____________________, also called conception, occurs when the sperm and egg nuclei combine
Gametes have a haploid number (23). When conception occurs, a human sperm and ovum combine their chromosomes to make a zygote (fertilized egg) with 46 chromosomes. This is the same number that the parents each had in their somatic cells. In doing this, nature is acting conservatively. Each generation inherits the same number of chromosomes.