title: Insemination of immature sea urchin (Arbacia punctulata) eggs.
mesh_terms: D000818:Animals; D002467:Cell Nucleus / Q000648:ultrastructure; D002843:Chromatin / Q000648:ultrastructure; D003594:Cytoplasmic Granules / Q000648:ultrastructure; D004721:Endoplasmic Reticulum / Q000648:ultrastructure; D005260:Female; D005306:Fertilization; D008297:Male; D008540:Meiosis; D009865:Oocytes / Q000648:ultrastructure*; D009866:Oogenesis; D010063:Ovum / Q000648:ultrastructure*; D012617:Sea Urchins; D013084:Sperm-Ovum Interactions; D013094:Spermatozoa / Q000648:ultrastructure*
chemical_list: D002843:Chromatin