Question

In Spirogyra, asexual reproduction, takes place by
A) Fragmentation
B) Spore formation
C) Budding
D) Binary fission

Answer 1

Hint: Spirogyra is a species that can reproduce both sexually as well as asexually. In them, sexual reproduction occurs by the process known as conjugation. In this type of reproduction, the conjugation tubes join together for the exchange of gametes and reproduction takes place.

Complete answer:
Spirogyra is a free-floating green alga that is present in freshwater bodies. The species is known to reproduce both sexually and asexually. In the asexual type of reproduction, the species reproduce by the process of fragmentation while in the sexual type of reproduction it reproduces by the process known as conjugation. In fragmentation type of asexual reproduction, the organism simply divides or breaks itself into different and numerous pieces and a new organism develops from these pieces. Spirogyra also divides itself into many fragments which result in the formation of many filaments. These filaments then grow to form the mature individual. In sexual reproduction of the Spirogyra, the filaments join with the help of conjugation tubes from which exchange of material takes place and the contents fuse together to form a zygote. The tube then gets surrounded by a thick layer and the vegetative filaments then die.

So, the correct answer is Option A, i.e., ‘fragmentation’.

Note: The Spirogyra species can reproduce by both sexual and asexual means of reproduction. It uses asexual means of reproduction when the conditions are not suitable for sexual means of reproduction. In fragmentation, the body of Spirogyra divides itself to form small fragments which then grow to form the mature filaments.