Reproduction in organism – Asexual reproduction
It is a biological process of continuity of a race in which the grown up individual give rise to off springs similar to them.
Importance of reproduction :
I) Creates variation among population .
II) Maintain life on the earth.
III) Enables continuity of the species.
There are two basic type of reproduction found in both plants & animal-
I) Asexual reproduction(Mitotic div)
II) Sexual reproduction(Meiosis div)
It may be defined as the method of reproduction in which production or union of gamete are not involved .It occurs by the process of mitotic division of the nucleus or cytoplasm of the body, so it is known as – somatogenic reproduction .In plants this type of reproduction is known as vegetative reproduction.
The off spring produce by the asexual reproduction are the exact copies of their parents as identically similar both morphologically and genetically. So, the offspring are generally termed as clones.
The morphologically or genetically identical offspring produced by asexual reproduction are commonly known as clones.
|Honey bee||15-20 days|
|Rice plant||4 months|
|Fruit fly||1 day|
Mode of asexual reproduction :-
Fission can be occurred either by the following types:-
1) Binary fission
2) Multiple fission
1) Binary fission:-
It is the type of fission in which parent body divides into two small nearly equal size daughter individual.
Eg: Binary fission of amoeba
Binary fission is again divided into following types –
I) Irregular or simple binary fission.
II) Longitudinal binary fission.
III) Transverse binary fission.
I) Irregular or simple binary fission:
When division occurs in only one plane is called simple or irregular binary fission .
II) Longitudinal binary fission:
When the fission occur along the longitudinal axis of the animal or individuals,is known as longitudinal binary fission.
III) Transverse binary fission:
When the division occur at right angle to the long axis of animal ,is known as transverse binary fission.
2) Multiple fission:
It is the type of fission in which parent body divides into many small daughter individuals . eg: Plasmotium.
In this type the nucleus divides several times without the division of cytoplasm.Each daughter nucleus in later stage is surrounded by dividing cytoplasm and thus form many daughter cells.
Formation of daughter individual as an out growth of the parent body is called budding.This out growth is separated from the parent body and thus grow into an independent, self supporting individual ,identical to the parent.
eg: Hydra, Yeast, Spongilla, Obelia etc.
It is a small unicellular body called spare.The spore when mature separated from the parent body and grow into as a new organism.It is commonly sun in monera, protista, fungi and algae. Spore form can be of following main types-
I) Zoo spares
These are unicellular flagellated bodies.They are generally motile.
Coridia are mainly found in some fungi. In vegetative part of the penicillium some spore has develop.These spore which takes part in asexual reproduction.These generally non-motile.
In porifera, sporoges has developed some cellular spore which is generally termed as gemmule. They are non-motile.
It is another type of asexual reproduction in which the missing part of the organism is repaired by the proliterotion (cell division) of cell.
eg: Hydrus, sponge, planoria etc.
It is the process of breaking of the parent body into two more parts each of which grows form an independent individual. It is also a form of regeneration.
eg: Marchtia, Spiroggra (algae) (Bryophytes)
F) Vegetative propagation:
It is the process of formation of a new atoms from vegetative part of plants .The term vegetative propagation is used to denote asexual reproduction in plants.Vegetative propagation can be divided into two parts-
1) Natural vegetative propagation
2) Artificial vegetative propagation