Q.What is a lichen? Explain the respective roles of the phycobiont and the mycobiont in this symbiotic association.

[!TLDR]

A lichen is a symbiosis between an algal phycobiont, which photosynthesises, and a fungal mycobiont, which absorbs water/minerals and shelters the alga. …

A lichen is not a single organism but a close, stable symbiotic association between an alga and a fungus. The algal partner is called the phycobiont, and the fungal partner is called the mycobiont.

The phycobiont, being photosynthetic, manufactures food using sunlight and supplies it to the fungal partner, which cannot photosynthesise on its own. The mycobiont, in turn, absorbs water and dissolved minerals from the substrate (rock, bark or soil) and provides a protective, moisture-retaining physical shelter within which the algal cells can live safely. Because each partner supplies something essential that the other cannot provide for itself, the two components are so tightly interdependent that the lichen behaves, structurally and functionally, almost as a single organism …

Define the lichen partnership and explain the specific, complementary role each named …

Describing the relationship as one-sided (only the fungus benefiting) instead of correctly presenting it as a mutually beneficial assoc …