S. No. |
Asexual reproduction |
Sexual reproduction |
(i) |
Asexual reproduction does not involve formation or fusion of gametes. |
Sexual reproduction involves formation and fusion of gametes. |
(ii) |
The offsprings formed by asexual reproduction are genetically identical to the parent and are referred to as clones. |
The offsprings are not identical to the parents or to each other hence, it leads to variation in a population. |
(iii) |
It is a simple and fast process. |
It is an elaborate, complex and slow process |
(iv) |
It involves only mitosis. |
It involves meiosis |
(v) |
It is always uniparental (single parent) |
It is usually biparental (two parents). |
(vi) |
It does not play important role in evolution process. |
It plays a vital role in evolution process. |
(vii) |
It is common among single-celled organisms, and in plants and animals with relatively simple organisation. |
It is common in higher animals with complex organisation. |
Fission: The splitting of parental cell into two or more daughter cells.
(a) Binary fission: The splitting of a parental cell into two equal daughter cells, each of which rapidly grows into an adult is called binary fission. It occurs in single-celled animals like bacteria and protozoans (e.g., Amoeba, Paramecium). It can be simple or irregular, longitudinal, oblique or transverse, depending on the plane of division.
Binary fission in Amoeba
(b) Multiple fission: The splitting of a parent cell into numerous daughter cells, each of which grow into an adult is called multiple fission,
e.g., Plasmodium.
Multiple fission in Plasmodium
Sporulation: During unfavourable conditions, organisms like Amoeba cover themselves with a three-layered hard covering or cyst. This is called encystation. On return of favourable conditions, it divides by multiple fission within the cyst and produces many Amoebae. The cyst bursts and spores are liberated to develop into adults. This is called sporulation.