Binary Fission

Our world is home to many billions of single-celled organisms. These organisms have appeared long before the rise of man and might be around long after we are gone. These organisms are very resilient to most environmental factors and are extremely adaptive.

As we all are aware of reproduction, its process, and significances. Binary fission is also a similar process of cell division, which is carried out in all prokaryotes.  Here, let us discover more about binary fission, its process and how do the prokaryotes ensure the continuity of their species.

What is Binary Fission?

Binary fission is a type of asexual reproduction and the most common form of reproduction in all prokaryotes and some single-celled eukaryotes. In this method of asexual reproduction, there is a separation of a parent body into two new bodies by duplicating its genetic material and divides into two parts where every new organism receives one copy of DNA.

It is a primary method of reproduction in prokaryotic organisms. Binary Fission occurs without any spindle apparatus formation in the cell. Here, the single DNA molecule replicates first and then attaches each copy to the cell membrane’s different part. When the cell started to pulls apart, the original and replicated chromosomes get separated. This mode of asexual reproduction has a consequence that all the cells are identical genetically which means that they follow the same genetic identities.

Binary fission is the primary method of reproduction of prokaryotic organisms. Organisms like the amoeba, bacteria, euglena, etc., undergo binary fission.

Binary Fission

Binary Fission in Bacteria

The process of Binary fission is usually rapid and its speed varies from species to species. These cells generally divide after every 20 minutes at the temperature of 37 degrees Celcius. The newly developed cells will undergo this process on their own and the time required by this method is equal to the time that the bacterial culture needs to double in the number of cells it has. This time period can be considered as the doubling time.

There are some species having faster doubling times and one of them are strains of Mycobacterium tuberculosis which have doubling time of 100 hours. An increase in bacterial growth is restricted by various factors that include nutrient availability and space available, so this process of binary fission takes place at much lower rates once they get into the stationary growth phase.

The steps involved in the bacterial binary fission are:

Step 1-  Replication of DNA

The bacterium cell uncoils itself to copy its DNA so that the new cells will have DNA and then duplicates. This DNA includes all the information of the bacterium that needs an organism to survive. Therefore, it is important to copy it.

Step 2-  Growth of a Cell

After copying the DNA structure, the bacterium starts to grow larger and increases in size, which will allow the separation between the two duplicated chromosomes, attached to the plasma membrane and are present inside the cell.

Step 3-Segregation of a DNA

The distance created between two Chromosomes finally forms the division in the middle of the bacterium. And, eventually, this division completely divides the bacterium into two halves. This whole process is known as cytokinesis.

Step 4- Splitting of Cells

The two divided cells will now be called a daughter cell. Binary fission leads to develop two identical daughter cells. The new daughter cells have tightly coiled DNA rods, plastids, and the ribosomes.

Binary Fission in Amoeba

Amoeba is a shapeless and small unicellular organism that has a Cell membrane which includes cell organelles and cytoplasm. Amoeba also reproduces with the most common asexual process known as binary fission.

After replicating its genetic material through mitotic division, the cell divides into two equal sized daughter cells. In this method, two similar individuals are produced from a single parent cell. As mature amoeba is large in size, its nucleus extends and gradually divides into two. The division of cytoplasm follows the division of the nucleus. So, two amoebae are produced from a single parent and parent’s identity is lost.

Important Question on Binary fission:

How does Amoeba reproduce?

Amoeba is unicellular organisms, which reproduce asexually through the method of binary fission. In this process, an individual divides itself into two equal halves producing their daughter cells identical to each other

List out the similarities and differences between Binary fission and mitosis?

Similarities:

  • During the process of Binary fission and mitosis, there is a copying of chromosomes before a cell divides and separates to form two new daughter cells.

Differences:

  • Mitosis is a process of cell division, observed in all eukaryotes-  Organisms with a true nucleus.
  • Binary fission is a process of asexual reproduction, carried out by all prokaryotes- Organisms without the nucleus.

How many types of Binary fission are there?

Listed below are different types of Binary fission:

  1. Simple Binary fission
  2. Longitudinal Binary fission
  3. ObliqueBinary fission
  4. Transverse Binary fission

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Practise This Question

Which of the following statements defines the density of population?