Ans: The process of producing offspring that are biologically or genetically similar to the parent organism is called ‘reproduction’.
What is Reproduction?
The meaning of reproduction is to reproduce. The continuity of species, generation after generation is ensured by reproduction. Reproduction is the main feature of living things.
Types of Reproduction
There are basically two types of reproduction:
a. Asexual Reproduction
b. Sexual Reproduction
a. Asexual Reproduction:
It is the type of reproduction in which only a single organism gives birth to a new individual on its own.
The offsprings produced in asexual reproduction are genetically identical to the parent. The organisms are less diverse in nature because there is no fusion of gametes involved. Unicellular organisms use this type of reproduction.
Rapid population growth is involved and no mating is required for the process. But, because of the organisms being less diverse, they are much vulnerable to diseases and susceptible to nutrition deficiencies.
Asexual reproduction is also of some categories:
1. Binary Fission: The cell splits into two each cell carrying a copy of the DNA from the parent cell. For e.g., amoeba.
2. Budding: A small bud-like outgrowth gives rise to a new individual. The outgrowth remains attached to the organism until it is fully grown. It detaches itself as lives as an individual organism. For e.g., hydra
3. Fragmentation: The parent organism splits into several parts and each part grows into a new individual. For e.g., Planaria
4. Sporogenesis: Type of reproduction, a new organism grows from the spores. These can be created without fertilization and can spread through wind and animals.
b. Sexual Reproduction:
Sexual reproduction involves the production of an offspring by the fusion of male and female gametes. The organisms are more diverse in nature because there is fusion of gametes involved. Complex organisms use this type of reproduction.
Male and female gametes are formed to produce an offspring. These gametes are either formed by the same individual or by different individuals of the opposite sex.
This is usually a slow and complex process compared to asexual reproduction. Because of that the organisms produced are genetically diverse. They can evolve along with the changing climatic conditions. Humans along with many other multicellular complex organisms exhibit a sexual mode of reproduction.
Reproduction in Plants
Plants do reproduction by sexual and asexual means. The main mode of plant reproduction is vegetative reproduction. Roots (such as a corm), stem tuber, rhizomes and stolon undergo vegetative propagation and take part in reproduction.
Plants take part in sexual reproduction through pollination in which the pollen grains from the anther of a male flower transfer to the stigma of the female flower. Some plants produce seeds without fertilization and the process is called apomixis. The ovule or the ovary gives rise to new seeds in apomixis.
Reproduction in Animals
Animals also reproduce sexually as well as asexually. Here in this case too sexual reproduction involves the fusion of male and female gametes. This is known as fertilization. Fertilization can be of external or internal type. External fertilization is when the male sperm fertilizes the female egg outside the female’s body and in internal fertilization, the fusion of male and female gametes takes place inside the body of the female.
Asexual reproduction involves reproduction processes such as binary fission, budding, fragmentation, etc. The organisms have no reproductive systems and therefore no formation of male and female gametes takes place.