Asexual reproduction utilizes the genetic material from only one parent. It occurs throughout nature in both plant and animal species. In some species it is the regular method of reproduction, while in others it is done in emergency or otherwise special circumstances. Asexual reproduction occurs in multiple ways to produce a myriad of offspring. In some instances, the offspring become exact copies of the parent, while in other cases, they experience changes that mark them as different.
TL;DR (Too Long; Didn't Read)
Asexual reproduction includes methods such as budding, where the offspring develops as a growth on the parent's body; binary fission as a form of cell division; fragmentation, where parts of the parent's body breaks away to form a separate entity, parthenogenesis, which essentially is an egg that develops without outside fertilization and apomixis, which occurs in plants where embryos grow from egg cells without pollen fertilization.
Commonly seen in parasitic animals such as tape worms, budding involves the offspring developing as a growth on the parent's body. While some species can grow these buds anywhere, others only form them in specialized anatomical areas. Bacteria, yeast, protozoans, coral and even jellyfish use budding as a regular method of reproduction. In the case of animals such as jellyfish, the young eventually break off from the parent and become independent, while with organisms such as coral they stay attached their entire lives, becoming part of coral colony.
Breaking Apart -- Fragmentation
Often employed by worm species, fragmentation is an asexual reproduction method that entails the parent animal growing to maturity then breaking up into multiple small pieces. These pieces grow into mature worms as well, and then the process starts over again. The offspring are all genetic duplicates of the original parent animal.
The Virgin Birth -- Parthenogenesis
Also known as virgin birth in biology, parthenogenesis entails a female plant or animal producing viable eggs without the aid of a male to fertilize them. It is seen in some species of fish, insects, frogs, lizards, invertebrates and plants, as a regular form of reproduction or an emergency method.
Mammals rarely use this method unless some form of scientific manipulation happened to them, such as mice in laboratory settings. The sex cell known as a gamete, produced from parthenogenesis is usually female, but certain environmental situations can produce male gametes as well.
Other Asexual Reproduction Methods
Apomixis is a type of asexual reproduction found in plants, where embryos grow from egg cells without first being fertilized by pollen. Binary fission is an equal and direct division of the cytoplasm and nucleus in an organism, which leads to the formation of two identical organisms.