An overview of the structures inside a sperm cell: Acrosome: This cap-like vesicle contains hydrolytic enzymes which are released to help the sperm penetrate the protective layers surrounding the egg during fertilization. Nucleus: Located in the head of the sperm, the nucleus carries the haploid set of 23 chromosomes (the paternal genetic material) that will combine with the egg's DNA. Centriole: The two centrioles in the neck of the sperm play a critical role in forming the axoneme of the tail