Lichens are not single organisms but composite life forms made up of a fungus and an alga, or sometimes a fungus and a cyanobacterium, living in close symbiosis. The fungus provides physical structure and water retention, while the alga or cyanobacterium produces sugars through photosynthesis. Together, they thrive in habitats too harsh for either partner alone.
What is the main purpose of the text?
- A
To trace the historical study of fungi.
- Bcheck_circle
To explain the symbiotic structure of lichens and the roles of each partner.
- C
To compare lichens with mosses.
- D
To argue that lichens should be reclassified as a single species.
Explanation
The text describes the partnership and the roles of each member. B captures the explanatory purpose.