Reproduction is a characteristic of all living beings. It is fundamental to the maintenance of the species, since, under the present conditions of the earth, living beings arise only from other living beings like them through reproduction.
At the molecular level, reproduction is related to the unique ability of DNA to duplicate. As we have seen, it is the chromosome DNA that commands and coordinates the entire process of cell division.
There are several types of reproduction that living beings have, but they can all be grouped into two broad categories: the reproduction asexual and the sexual.
Individuals who arise by asexual reproduction are genetically identical with each other, forming what is called a clone. These individuals will have different genetic heritage only if they undergo gene mutation, that is, alteration in the nitrogen base sequences of one or more DNA molecules.
There are many living beings that reproduce asexually and several are the types of asexual reproduction.
In eukaryotes, unicellular or multicellular, asexual reproduction is related to mitosis.
In the case of unicellular, the type of asexual reproduction that allows them to split into two is called bipartition.
The bipartition process also occurs in prokaryotes, but in this case there is no mitosis like that found in eukaryotes.
In multicellular organisms such as plants, for example, asexual reproduction can occur by vegetative propagation. In this case, parts of the plant may give rise to other individuals through mitosis.
Knowing these peculiarities of plants, the human being learned to make use of it, for their own benefit, making seedlings, which cultivated, give rise to the new identical plant, the mother plant, thus preserving the commercially important characteristics.
In animals, one of the most frequently observed types of asexual reproduction is budding or twining: From an initial individual springs another individual, who can stand out from the first and have an independent life. This is what happens, for example, in hydra. In other cases, budding can give rise to a colony of organisms, in which buds remain attached to the initial individual and develop attached. This is what happens in most sponges. Hydra, an aquatic organism, is an example of an animal that exhibits this type of reproduction.