Question

Indian species of spirogyra in which Prof. Iyengar discovered direct lateral conjugation is.
A. Spirogyra sahnii
B. Spirogyra indica
C. Spirogyra jogensis
D. Spirogyra karnalae

Answer 1

Hint: Spirogyra belongs to the division “algae “ of the kingdom “plantae". It is a multicellular unbranched filamentous algae. Conjugation: It is a unique type of sexual reproduction in which two individuals of the same species mutually exchange their micro nuclear material to form zygote.

Complete answer:
Mandayam Osuri Parthasarathy Iyengar was an Indian botanist and phycologist. He researched on the structure, reproduction, taxonomy, and cytology of algae.He primarily studied spirogyra.

> Conjugation in spirogyra:
• Gametes are formed in a single filament. The cells of two filaments lying side by side are joined by outgrowths called conjugation tubes. This allows the contents of one cell to completely pass into and fuse with the contents of the other cell. The resulting fused cell is called zygote.
• Conjugation occurs usually under some unfavourable living conditions such as starvation, sudden darkness, low temperatures etc.

Hence, the correct answer is option (C).

Additional information:
• Their predominant photosynthetic pigments are chlorophyll-a and chlorophyll-b.
• Reserved food is in the form of starch.
• The cell wall is composed of cellulose.
• Found mostly in freshwater and sometimes in marine and brackish water.
• It can reproduce both sexually and asexually.
• Asexual reproduction is done by means of fragmentation.
• Sexual reproduction is done by means of conjugation.

Note: Prof. Iyengar was a prominent Indian botanist and phycologist.
He is known as “ father of Indian phycology” and “ father of algology “ in India.
Sexual reproduction in spirogyra is by conjugation, direct lateral conjugation is discovered by Prof. Iyengar in Spirogyra jogensis.