is the fusion of two haploid sex cells (sperm and egg) to form a diploid cell
Making the world better, one answer at a time. The fusion of two haploid gametes to form a new diploid cell is called fertilization. Self-fertilization in plants, the fusion of two gametes from the same individual to form a diploid offspring.aking the world better, one answer at a time. The fusion of two haploid gametes to form a new diploid cell is called fertilization. Self-fertilization in plants, the fusion of two gametes from the same individual to form a diploid offspring.