What is the Difference Between Pleomorphic and Polymorphic

The main difference between pleomorphic and polymorphic is that pleomorphic is the occurrence of multiple structural forms during the life cycle whereas polymorphic is the coexistence of different forms independent of sex in the same locality.

Pleomorphic and polymorphic are two types of the existence of variant forms in organisms. Each form of variation occurs within the same species.    

Key Areas Covered

1. What is Pleomorphic
     – Definition, Features, Examples
2. What is Polymorphic
     – Definition, Features, Examples
3. Similarities Between Pleomorphic and Polymorphic
     – Outline of Common Features
4. Difference Between Pleomorphic and Polymorphic
     – Comparison of Key Differences

Key Terms

Pleomorphic, Polymorphic

What is Pleomorphic

Pleomorphic is the presence of different morphologies, biological functions, and reproductive modes in organisms in response to environmental conditions. It mainly occurs in lower organisms and microorganisms. Moreover, pleomorphism is the presence of morphological variation and functional methods in bacteria. Therefore, the characteristics developed by bacteria in response to environmental conditions are not heritable. The shedding of antigenic markers by bacteria in the presence of antibiotics is an example of pleomorphism in bacteria.

Figure 1: Coxiella burnetii Bacteria Displaying Pleomorphism

Furthermore, some bacteria drastically change their shape. For example, Helicobacter pylori occur in both helical form and coccoid form. Pleomorphic bacteria also occur in the blood of healthy humans. In addition, bacterial viruses change their appearance when they infect bacteria. Haloarchaeal viruses are an example of such viruses.

What is Polymorphic

Polymorphic is the coexistence of different forms, independent of sex, in the same locality. For example, light-morph jaguar and the dark-morph jaguar are the two different morphs of jaguars. They are alternative phenotypes in the same population. The main feature of morphs is that they inhabit the same habitat at the same time. They are also in the panmictic population with random mating. In simple words, polymorphism occurs when two or more possible traits are on a single gene.

Figure 2: Black-Morph of Jaguar

Moreover, polymorphism is common in nature. It is also related to genetic variation, adaptation, and biodiversity. Sexual dimorphism, which is the presence of two sexes in animals, the presence of hemoglobin variants in humans, and the presence of different blood types in humans are some examples of polymorphism.

Similarities Between Pleomorphic and Polymorphic

• Pleomorphic and polymorphic are two types of the existence of variant forms within the same species.
• Both bring morphological variation to the organisms.
• The characteristics developed by organisms are not heritable.

Difference Between Pleomorphic and Polymorphic

Definition

Pleomorphic refers to the occurrence of multiple structural forms during the life cycle of an organism while polymorphic refers to the coexistence, in the same locality, of two or more distinct forms independent of sex.

Examples

The occurrence of bacterial cells in different shapes is an example of pleomorphism while the presence of light-morph jaguars and dark-morph jaguars is an example of polymorphism.

Occurrence

Moreover, pleomorphism occurs in bacteria and viruses and microorganisms, while polymorphism occurs in higher organisms.

Genetic Variation

Pleomorphic structures are genetically similar while polymorphic structures are genetically different.

Organisms

Pleomorphic structures occur within the same organism while polymorphic structures occur in different organisms within the same species.

Importance

Furthermore, pleomorphism develops different morphologies during the life cycle of an individual organism while polymorphism brings variants of the same species to the ecological niche.

Conclusion

In brief, pleomorphic and polymorphic refer to the presence of different structural forms of organisms during their life cycle. Pleomorphic is the presence of different structural forms in the life cycle of organisms. Generally, it occurs in lower organisms such as bacteria and viruses. Furthermore, pleomorphic structures are genetically similar. In comparison, polymorphic is the presence of different forms of the same species in the same locality. It occurs in higher organisms. Polymorphic organisms are genetically different. Therefore, the main difference between pleomorphic and polymorphic is their occurrence and importance.

References:

1. “Pleomorphism vs Polymorphism – What’s the Difference?” WikiDiff, 6 Nov. 2022,.
2. “Pleomorphism.” Encyclopædia Britannica, Encyclopædia Britannica, Inc..

Image Courtesy:

1. “Coxiella burnetii 01” By NIAID – Own work (Public Domain) via Commons Wikimedia
2. “Black jaguar” By Ron Singer – Own Work (Public Domain) via Commons Wikimedia