title: An ultrastructural analysis of early fertilization in the sand dollar, Echinarachnius parma.
mesh_terms: D000818:Animals; D002466:Cell Nucleolus; D002467:Cell Nucleus; D003594:Cytoplasmic Granules; D005260:Female; D005306:Fertilization; D005407:Flagella; D002479:Inclusion Bodies; D008055:Lipids; D008297:Male; D008854:Microscopy, Electron; D008928:Mitochondria; D009940:Organoids; D010063:Ovum / Q000166:cytology*; D010860:Pigments, Biological; D012617:Sea Urchins / Q000166:cytology / Q000502:physiology*; D013094:Spermatozoa / Q000166:cytology*; D014817:Vitelline Membrane / Q000166:cytology
chemical_list: D008055:Lipids; D010860:Pigments, Biological