Question

Lichens are the associations of
(A) Bacteria and fungus
(B) Algae and bacteria
(C) Fungus and algae
(D) Fungus and virus

Answer 1

Hint: Symbiotic relationship is an association between two organisms which is mutually beneficial. One of the examples of such an association is Lichens.

Complete Answer:
- Lichens are organisms formed by the symbiotic association of algae and fungus. The association is mutually beneficial as one of the organisms carries out photosynthesis while the other one anchors itself on a solid substratum. Therefore, the need for food and shelter both are met.
- The association provides anchorage, minerals and water which is supplied by fungal partners. At the same time, the algal partner uses this to carry out the process of photosynthesis.
- Lichen can be formed by the association of cyanobacteria and fungus too.
- Fungi lack the capability of photosynthesis as they do not possess the pigment chlorophyll. This lack causes the inability of the fungus to harvest energy using sunlight; they generally depend on dead and decaying matter for their food.
- So, fungus associates itself with algae (photosynthetic) or cyanobacteria and provides them with a constant supply of nourishment in the form of minerals and water.

Thus, the correct answer is (C) fungus and algae.

Additional Information:
The fungal partner is termed as mycobiont and the algal partner is termed as phycobiont.

Note: Lichens are an association of two organisms in a single stable unit. The association is between a fungus and a photobiont. These photobiont can either be algae or cyanobacteria.