Key Difference – Binary Fission vs Conjugation
Microorganisms use sexual and asexual reproduction methods for multiplication. Binary fission is a common asexual reproduction method shown by single cell organisms including bacteria and amoeba. Matured parent cells split into two identical daughter cells in binary fission. Conjugation is a sexual reproduction method used by the bacteria to transfer genetic material to cells. Conjugation occurs via a conjugation tube formed between two cells or via direct contact of two cells. Thus, the key difference between binary fission and conjugation is that binary fission is a method of asexual reproduction which produces two genetically identical cells from a single mature cell while the conjugation is a sexual reproduction method used by bacteria for genetic material transfer between temporally connected two cells.
CONTENTS
1. Overview and Key Difference
2. What is Binary Fission
3. What is Conjugation
4. Side by Side Comparison – Binary Fission vs Conjugation
5. Summary
What is Binary Fission?
Binary fission is the most common asexual reproduction method exhibited by prokaryotic organisms and single cell eukaryotic organisms. Binary fission results in two genetically identical daughter cells from a single mature cell. Most bacteria depend on binary fission for propagation since it’s a simple and fast process. Binary fission starts at the origin of replication and duplicates the genome of the organism. Duplicated genomes segregate into two opposite ends of the cell. Plasma membrane grows inward and initiates the formation of the septum. Once the septum formation completes, the cell separates into two daughter cells. The size and the genetic composition of the daughter cells are identical. Basic steps of the binary fission are shown in figure 01.
Figure 01: Binary fission of a bacterial cell
What is Conjugation?
Bacteria conjugation is a mechanism that involves the direct transfer of genetic material between two bacteria. It occurs via cell to cell contact or by the formation of the conjugation bridge between temporally joined two cells. The two cells are named donor cell and recipient cell. One cell serves as the donor of the genetic material and the other cell is the recipient of the genetic material. Donor cell is composed of fertility factor (F factor) which needs to develop the sex pilus for contact and DNA transfer to the recipient cell. Recipient cell lacks the genetic material owned by the donor cell. Therefore, this genetic material transfer often offers a genetic advantage. Recipient cell acquires new characteristics which are encoded by the received DNA. Most of the antibiotic resistance genes are located in the plasmid DNA of bacteria. Therefore, some bacteria receive antibiotic resistivity through conjugation
Bacterial conjugation is initiated with the production of sex pilus by the donor cell. Sex pilus bridges the two cells and helps them to contact with each other. The plasmid of the donor cell comes near the sex pilus and nicks from one point to become single stranded. One strand of plasmid DNA transfers into the recipient cell via the conjugation tube formed. Both cells convert single-stranded plasmid DNA into double-stranded form by synthesizing the complementary strand.
Figure 20: Bacteria conjugation
What is the difference between Binary Fission and Conjugation?
Binary Fission vs Conjugstion |
|
| Binary fission is an asexual reproduction method which involves only one parent cell. | Conjugation is a sexual reproduction method which involves two parent cells. |
| Outcome | |
| This results in two genetically identical two daughter cells. | This results in genetically different offspring. |
| Speed of the Process | |
| Binary fission is a fast process. | Conjugation is a slow process. |
| F Factor | |
| F plasmids are not involved | F factor is involved in conjugation. |
| Mating | |
| Mating is not needed for binary fission. | Two parent cells should mate. |
| Environmental Influence | |
| Environmental conditions affect binary fission. | Environmental conditions do not affect conjugation. |
Summary – Binary Fission vs Conjugation
Binary fission and conjugation are two reproduction methods shown by bacteria. The main difference between binary fission and conjugation is that binary fission is an asexual reproduction method whereas conjugation is a sexual reproduction method. Binary fission is used by single cell organisms to produce two identical daughter cells. One mature cell is converted into genetically identical two copies in binary fission. Conjugation is used by bacteria to transfer genetic material between two parents and produce offsprings which are not genetically identical. Conjugation is important in transferring plasmids or transposons between two bacteria.
Reference:
1.Adelberg, Edward A., and James Pittard. “Chromosome Transfer in Bacterial Conjugation.” Bacteriological Reviews. U.S. National Library of Medicine, June 1965. Web. 03 Mar. 2017
2.”Binary fission.” Wikipedia. Wikimedia Foundation, 24 Feb. 2017. Web. 03 Mar. 2017
3.”Cornell University.” Binary Fission and other Forms of Reproduction in Bacteria | Department of Microbiology. N.p., n.d. Web. 03 Mar. 2017
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