fertilization is when an egg cell becomes fertilized
fertilization is enrichment. external_fertilization is egg_fertilization. self_fertilization is fertilization. egg_fertilization is not reproductive_fertilization. fertilization is creation. internal_fertilization_event is not egg_fertilization. self_fertilization is not fertilization. egg_fertilization is reproductive_fertilization. fertilization is not creation. external_fertilization is not egg_fertilization.