In Mendel's law of segregation as applied to a monohybrid cross, what happens to the two alleles for a gene during gamete formation?

• A. Allele pairs separate during gamete formation, so each gamete carries one allele
• B. Alleles pair up and stay together in the same gamete
• C. Both alleles are transmitted to every gamete
• D. New allele variants are created during gamete formation

Answer: (A)

During gamete formation, the two alleles for a gene separate into different gametes. This happens as homologous chromosomes separate during meiosis, so each gamete ends up with only one copy of the gene, carrying just one allele. In a monohybrid cross, a heterozygous parent (Aa) produces two types of gametes: one with the A allele and one with the a allele. Fertilization combines alleles from two parents to restore the diploid genotype in offspring. The alleles aren’t created anew during gamete formation, and they don’t both go into the same gamete or stay paired together.