Regeneration is a method where an organism breaks up into different parts with the help of special cells. It refers to the capacity of the organisms to generate damaged or lost body parts. Here each of the parts can also further produce individual organisms. In the case of regeneration, the organisms are not able to form a new cell suddenly. Instead of this, the specialised cells form a mass of cells and it is changed further to create different cells.

Figure 1: Regeneration in Planaria

Information regarding Regeneration

Regeneration is considered to be a natural process and it describes the concept of restoring or replacing missing or damaged cells, organs, and tissues. The process also includes the repairing of full body parts for functioning animals as well as plants.

Figure 2: Use of Regeneration to Repair Myelin in Humans

The researchers also analyse the human ageing process through the studies of regeneration. The process of regeneration happens in sequence as well as in an organised manner which is known as differentiation. It is seen that although there are some similarities between the concepts of regeneration and reproduction, they are not the same process.

Regeneration is a process like asexual reproduction and it can be involved in forming new organisms from a single organism. But most organisms do not wait for breaking into pieces or to be cut for the process of reproduction. That is the reason it is said that regeneration is not the same as reproduction.

Different types of Regeneration

The process of regeneration is mainly classified into two parts and they are −

  • Morphallaxis and

  • Epimorphosis


Morphallaxis is considered to be the type of regeneration process having little growth. The matter also depends upon the repatterning of the tissues. An example of this factor is Hydra and it is seen that the growth of the hydra happens with the loss of cells from its end and by budding. The observation regarding this process is that when it is cut into two pieces, the upper part develops a foot while the lower part develops a head.

On the other hand, it is seen that Epimorphosis is the regeneration that depends upon the growth of new and properly patterned structures. Here the regeneration process of a vertebrate limb is considered to be an example of this factor. The process mainly involves growth as well as the dedifferentiation of cells. The cells of epidermal create blastema and here the blastema gives rise to structures.

Which Organisms can Regenerate?

Here it is seen that different organisms are able to regenerate and the process happens in some organisms like tapeworms, flatworms, and hydra. They are capable of highly adaptive regeneration and it is an important part of their life cycle. The activation of the cells happens when an organism is wounded and thus the damaged cells are remodelled back to the original state.

It is a prominent factor for the metazoans as well as reptiles, amphibians, crayfish, and starfish. The process is different from the process of reproduction and it can be performed in many ways using pluripotent stem cells. The process of regeneration for some organisms does not require stem cells.

Regeneration in Plants and Hydra

Regeneration is an essential concept for plants and it is seen that plants are able to regenerate all body parts from the precursor cells. Examples of this process are seen when trees are seen cut off at the bottom. They are observed to sprout after some time. Then they mature into new leaves, flowers, and stems. It is also seen that the plants mature into a new plant by callus differentiation in the laboratory through plant tissue culture.

Figure 3: Regeneration of Hydra

Hydra is considered to be the mostly used model for the process of regeneration. It is used for examination since time immemorial and it is seen that when it is cut into two pieces, it starts to regenerate. The wounded cells start to regenerate and then it is transformed into the pre-existing cells.

It is seen that the growth of hydra happens by continuously losing cells from its base and by budding. After that, a gradient of inhibitor is produced by the head and it mainly prevents the creation of other heads. Then it is seen that the concentration of inhibitor is reduced. The value of the position of the factor is increased and the growth of the new head is seen.


Regeneration is an important process and it differs from the process of reproduction. Hydra is the most important organ that helps in the examination of this process. The tutorial shows regeneration as repairing of cells and the process of giving birth to new individual cells. The tutorial also represents two types of regeneration and they are morphallaxis and epimorphosis. There are different organisms that can regenerate such as the starfish, reptiles, amphibians, hydra and many more.


Q1. Are humans capable of regeneration?

Ans. The process of regeneration also happens in humans such as the skin that is renewed from time to time. It is also seen that when some of the parts of the liver get damaged, it also regrows after some time. That is the reason regeneration is called an integral part of healing.

Q2. Who is capable of regeneration?

Ans. Some organisms able to regenerate include hydra, flatworms, and tapeworms. Some metazoans are able to do this process like starfish, crayfish, reptiles, and amphibians.

Q3. How many types of regeneration can be seen?

Ans. Two types of regeneration can be seen and they are morphallaxis and epimorphosis. Some regeneration depends upon tissues repatterning and some depend upon structures.

Updated on: 13-Apr-2023


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