Question

Name the algal and fungal component of Lichens.

Answer 1

Hint: A lichen is a fungus that forms a symbiotic relationship with an algal species. The algal component helps by providing food and energy because a lichen is not capable of undergoing photosynthesis. On the other hand, the filaments of the fungal component protect the algal component from various environmental stresses.

Complete answer:
Lichens are made of two components – a fungal component and an algal component. The fungal component is known as mycobiont, and the algal component is known as phycobiont. Due to this, it is also referred to as a composite organism.

Lichens cannot perform photosynthesis because they lack chlorophyll, the key component needed for the process of obtaining energy. So, they attain their energy in the form of carbohydrates from their algal component. i.e. phycobiont.

Phycobiont contain chlorophyll and due to this, they are able to synthesise sugars by photosynthesis. The sugars that are produced are eventually utilised by both the components of the lichen.

At the same time, the mycobiont protects the phycobiont from the environmental stresses with the help of fungal filaments. The fungus also protects the algae by retaining water.

The relationship between the mycobiont and phycobiont is symbiotic. However, in this case, both the components benefit in some way or the other.

Note: The algal component produces sugar alcohols after photosynthesis. These include – sorbitol, ribitol, and erythritol. These get used by the fungus.
Even though both the components of a lichen get benefitted in this relation, the fungal component ends up gaining more than the algal component. A major portion of the sugars produced by photosynthesis is used by the mycobiont and the phycobiont gets a disproportionately lesser amount.