Question

Which of the following processes cannot introduce variations in the population?

Answer 1

Variations are differences that occur between members of the same species. Presence of variations in organisms prevents any two individuals of the same species from being identical to each other.

Genetic variations can be introduced in a population by

a. gene mutations: changes in the nucleotide sequences of DNA (genes).

b. genetic recombination: exchange of genetic material between the chromosomes and is observed during the formation of gametes by meiosis. Fusion of such gametes during sexual reproduction brings about variations in the offspring of the same species.

On the other hand, asexual reproduction is the process in which offspring are produced from a single parent. It doesn't involve meiosis and fusion of gametes. It is common in lower organisms. It can occur either by direct mitotic divisions of unicellular organisms, fragmentation of parent body, production of asexual reproductive structures such as spores (also developed due to mitotic divisions) which can grow into an entire organism, etc. It is also observed in higher organisms such as angiosperms by the method of vegetative propagation through vegetative plant parts such as roots, stems, leaves, etc.

As the offspring is produced from a single organism (uniparental) in the asexual reproduction, the offspring are identical copies or clones of its parent as well as its siblings.

Thus, no variations can be caused due to asexual reproduction.