title: The ultrastructure of knobbed bull spermatozoa.
mesh_terms: D000177:Acrosome / Q000648:ultrastructure; D000818:Animals; D002417:Cattle; D002418:Cattle Diseases / Q000473:pathology*; D007248:Infertility, Male / Q000473:pathology / Q000662:veterinary*; D008297:Male; D013094:Spermatozoa / Q000648:ultrastructure*