Multiple choice An unfertilized human egg contains one Y chromosome one X chromosome two X Chromosomes one X and one Y chromosome Reveal answer Fill a bubble to check yourself B Correct answer Explanation Human females have two X chromosomes (XX), while males have one X and one Y (XY). An unfertilized egg (ovum) always contains one X chromosome from the mother. Sperm can carry either X or Y chromosome, determining the baby's sex.