reproduction | reproductive process | fertilization | single fertilization | sexual reproduction
secretory granule | intracellular membrane-bounded organelle | cytoplasmic vesicle | cell | vacuolar lumen | cytoplasmic vesicle lumen | cytoplasm | acrosomal vesicle | intracellular organelle | secretory vesicle | endomembrane system | vacuole | vesicle | lytic vacuole | membrane-bounded organelle | organelle | lysosome | membrane-enclosed lumen | lysosomal lumen | secretory granule lumen | intracellular vesicle | acrosomal lumen | intracellular | vesicle lumen