Fission Fission means ‘to break’. Thus in this method an organism can divide into two or more organisms. So it can be of two types:
1. Binary fission
2. Multiple fission
Binary Fission
The term ‘binary fission’ consists of two words ‘binary’ and ‘fission’. The word ‘binary’ means ‘two’ and the term ‘fission’ means ‘to break’. It may be defined as the division of an organism into two offsprings or daughter organisms.
This method of reproduction is found in protozoans like amoeba, paramecium and bacteria. In this method under favourable conditions the parent organisms grows to its full extent and then divides into two parts. Each part of the parent then separates and grows into a new organism. This process is repeated further by the new organisms to produce a large number of organisms.
Multiple Fission
The term ‘multiple fission’ consists of two words ‘multi’ and ‘fission’. The word ‘multi’ means ‘many’ and the term ‘fission’ means ‘to break’. It may be defined as the division of a parent into many small offsprings or daughter organisms, at the same time.
This method of reproduction is also shown by protozoans such as amoeba, paramecium and plasmodium.
Multiple Fission in Amoeba
In this method, sometime under unfavourable or drastic conditions a very tough layer which is called as cyst is formed around the parent amoeba. Inside the cyst, the nucleus of the parent divides many times to form many nuclei. Later on, the cytoplasm of the cyst also divides
and each part of the cytoplasm encloses one nucleus. In this way many small amoebae are produced inside the cyst. On the return of favourable conditions, the cyst breaks and all the amoebae are released. These amoebae then grow into adults.
Multiple fission in Plasmodium
Plasmodium is the malarial parasite which produces malaria disease in human beings. The method of multiple fission in plasmodium is same as that of the amoeba.
Test Your Understanding and Answer These Questions:
- What is binary fission? Give example of binary fission.
- Explain binary fission in amoeba.
- What is multiple fission? Give example of multiple fission.
- Explain multiple fission in amoeba.
- Explain multiple fission in plasmodium.