basis for predicting inheritance patterns in offspring.