i) Encysted Amoeba | a) Longitudinal binary fission |
ii) Paramecium | b) Multiple fission |
iii) Euglena | c) Transverse binary fission |
iv) Ceratium | d) Oblique binary fission |
Organisms | Mode of reproduction |
Encysted Amoeba | Multiple fission |
Paramecium | Transverse binary fission |
Euglena | Longitudinal binary fission |
Ceratium | Oblique binary fission |
Asexual reproduction in bacteria occurs by irregular or simple binary fission during favourable condition. Amoeba also shows binary fission but during unfavourable conditions, Amoeba withdraws its pseudopodia and forms a three-layered covering around it called the cyst wall. At this time, Amoeba is said to be encysted. This encysted Amoeba, on the arrival of favourable conditions, divides by multiple fission and forms and several minute amoebae called pseudopodiospores. Each pseudopodiospore can develop into mature Amoeba.
Depending upon the plane of division, binary fission can be of the following types:
Simple binary fission or irregular binary fission: It can occur through any plane, e.g., Amoeba.
Longitudinal binary fission: The plane of division passes along the longitudinal axis of the organism, e.g., Euglena
Transverse binary fission: The plane of division is through the transverse axis of the organism, e.g., Paramecium
Oblique binary fission: The plane of division is oblique, e.g., Ceratium