Reproduction

There are several ways animals can produce offspring. The two main methods of reproduction are sexual and asexual. Sexual reproduction requires two parents who donate genes to the young, resulting in offspring with a mix of inherited genes. In asexual reproduction, only one parent is needed, resulting in offspring that are genetically identical to the parent -- clones. Let's examine the different types of asexual reproduction.

Asexual Reproduction

The three main ways that asexual reproduction can take place are by fission, fragmentation, and regeneration. In fission or budding, one or more individuals are formed from an original. These new clones can either remain attached physically to the parent or break away from it. Stony corals commonly exhibit this type of reproduction.

Gemmules, a type of internal budding, allow an organism to survive under drastic conditions. Sponges exhibit this type of reproduction.

Fragmentation is another way to reproduce asexually. The parent breaks into different fragments, which eventually form new individuals. This process is exemplified by certain flatworms known as planarians.

In regeneration, when an animal that is capable of regeneration loses a body part, it can grow a replacement part. If the lost body part contains enough genetic information from the parent, it can regenerate into an entirely new organism. Echinoderms are examples of animals that use regeneration.

Advantages of Asexual Reproduction

Asexual reproduction can be very advantageous to certain animals. For instance, animals that remain in one particular place and are unable to look for mates would need to reproduce asexually. Another advantage of asexual reproduction is that numerous offspring can be produced without "costing" the parent a great amount of energy or time. Environments that are stable and experience very little change are the best places for organisms that reproduce asexually. The cloned offspring are more likely to succeed in the same stable areas as their parents.

For additional information on reproduction see:

Asexual Reproduction

Sexual Reproduction