State Mendel’s Law of Segregation.

• A. Alleles segregate during fertilization; offspring receive two alleles from each parent.
• B. Gametes contain full sets of chromosomes.
• C. Alleles segregate during gamete formation, so offspring receive one allele from each parent.
• D. Genes are transmitted as linked units.

Answer: (C)

Alleles separate during gamete formation. During meiosis, the two copies of a gene on homologous chromosomes segregate so each gamete receives only one allele for that gene. When fertilization occurs, the offspring get one allele from each parent, restoring two alleles for that gene in the zygote. This explains why a trait can skip generations and reappear in offspring.

The other ideas don’t fit because gametes carry only one set of chromosomes (haploid), not full sets; and segregation happens during gamete formation, not fertilization. The notion of genes as linked units describes linkage, not the separation of alleles during gamete formation.