What is the Difference Between Binary Fission and Conjugation

The main difference between binary fission and conjugation is that binary fission is a method of asexual reproduction responsible for duplication of an organism whereas conjugation is a method of horizontal gene transfer in prokaryotes. Furthermore, binary fission produces two daughter organisms that are genetically identical while conjugation occurs through the cell-to-cell contract between two organisms. In addition to these, binary fission occurs in both prokaryotes and eukaryotes while conjugation occurs in bacteria. 

Binary fission and conjugation are two methods of reproduction in lower organisms. Generally, both methods produce a particular type of offspring. 

Key Areas Covered 

1. What is Binary Fission
     – Definition, Process, Importance
2. What is Conjugation
     – Definition, Process, Importance
3. What are the Similarities Between Binary Fission and Conjugation
     – Outline of Common Features
4. What is the Difference Between Binary Fission and Conjugation
     – Comparison of Key Differences

Key Terms 

Asexual Reproduction, Binary Fission, Conjugation, Gene Transfer, Pilus

What is Binary Fission 

Binary fission is a type of asexual reproduction which occurs in prokaryotes, organelles, as well as unicellular eukaryotes. Prokaryotes such as bacteria an archaea undergo binary fission. In bacteria, a single chromosome undergoes replication followed by the attachment of the two DNA molecules into separate locations in the cytoplasm. In the meanwhile, the parent cell increases its size. Finally, the parent cell splits into two through the formation of the ‘Z-ring’. Furthermore, the two resultant cells have identical genetic material.

Figure 1: Binary Fission

Binary fission is the method of reproduction in organelles such as mitochondria and chloroplasts. They also use bacteria-like fission as these organelles are derived from the endosymbiosis of bacteria. In contrast, binary fission in unicellular eukaryotes occurs in four methods. They are: 

1. Irregular fission – Cytokinesis can take place along any plane, which is perpendicular to the plane of karyokinesis. e.g. amoeba  
2. Longitudinal fission – Cytokinesis takes place along the longitudinal axis. e.g.Euglena 
3. Transverse fission – Cytokinesis takes place along the transverse axis. e.g.Paramecium
4. Oblique fission – Cytokinesis is oblique. e.g.Ceratium 

What is Conjugation 

Conjugation is one of the methods of horizontal gene transfer, mainly in bacteria. However, transduction and transformation are the other methods of horizontal gene transfer in bacteria. Generally, conjugation occurs through the direct contact of two bacterial cells through a pilus. Here, genes for the antibiotic resistance, xenobiotic tolerance, etc. are transferred from one to the second bacterium. Therefore, this transformation of genes is beneficial to the recipient bacterium.

Figure 2: Bacterial Conjugation

However, conjugation does not form a generation of new organisms. It also occurs through the exchange of genetic material but, not the exchange of gametes. Therefore, conjugation is not considered as a method of sexual reproduction. Moreover, the transferring of genetic materials can be either plasmids or transposons. 

Similarities Between Binary Fission and Conjugation  

• Binary fission and conjugation are two methods of reproduction responsible for the production of an offspring. 
• They take part in the transfer of genetic information. 

Difference Between Binary Fission and Conjugation 

Definition 

Binary fission refers to the process through which asexual reproduction occurs in organisms while conjugation refers to the method of transferring genetic material between organisms. 

Occurrence 

Binary fission occurs in both prokaryotes and eukaryotes while conjugation occurs in bacteria. 

Process 

Moreover, binary fission occurs through the split of parent organisms into two and the regeneration of two pieces while conjugation occurs through the cell-to-cell contact. 

Number of Parents 

Whereas binary fission requires only a single parent organism, conjugation requires two parent organisms. 

Offspring 

Binary fission produces two daughter cells that are genetically identical, while conjugation produces two daughter organisms that are genetically diverse. 

Environmental Conditions 

Furthermore, binary fission occurs in favorable environments, while conjugation occurs in unfavorable conditions. 

Continuity 

Binary fission is a continuous process over many generations, while conjugation occurs after several generations. 

Speed 

While binary fission is a quick process, conjugation takes time. 

F-Factor 

No F-factor is required for binary fission while conjugation requires F-factor. 

Conclusion 

Binary fission is a type of asexual reproduction used by both eukaryotes and prokaryotes. It is also responsible for the production of two genetically identical daughter organisms by splitting the parent organism into two. In contrast, conjugation is a type of horizontal gene transfer in prokaryotes. Generally, it occurs through the formation of cell-to-cell contact through a pilus. However, it is not a type of sexual reproduction. Therefore, the main difference between binary fission and conjugation is the method of transferring genetic material. 

References:

1. “Bacterial Binary Fission.” Khan Academy, Khan Academy, Available Here.
2. Karki, Gaurab. “Bacterial Conjugation: Steps and Mechanism of Transfer of Plasmid from Donor to Recipient Cell.” Online Biology Notes, 18 Dec. 2018, Available Here.

Image Courtesy:

1. “Binary Fission 2” By Ecoddington14 (CC BY-SA 3.0) via Commons Wikimedia   
2. “Conjugation” By Adenosine – Own work (CC BY-SA 3.0) via Commons Wikimedia