Question

Which one of the following fungus shows heterothallism?
A. Erysiphe
B. Peziza
C. Rhizophora
D. Peronospora

Answer 1

Hint: Thallus or thalli is obtained by Greek word thallos which refers to small shoots, thalis are the undifferentiated tissue found in the dot region of some organisms such as algae, fungi and more. Plant species bearing thallus are called thallophytes. Some species have some similar structure as thallus, such structures are known as thalloid.

Complete answer:
Thallophytes can be divided into two forms based on their sexual morphology homothallic and heterothallic, and the phenomenon is known as homothallism and heterothallism respectively. Homothallism refers to the phenomenon where a thallophyta possesses both sexual morphology and reproduces sexually as they have both male and female reproductive structures on the same thallus. On the other hand heterothallism refers to the phenomenon where a thallophyta possess only one particular type of sexual morphology either male or female reproductive structure and they require the presence of both thallus to undergo reproduction, here also there is sexual reproduction. Erysiphe is a fungus which possesses both the reproductive structures of the same thallus and hence they are homothallic but a species known as Erisyphe Cichoracearum shows heterothallism in the lettuce strain. Peziza and Peronospora also show homothallism. Rhizophora belong to mycota and they exhibit heterothallism as they have only one particular type of reproductive structure on its thallus.

Hence the correct answer is OPTION(C)

Note: As in higher eukaryotes these organisms require compatible partners in order to complete the stages of reproduction. Each individual should contribute nuclei functional spores in order to form nuclei. Some of the organisms exhibiting heterothallism are Saccharomyces cerevisiae, Aspergillus flavus, Penicillium marneffei and Neurospora crassa.