<span>If the parent's reproductive cells or gametes contain 12 chromosomes each, the number of chromosomes in the zygote is 24. Fertilization is the fusion of two haploid gametes and results in the creation of a diploid zygote. If two haploid gametes containing 12 chromosomes each fuse, the zygote will have 24 chromosomes (12 + 12 = 24).</span>
