one parent is the source of 50% of the genes in a fertilized egg through sexual reproduction
sexual_reproduction is biological_reproduction. pollination is not fertilization. stratifying is reproductive_fertilization. biological_mother is parent. offspring is product_of_sexual_activity. egg_fertilization is not reproductive_fertilization. pollination is fertilization. biological_mother is not parent. egg_fertilization is reproductive_fertilization. stratifying is not reproductive_fertilization.