Asexual reproduction is when reproduction only requires 1 parent and the offspring are exact replicas as the parent. Organisms that reproduce asexually do not have much diversity because they are just a clone of the first. There are 4 methods of asexual reproduction. These methods are binary fission, budding, fragmentation, and parthenogenesis. SIngle celled organisms which use asexual reproduction usually do so by splitting in half, this is called binary fission. Budding is when the offspring grows out of the parent. For example yeasts, the offspring grows on the parent. Fragmentation is when the parent breaks into distinct pieces each of which grows into an offspring. Some plants are grown by planting cuts of the plants. Many plants are very advanced in their method of reproduction, offspring can be created by runners, bulbs, rhizomes, or tubers. Parthenogenesis is when females create eggs that develop without needing fertilization. Parthenogenesis occurs naturally in some invertebrates, along with several fish, amphibians, and reptiles and sometimes in plants. There is no known mammal that uses parthenogenesis.