Chromosomes normally occur as homologous pairs in:
A. a zygote.
B. a gamete.
C. an egg cell.
D. a sperm cell.
A zygote is the fertilized egg, formed by the union of the sperm and egg cells. Each sex cell, or gamete, provides the new cell with half of the needed genetic material. This genetic material, the chromosomes, now completes the new cell (zygote) with homologous pairs.