Eukaryotes can reproduce both asexually through mitosis and sexually through meiosis and gamete fusion. Dikaryotic cells result from the fusion of two haploid gamete cells. When mature, the haploid ovule produces the female gamete which are ready for fertilization. Thus, one of their gametes will combine with the gamete of another planarian. Fertilization is the event where the egg cell fuses with the male gamete, spermatozoon. The first being a female gamete, known as the ovum (egg/oocyte). In gamete production, interphase is succeeded by meiosis. They segregate (separate) during meiosis such that each gamete contains only one of the alleles. Embryo research is also allowed, gamete and embryo donation permitted on a commercial level. "Fertilization" is the fusion of both sex cell or gamete. In short a gamete is an egg cell (female gamete) or a sperm (male gamete). The cytoplasm, mitochondria and most organelles are contributions to the cell from the maternal gamete. A typical gamete (either egg or sperm) has one copy of each chromosome (23 total). In the event that an aneuploidic gamete is fertilized, a number of syndromes might result. The gonadotropins act on the gonads, controlling gamete and sex hormone production.