Question

Heterothallism refers to

• A. Fusion is not accompanied with zygote formation
• B. Fusion between morphologically similar strain
• C. Fusion between the strains that are structurally similar but physiologically different
• D. All of the above

Answer 1

Answer: (C)

Fusion between the strains that are structurally similar but physiologically different

The participation of two or more type of strains or mating types is considered as heterothallism. An example of this phenomenon is shown by Rhizopus sp. There are two different mating types as + and -. These strains are structurally similar and physiologically different. The mycelium of these mating types interact and thus, zygospore is formed which help in the development of heterothallic mycelium. Thus the correct answer is option C.