Question

More common type of conjugation in Spirogyra is
A. Terminal
B. Indirect lateral
C. Direct lateral
D. Scalariform

Answer 1

Hint: Species of Spirogyra are able to reproduce both sexually and asexually. Vegetative or asexual reproduction is, however, the most common mode of reproduction. The fragmentation process, which is the most common mode of reproduction, takes place in asexual or vegetative reproduction. The conjugation process takes place in sexual reproduction.

Complete answer:
Sexual reproduction takes place in Spirogyra by conjugation, which consists of two types:
1. Scalariform Conjugation: In Spirogyra, it is the most common type of conjugation. The two filaments are male and female and act. Their cytoplasmic material is rounded up, resulting in gametes forming. The male gamete is transferred to the female filament through the conjugation tube and fuses with the female gamete to form the zygote. By forming a thick wall, the zygote becomes Zygospore. The male filament is empty, and the zygospore is borne by the female filament.
2. Lateral conjugation: Within the same filament, this kind of conjugation happens. In direct lateral conjugation, via a pore, the material of one cell acting as a male gamete moves into the neighboring cell acting as a female gamete and the zygospore is formed. The conjugation tube is formed between the adjacent cells in indirect lateral conjugation and the material of the male gamete is transferred to the female gamete that is adjacent to the male gamete.
Hence, the correct answer is option (D)-Scalariform.

Note: Approximately, 400 species of Spirogyra have been discovered in nature. Spirogyra is photosynthetic and contributes to the collection of carbon dioxide. In their environments, they raise the amount of oxygen and most aquatic species feed on them.