Binary fission: types, process and examples of binary fission

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The division of cells and types of division is mostly a confusing topic to understand. By reviewing this content you may clearly understand about binary fission, its process, and the main difference between binary fission or mitosis. 

Binary fission is a type of asexual reproduction where parent cell cleave or split and developing two identical cells which are probable to increase in the size of their original cells. Asexual reproduction means, the reproduction which happens without the necessities of sex cells. As an alternate, somatic cell (non-sexual cell) goes through a sexual process and produces a clone (genetically identical individual) of parents. The progeny is clone because its genome will be similar to that of parents. Binary fission is the most common form of reproduction of duplication in Prokaryotes (such as archaea, cyanobacteria). Binary fission takes place in some single-cell named eukaryotes (such as amoeba, paramecium). In the process of binary fission DNA, replication and aeration occur simultaneously.

Types of binary fission

Binary fission is categorized into four types which are based on the division of cytoplasm.

1. Irregular binary fission

  • In this type of binary fission, the cytokinesis (cytoplasm) division can take place in any plane or flat but mainly occur in the perpendicular plane of division of karyokinesis (chromosome).
  • This type of binary fission takes place in amoeba.

2. Transverse binary fission

  • The cytokinesis (cytoplasm) takes place beside the transverse axis of the cell. 
  • This type of binary fission occurs in protozoan (paramecium).

3. Longitudinal binary fission

  • In this type, the division of cytokinesis occurs sling to its longitudinal axis of the cell.
  • This type of binary fission occurs in flagellates (Euglena).

4. Oblique binary fission

  • The division of cytokinesis (cytoplasm) occurs obliquely in both left or right.
  • This type of binary fission takes place in dinoflagellates (cerium).

Process of binary fission in Prokaryotes

The proceeds of binary fission is pretty much simple, and consisting of several steps to form Jew cells. During the division of cells, the DNA molecule of Prokaryotes is uncoiled before existene replicate to produce two chromosomes. Binary fission in Prokaryotes divided into four stages.

1. Replication of chromosome

Molecules of DNA that hold on or clasp the genetic code for cells of bacteria are usually tightly coiled. In this stage, this single chromosome is uncoiled and duplicated to form a new chromosome (doubling the genetics content).  

2. Cell growth

Cell growth is increasing in size for the preparation of binary fission. This increase in growth goes along with increases in the volume of cytoplasm with various organelle by increasing in numbers than the two strands begin to migrate or wander to opposite poles of cells. 

3. Segregation of chromosomes

In this phase, cells are elongated as a septum (dividing portion between tissue or capacity) form of the medium transversely. At this stage, the chromosome is separated completely. 

4. Cell splitting

Splitting of cells is the last phase in which a cell wall is formed. Eventually, cell splits along the center (at septum) divide the cell into two daughter cells, which contain nuclear material and cell organelle.

Example of Prokaryotes Binary Fission

1. Archaea

Archaea are classified as bacteria and they have a lack of nucleus and membrane-bound organelle. The reproduction process in archaea is asexual and it can reproduce by process of binary fission where parent cell split, it divides into two identical daughter cells.

Archaea also reproduce by budding and fragmentation (in which cells break off and form new cells). 

2. Cyanobacteria

Cyanobacteria also named as blue-green algae. Like other Prokaryotes cyanobacteria have a lack of nucleus and membrane-bound organelle (mitochondria, cytoplasm, chloroplast, and Endoplasmic reticulum). Cyanobacteria might be filamentous threadlike or unicellular and many cyanobacteria have scabbard to bind it to other cells.

  • They carry only one form of chlorophyll (i.e, chlorophyll-a), which is responsible for green pigment, while they also contain different yellowish carotenoids, blue pigment plycobitum, and a few are red pigment phycoerythrin. 
  • The amalgamation of phycobilin and chlorophyll responsible for producing blue-green color. They also reproduce asexually by process of binary fission or multiple fission in the form of colonies of unicellular or by process of fragmentation, spore formation in species of filamentous. Most cyanobacteria do not grow in the absence of light (they are obligate phototrophs) and some grow in dark (inadequate supply of glucose).

Binary fission in eukaryotes

In eukaryotes sexual reproduction is the most common process. Nevertheless, various of them can reproduce asexually. This fission can take a number of forms amid these are:

i. Budding: in which two daughter cells marked by unequal in size.

ii. Intracellular budding: in which daughter cell appear inside the organisms rather than splitting.

iii. Multiple fissions: Multiple fissions named as segmentation. in this the number of consecutive cycles of nucleus replication is followed by cytokinesis which may result in a multinucleated cell giving rise to numerous children at the same time.

Example of eukaryotes Binary Fission

1. Amoeba

Amoeba are tiny, non-shaped,  single-cell organisms and they live in moist conditions (such as freshwater, saltwater, and soil).

  •  Amoeba contains one or more than one nuclei depends on its species. Unlike higher forms of life, amoeba don’t require other individual genetic material to replicate it. Each nucleus contains genetic material to which the nucleus divides known as mitosis.  
  • The cytokinesis and outer membrane cleave in two. Each half contains a nucleus and new cells contain genetic material that is similar to the original known as binary fission.

2. Paramecium

Paramecium is a single cell protist and is found in aquatic habitats. Paramecium is covered with a hairy structure called cilia and they feed microorganisms (such as bacteria, algae, and yeast). The characteristic of parameciums is animal-like because it moves and looks for its own food.

  • Asexual reproduction occurs in paramecium in favourable conditions. Paramecium is divided into two daughter cell individuals and this process of division occurs at a high angle to the longitudinal axis of the body. 
  • The macronucleus is divided by amitosis while the micronucleus is divided by the process of mitosis. After the division of the cell they move with regards to the opposite pole and at this time of migration narrowing or tightening develops at the center part of the body to divide the cytoplasm into two parts.
  • Sexual reproduction in paramecium occurs in unfavorable conditions. In this type of reproduction two opposite types of paramecium come in contact with their ventral surface and this unit of paramecium is named as conjugants. 
  • The macronucleus is breakup and disappear while the micronucleus undergoes two consecutive division and four haploid nuclei fabricate or produce in each conjugants, then three nuclei disappear in this conjugant and remaining nuclei divide unequally to produce male pronucleus (smaller) and female pronucleus (larger) but both are genetically identical. 

Is binary fission the same as mitosis?

The division of cells and its process of division is somehow confusing to understand. Binary fission is not the same as mitosis. The similarities and dissimilarities between binary fission and mitosis are summed up,

Binary fission: In binary fission asexual reproduction is take place in which one organism divided to form two daughter cells.

Mitosis: Sexual reproduction takes place. The asexual reproduction is only the part of complex organisms.

1. Binary Fission: This occurs in prokaryotes, while some protist, eukaryotes (protozoan) divided by process of binary fission

Mitosis: This only occurs in eukaryotes.

2. Binary fission: The primary function of binary fission is reproduction.

Mitosis: Function of mitosis includes; growth, repair damages, and reproduction.

3. Binary Fission: Binary fission is a simple or rapid process.

Mitosis: Mitosis is a complex or complicated process and it may require a longer time as compared to binary fission.

4. Binary fission: Spindle fiber is not formed and DNA attached to the cell membrane for division.

Mitosis: In mitosis formation of spindle fiber occurs, and DNA attached to these fibers for division.

5. Binary fission: Binary fission used cytokinesis to divide the cytoplasm.

Mitosis: Mitosis also uses cytokinesis to divide cytoplasm.

6. Binary Fission: Replication of DNA and their separation occur at the same time.

Mitosis: Replication of DNA takes a longer time for division.

Before you leave!

In prokaryotic or eukaryotic cell division genomic DNA is replicated and each copy is allocated into daughter cells. The content of the cytoplasm divided evenly to form new cells. Although, there are many dissimilarities between the prokaryotic and eukaryotic cell division. The binary fission and mitosis are both formed asexually in which parent cells divide to form the genetically identical cells. Binary fission occurs in prokaryotes and some time in eukaryotes by simple and rapid process while the mitosis occurs only in eukaryotes and they take longer to reproduce.