Indicate the main distinguishing features of lichens.

A lichen is an organism, the result of a symbiosis of two components, namely algae and a fungus, the cohabitation of which creates this complex organism. This symbiosis is already a hallmark of lichens.

A distinctive feature is also the formation of lichen substances – secondary metabolic products that are not found in other groups of organisms.

A lichen is characterized by a special type of metabolism, which is significantly different from the metabolism of individual algae and fungi.

Lichens also form special forms of structure, which have developed through the historical process of symbiosis of fungus and algae.