Akanksha Soni, Academic Content Writer at Edumarz
Fission:-
It is a method of asexual reproduction.
In this process a single parent cell divides into two or more daughter cells. These daughter cells develop into a new organism .
It occurs mainly in unicellular organisms such as amoeba, bacteria, leishmania,plants, sea stars, planaria, molds and spirogyra etc.
Nuclear division takes place in this method.
According to the formation of daughter cells, fission can be classified as binary fission and multiple fission.
Binary fission:- In this method the parent cell produces two daughter nuclei by the process of cytokinesis. These daughter cells develop into a new organisms. It is the main method of reproduction in bacteria by the process of mitosis.
Example:- Amoeba and Leishmania ( Kala-azar ) etc.
Multiple fission:– In this method the nucleus is divided several times by the process of mitosis and later cytokinesis . As a result, several daughter cells arise that are genetically identical. It occurs mainly in protists such as sporozoans and algae. It can also happen in bacteria.
Example:– Plasmodium.
Fragmentation:–
It is also known as clonal fragmentation or colonial organisms.
Fragmentation is a method of asexual reproduction.
It occurs mainly in multicellular organisms such as plants , sea stars, planaria, molds, spirogyra, sponges, annelids, and acoel flatworms etc.
In this method the parent organisms is broken into smaller pieces or fragments, each fragments capable of producing new organisms.
These are the main methods of vegetative reproduction in plants by which they produce rhizomes, stolons, bulbils, adventitious plantlets etc.
It increases the members of that particular colony.
The mechanism of fragmentation in animals is paratomy and achiotomy.
Paratomy is the method of splitting perpendicular to the antero-posterior axis.
Achitomy is the method of splitting at the particular point from which the missing tissues and organs regenerate.
No nuclear division takes place during fragmentation.