Practice question

Cortical granules are membrane-bound dense core secretory organelles positioned beneath egg plasma membrane, synthesized during oocyte growth via Golgi cisternae producing condensing vacuoles loaded with proteases, ovoperoxidase, hyaline, and sulfated glycosaminoglycans. Their biogenesis, acidic pH, lysosomal hydrolase content, and calcium-triggered SNARE-mediated exocytosis parallel sperm acrosomal vesicles, making them egg equivalents of acrosomes. Both belong to regulated secretory lysosome lineage bearing mannose-6-phosphate receptors. Ribosomes perform translation, nuclei contain chromosomes, and other organelles lack regulated exocytosis machinery, explaining why cortical granules are considered homologous to acrosomal vesicles rather than housekeeping organelles.