Question

Mycorrhiza represents
(a) Antagonism
(b) Endemism
(c) Symbiosis
(d) Parasitism

Answer 1

Hint: Mycorrhiza is the relationship between green plants and fungus for various benefits they get from one another. The plant makes sugars by photosynthesis which they supply to the fungus as a food source. In return, the fungus supplies water and mineral nutrients taken from the soil to the plant for its metabolism.

Complete answer:
A Mycorrhiza represents a symbiosis between a fungus and plants where the fungus lives in the plant's rhizosphere and plays an important role in plant nutrition, soil biology, and soil chemistry. The plant gives the fungus colonies their shelter to live and supplies them organic food in the form of sugar therefore this can be considered as mutualism. In particular cases, Mycorrhiza may build a parasitic association as well with the host. This kind of relationship between the plants and fungus is seen in $92\%$ of the plant families studied till now.

Additional Information: The action of any organism to suppress or interfere with the normal growth and activity of a plant pathogen is said to be antagonism. These have several uses in agriculture for the function of pest control and are known as biological control agents. They attack the harmful pests or weeds or any other organism in its vicinity by secreting potent enzymes that destroy other cells by digesting its cell walls. An example of such an antagonist is Aspergillus and it affects Penicillium and Cladosporium.
Endemism is known as the state of a species being native to a single defined geographic location and is not found anywhere else. An example of such an ecological state is the orange-breasted sunbird being found exclusively in the fynbos vegetation of southwestern South Africa.
Parasitism is an ecological interaction between two organisms in which the parasitic one gets benefits from the host by harming them in some way. An example of such a relationship is Petromyzon and shark where Petromyzon gets food from the shark by causing injury on the shark's body or even killing it.
Therefore, the correct answer is “(c) Symbiosis”.

Note: Symbiosis is also known as mutualism because of the fact that both the organism gets mutual benefits. Pollination of flower plants by animals, corals with zooxanthellae are some other examples of such ecological interaction. Symbiosis cab sometimes drifts from mutualism and may become parasitic or commensal.