section_path: Branches of zoology/Reproduction
section_name: Reproduction
paragraph_text: Reproduction
  
  Animals generally reproduce by sexual reproduction, a process involving the union of a male and female haploid gamete, each gamete formed by meiosis. Ordinarily, gametes produced by separate individuals unite by a process of fertilization to form a diploid zygote that can then develop into a genetically unique individual progeny. However, some animals are also capable, as an alternative reproductive process, to reproduce parthenogenetically. Parthenogenesis has been described in snakes and lizards (see Wikipedia Parthenogenesis in squamates), in amphibians (see Wikipedia Parthenogenesis in amphibians) and in numerous other species (see Wikipedia Parthenogenesis). Generally, meiosis in parthanogenetically reproducing animals occurs by a similar process to that in sexually reproducing animals, but the diploid zygote nucleus is generated by the union of two haploid genomes from the same individual rather than from different individuals.