Question

Lichens are a well-known combination of an alga and a fungus where the fungus has
A. An epiphytic relationship with the alga
B. A parasitic relationship with the alga
C. A symbiotic relationship with the alga
D. A saprophytic relationship with the alga

Answer 1

Hint: Lichens are an association between the Algae and the Fungi. Algae is a photosynthetic organism whereas the fungus is saprophytic. Moreover, both the organisms are somehow benefitted from the presence of one another.

Complete step by step answer: Lichens are a symbiotic relationship between Algae and Fungi. The term Lichen was given by Theophrastus which means independent plants. It is also known as a mutual relationship. This is because both the organisms are benefited from this association somehow.
The fungal partner is known as the mycobiont. It is the dominant partner and it makes up about ninety-five percent of the lichens. On the other hand, the algal partner is known as the phycobiont. Phycobiont is the recessive partner and it makes up only five percent of the lichen. In lichens, the fungus depends on the algae for food, as fungi cannot perform photosynthesis. In return, they provide shelter to the algae. Thus, based on the above information we can conclude that Lichens are a well-known combination of an alga and a fungus where the fungus has a symbiotic relationship with the alga.
Hence, the correct answer is option (C).

Note: A special term is given to the relationship of the fungi and algae in lichens. It is known as Helotism. Helotism is a type of parasitism. Helotism has controlled parasitism actually. In helotism, the parasite keeps its host alive and uses it. But the parasite does not allow it to die also. So, one partner is benefitted and the other partner is only partly benefitted and it is partly at loss too.