title: Penetration of human eggs by human spermatozoa in vitro.
mesh_terms: D000177:Acrosome / Q000648:ultrastructure; D005260:Female; D005307:Fertilization in Vitro; D006801:Humans; D008297:Male; D010063:Ovum / Q000648:ultrastructure; D013084:Sperm-Ovum Interactions; D013094:Spermatozoa / Q000648:ultrastructure; D013997:Time Factors; D015044:Zona Pellucida / Q000648:ultrastructure