explain how the alleles were passed from parents to offspring.

Brief Explanations:

Alleles are passed through the process of meiosis in parents which forms gametes. Gametes from each parent combine during fertilization. Each parent contributes one allele for each gene to the offspring.

Answer:

Alleles are passed via meiosis - gamete formation in parents and then fertilization where gametes combine, with each parent contributing one allele per gene to the offspring.