What is binary fission? | Process | Types

Binary fission also known as bipartition, is one of the types of asexual reproduction. Where two new completely identical living beings are formed. It is characterized by a very fast process in some organisms, so its growth can become exponential. It is a process used by bacteria and other organisms to carry out cell division which is completed in different steps.


What is binary fission?

The bipartition or binary fission is a mechanism of asexual reproduction of single-celled living beings, typical of prokaryotes such as bacteria and archaea. It consists of the duplication of the individual's cellular DNA, as a previous step to the division of the cytoplasm Thus, it produces two daughter cells with identical genetic material.

Read : DNA Replication

This is the most common form of reproduction in the bacterial world. In some species it can occur at an impressive rate (an Escherichia coli bacterium can divide once every 20 minutes), as long as the conditions of the surrounding environment are adequate.

In addition to rapid colonization of the environment, this reproductive rhythm has adaptive purposes: with that reproductive rhythm, the rate of mutations is usually high. This produces new bacterial strains better adapted to the environment (for example, more resistant to antibiotics). apart that this is the reason for the great evolutionary success of bacteria, present in absolutely the whole world.


What is binary fission? | Process | Types

Process of binary fission 

Step 1 : Replication of DNA
The fact that the binary fission is carried out in the prokaryotic cells makes it a simple and fast method due to its varied characteristics. As we know prokaryotic cell does not have a nucleus, therefore genetic information or DNA is located in the area called nucleoid. Which in turn contains a single chromosome that contains all the genetic information of the living being.
It is where the process of binary fission begins on this chromosome, which inside contains the element of origin of replication, where the DNA is duplicated.

Step 2 : Growth of Cell
Therefore, when the genetic material has already been duplicated and proceeds to separate, it creates two new origins. Which separate at each end of the chromosome until they come off. Thus, two new chromosomes with genetic load identity from the same stem cell and the growth of cell occur.

Read : Cell Structure & Functions

Step 3 : Isolation of DNA
Both DNA and plasmids have been duplicated. Individual copies of DNA adhere to different parts of the cell membrane. As the cell lengthens in preparation for division, DNA molecules are carried to different sides of the cell.

Step 4 : Cleavage
A cleavage groove appears in the cell membrane, as the cell wall and membrane begin to pinch and create two new cells. Finally, as seen in step 5, the cells separate completely from each other as a new bacterial cell wall forms.

The final step includes breaking down any additional proteins or other molecules that still connect the two cells. Each cell now has everything it needs to continue life's functions independently. This whole process in some species can take only 15 minutes. While others can reproduce at a slower rate.

Read : Mitosis

Types of binary Fission

Binary fission mainly consists of three types, which are characterized by the way of cell division. Each of these differences is essential to determine both the shape and resulting size of these organisms.

Simple binary fission
This occurs when the cell divides symmetrically, resulting in two new organisms of the same size. As in the case of amoebas.

Transverse binary fission
This binary fission results in a division of the cell in coincidence with the transverse axis of the organism. As occurs in the planar organism.

Longitudinal binary fission
The division of the stem cell is carried out in the direction of the longitudinal axis of the organism. As it is, in the case of Euglena.

Multiple binary fission
Organisms can be observed that the bipartition does not show a particular shape, since it is carried out in a multiple way. Furthermore, in this type of organism the nucleus is not divided into two parts. Causing the cytoplasm to divide as many times as the nucleus has been fractionated.

A diverse number of cells can be formed from a stem cell. Just as in the case of malaria, which can develop or populate a body, more than any other bacteria.


Examples of binary fission

There are plenty of examples of this type of reproduction. Most prokaryotic organisms and some eukaryotes use it. In fact, fighting bacterial infections is so arduous because its bipartition rate is high. Thus, they reproduce by binary fission:
  1. Bacteria of all kinds and genres, such as the Metada Escherichia coli, and archaea such as the extremophile Methanobacterium bryantii.
  2. Primitive eukaryotes such as Crypthecodinium cohnii or paramecium species.
  3. Some protozoa such as the amoeba (Amoebidae).
  4. Other types of asexual reproduction


Characteristics of the binary Fission

In asexual reproduction, two cells are formed with identical genetic information. Implying that every organism that reproduces through this method is equal to each other and will not have any modification. This creates great difficulty in adapting to new environments. Or, until you can stay in the same environment, if it undergoes any change. In the case of bacteria, they are exposed to be eliminated without major difficulty.

Although, the DNA mutation rate in bacteria has been found to be relatively high. Managing to develop resistance to antibiotics or subsist before the diversity of environmental conditions. The binary fission reproduction process is very efficient due to its simplicity. For this reason, under favorable environmental conditions, the growth of bacteria will be very fast.


DNA mutation in Binary Fission

In binary fission there is no combination of genes, however, this does not mean that there is no exchange of genetic material. For this, there are several methods that allow DNA mutation. Currently only 3 possible modes of bacteria exchange have been tested:

Conjunction : It is about uniting two bacteria, in this way the DNA of these two species can be recombined.

Absorption : It is a process where a cell integrates fragments of dead cells into its own DNA.

Transduction : It is carried out through a bacterial virus called bacteriophage, which carries out the process of transporting genes to a cell.

It should be noted that these three processes cannot be considered as sexual reproduction. Since they are not equivalent to this type of reproduction. Although, the result is that a bacterium can combine the genetic material of different parental cells. Basically, these processes aim to make it easier for bacteria, in addition to their mutation, to adapt to new environments. Guaranteeing its life time against antibiotics or any other threat, present in the environment that develops.


Non-sexual reproduction mechanisms :

Are those that involve a single individual. Therefore, they have little or no genetic variation. In addition to binary fission, these types of reproduction include:

Gemmation : The parent forms extensions or prominences of his body. Eventually, those extensions can separate from him and have a life of their own. In other cases, they continue together and start a colony. When it occurs at the cellular level, it is an asymmetric mitosis.

Sporulation. It consists of the production within the cell or in specialized organs (sporangia, for example), of cells wrapped in a super resistant covering, known as spores. They are able to survive long periods and very hostile conditions, and then produce a new individual when the environment is favorable.

Parthenogenesis. The new individual is created from the development of unfertilized female sex cells. Therefore, it is genetically equal to the parent. Some animals follow this process such as flatworms, rotifers, tardigrades, insects, amphibians, fish and crustaceans, and some reptiles also.


Frequently Asked Questions on Binary Fission

What is binary fragmentation in biology?
Answer: Binary fission is the separation of asexual reproductive body into two new bodies. In the process of binary fission an organism duplicates its genetic material, or deoxyribonucleic acid (DNA), and then splits into two new parts (cytokinesis), each new organism acquiring a copy of the DNA.


What kinds of  organisms do binary fission?
Answer: Organisms in the domain of archaea and bacteria carry binary fission. This form of asexual reproduction and cell division is also used by some organisms within eukaryotic organisms (eg, mitochondria).


What are the 4 stages of binary fission?
Answer: The steps involved in binary fission in Bacteria are:

Step 1- Replication of DNA.

Step 2 - Growth of cell.

Step 3- Isolation of DNA.

Stage 4- Cell division.


What is binary fragmentation with an example?
Answer: In biology, binary fission is a type of asexual reproduction where a parent cell divides, resulting in two identical cells, each with the ability to grow to the size of the parent cell. Binary fission is common among prokaryotes, e.g. Archaea, Eubacteria, Cyanobacteria, and some protozoans (such as amoebae).


What is binary fragmentation with diagram?
Answer: Binary fission is a type of asexual reproduction. It is a common type of reproduction found in amoeba-like bacteria and protists in which a fully developed parent cell divides into two, forming two new cells. After replicating its genetic material, the parent cell divides into two equally sized daughter cells.


Why is binary fission important?
Answer: Benefits of binary fission for bacteria

1- There is no need to waste time in intercourse because only one parent is needed for binary fission.

2- Two consecutive binary fission is shorter for eukaryotes.

3- daughter cells have all the same characteristics as their parents.


Is binary fission analogous?
Answer: Both binary fission and mitosis are forms of asexual reproduction in which a parent cell divides to form two identical daughter cells. Binary fission occurs mainly in prokaryotes (bacteria), whereas mitosis occurs only in eukaryotes (eg, plant and animal cells). The third main form of cell division is meiosis.


Why is binary fission faster than mitosis?
Answer: Binary fission does not involve in spindle formation (mitotic apparatus) and sister chromatids, which in its process is a faster means of cellular division than isomerism. Binary fission does not have four distinct cellular phases (from G1 to the last mitotic phase) that are seen in the mitosis.


What are the types of binary fission?
Answer: There are four types of binary fission including: irregular binary fission. Longitudinal binary fragmentation. Transverse binary fission.


What is an example of multiple fragmentation?
Answer: Multiple fission is one in which the nucleus divides it several times into the daughter of the nucleus and then the cytoplasm divides into as many cells as possible. Examples of multiple fission are Plasmodium, Chlamydomonas, algae that are reproduced by multiple fission.