Asexual Reproduction Definition
“Asexual reproduction is the mode of reproduction that is involved in the production of offsprings by a single parent.”
What is Asexual Reproduction?
Asexual reproduction is a mode of reproduction in which a new offspring is produced by a single parent. The new individuals produced are genetically and physically identical to each other, i.e., they are the clones of their parent.
This is observed in both multicellular and unicellular organisms. This process does not involve any kind of gamete fusion and there won’t be any change in the number of chromosomes either. It will inherit the same genes as the parent, except for some cases where there is a chance of rare mutation to occur.
Also Read: Sexual Reproduction
Characteristics of Asexual Reproduction
1:- Single parent involved.
2:- No fertilization or gamete formation takes place.
3:- This process of reproduction occurs in a very short time.
4:- The organisms multiply and grow rapidly.
5:- The offspring is genetically similar.
Types of Asexual Reproduction
• Binary Fission
The term “fission” means “to divide”. During binary fission, the parent cell divides into two cells. The cell division patterns vary in different organisms, i.e., some are directional while others are non-directional. Amoeba and euglena exhibit binary fission.
It is one of the simplest and uncomplicated methods of asexual reproduction. The parent cell divides into two, each daughter cell carrying a nucleus of its own that is genetically identical to the parent. The cytoplasm also divides leading to two equal-sized daughter cells. The process repeats itself and the daughter cells grow and further divide.
Budding is the process of producing an individual through the buds that develop on the parent body. Hydra is an organism that reproduces by budding. The bud derives nutrition and shelter from the parent organism and detaches once it is fully grown.
Fragmentation is another mode of asexual reproduction exhibited by organisms such as spirogyra, planaria etc. The parent body divides into several fragments and each fragment develops into a new organism.
• Vegetative Propagation
This in plants occurs through their vegetative parts such as leaves, roots, stem, and buds. This is called vegetative propagation. For example, potato tubers, runners/stolon, onion bulbs, etc., all reproduce through vegetative propagation.
Spore formation is another means of asexual reproduction. During unfavourable conditions, the organism develops sac-like structures called sporangium that contain spores. When the conditions are favourable, the sporangium burst opens and spores are released that germinate to give rise to new organisms.
Advantages of Asexual Reproduction
• Mates not required.
• The process of reproduction is rapid.
• An enormous number of organisms can be produced in very less time.
• Positive genetic influences pass on to successive generations.
• It occurs in various environments.
Asexual Reproduction Examples
• Bacterium undergoes binary fission in which the cell divides into two along with the nucleus.
• Blackworms or mudworms reproduce through fragmentation.
• Hydras reproduce through budding.
• Organisms such as copperheads undergo parthenogenesis.
• Sugarcane can be grown through vegetative propagation.
Disadvantages of Asexual Reproduction
• Lack of diversity. Since the offsprings are genetically identical to the parent they are more susceptible to the same diseases and nutrient deficiencies as the parent. All the negative mutations persist for generations.
• Since only one organism is involved, the diversity among the organisms is limited.
• They are unable to adapt to the changing environment.
• A single change in the environment would eliminate the entire species.