What is the Difference Between Fragmentation and Regeneration

The main difference between fragmentation and regeneration is that the fragmentation is the breaking out of a parent organism into several pieces, each developing into a new organism whereas regeneration is the regrowth of a broken part of an organism. 

Fragmentation and regeneration are two types of growth that occur in organisms. However, fragmentation is a method of asexual reproduction while regeneration is not a method of reproduction.

Key Areas Covered

1. What is Fragmentation
     – Definition, Facts, Types, Examples
2. What is Regeneration
     – Definition, Facts, Types, Examples
3. What are the Similarities Between Fragmentation and Regeneration
     – Outline of Common Features
4. What is the Difference Between Fragmentation and Regeneration
     – Comparison of Key Differences

Key Terms

Achitomy, Asexual Reproduction, Epimorphosis, Fragmentation, Morphallaxis, Paratomy, Regeneration

What is Fragmentation

Fragmentation is an asexual reproduction method which occurs in multicellular organisms. It occurs in animals such as sponges, annelids, and flatworms. It also occurs in plants, molds, lichens, filamentous bacteria. In colonial organisms, it is called colonial fragmentation. In higher plants, it serves as a vegetative reproduction method. Rhizomes, bulbils, stolons, and adventitious plants serve as fragments that can develop into new plants. The genetics of new organisms is exactly the same as the parent organism. In lower plants such as Spirogyra, which are the green, filamentous algae in ponds can break down into parts mechanically and each part can develop into a new organism.

Figure 1: Fragmentation through Plantlets

The two main methods of fragmentation are paratomy and achitomy.

• In paratomy, the fragmentation of organism occurs perpendicular to the antero-posterior axis.
• In achitomy, the regeneration of the missing organs and tissues occur from the point of fragmentation.

What is Regeneration

Regeneration is the reactivation of development in order to restore the missing tissues. It occurs through three methods. They are epimorphosis, morphallaxis, and compensatory regeneration.

• In epimorphosis, the undifferentiated mass of cells is formed by the dedifferentiation of an adult structure, which is then developed into the missing tissue. The regeneration of salamander limbs occurs in this way.
  

  Figure 2: Regeneration of the Tail of Dwarf Yellow-Headed Gecko

• In morphallaxis, repatterning of an existing tissue is responsible for the development of the missing part. But here, only a small portion can be regenerated. It occurs in Hydra. The regeneration of blastema occurs through pattern formation.
• In compensatory regeneration, through the cells are divided to regenerate the missing tissue, these cells remain in their differentiated nature. The mammalian liver can be regenerated in this way.

Similarities Between Fragmentation and Regeneration

• Fragmentation and regeneration are two methods used by organisms to grow their body.
• Both occur in multicellular organisms.
• Also, both occur when an organism is broken into parts.
• Furthermore, both methods undergo mitotic cells divisions.

Difference Between Fragmentation and Regeneration

Definition

Fragmentation refers to a form of asexual reproduction wherein a parent organism breaks into fragments, each capable of growing independently into a new organism while regeneration refers to a process by which some organisms replace or restore lost or amputated body parts. This outlines the main difference between fragmentation and regeneration.

Types

The two main fragmentation methods are paratomy and achitomy while the three main methods of regeneration are epimorphosis, morphallaxis, and compensatory regeneration.

Broken Parts

Another difference between fragmentation and regeneration is that all broken parts of the organism develop into a new organism in fragmentation while all broken parts do not develop into a new organism in regeneration.

Specialized Cells

Also, no specialized cells are involved in fragmentation and it occurs through mitosis while specialized cells are involved in regeneration. This is another difference between fragmentation and regeneration. 

Occurrence

Furthermore, fragmentation occurs in organisms with a lower organization while regeneration occurs in organisms with a higher organization.

Examples

Fragmentation occurs in algae, flatworms, sponges, etc. while regeneration occurs in sea stars, mammalians, etc.

Conclusion

Fragmentation is an asexual reproduction method in multicellular organisms with a lower organization while regeneration is the method of regrowth of missing tissues in higher organisms. In fragmentation, each fragment develops into a new organism. Therefore, the main difference between fragmentation and regeneration is the way of development.

Reference:

1. Nagpal, Shilpi. “Fragmentation | Class 10, How Do Organism Reproduce.” ClassNotes, 11 Oct. 2016, Available Here
2. Gilbert SF. Developmental Biology. 6th edition. Sunderland (MA): Sinauer Associates; 2000. Regeneration. Available Here

Image Courtesy:

1. “Bryophyllum daigremontianum nahaufnahme1” By Photographer: CrazyD, 26 Octobre 2005 – Own work (CC BY-SA 3.0) via Commons Wikimedia  
2. “Dwarf Yellow-headed gecko edit” By Muhammad Mahdi Karimderivative work: Fletcher6 (talk) – Dwarf_Yellow-headed_gecko.jpg (GFDL 1.2) via Commons Wikimedia