Lichens
Examine lichens as a symbiotic association between algae (phycobiont) and fungi (mycobiont), and their ecological significance.
What is Lichens?
A composite organism that arises from algae or cyanobacteria living among filaments of multiple fungi species in a symbiotic relationship.
Key points
- Define lichen and describe its symbiotic nature.
- Identify the roles of the mycobiont and phycobiont.
- Explain the ecological significance of lichens, including their role as bioindicators and in succession.
- Recognize different lichen growth forms.
Common exam trap
Confusing lichens with simple plants or mosses.
Definitions
- Term
Lichen
- Meaning
A composite organism that arises from algae or cyanobacteria living among filaments of multiple fungi species in a symbiotic relationship.
- Term
Mycobiont
- Meaning
The fungal component of a lichen, providing structure and protection.
- Term
Phycobiont
- Meaning
The algal or cyanobacterial component of a lichen, responsible for photosynthesis.
- Term
Mutualism
- Meaning
A symbiotic relationship in which both species benefit.
- Term
Bioindicator
- Meaning
An organism that indicates the health of an ecosystem, often by its presence, absence, or abundance, or by its physiological response to environmental changes.
Learning objectives
Define lichen and describe its symbiotic nature.
Identify the roles of the mycobiont and phycobiont.
Explain the ecological significance of lichens, including their role as bioindicators and in succession.
Recognize different lichen growth forms.
Prerequisites
Basic understanding of symbiotic relationships (mutualism).
Knowledge of photosynthesis.
Familiarity with basic fungal and algal structures.
Common mistakes
Confusing lichens with simple plants or mosses.
Underestimating their ecological importance.
Not recognizing the dual nature of the organism (fungus + alga/cyanobacterium).
Keywords
Lichen
Symbiosis
Mutualism
Fungi
Algae
Cyanobacteria
Mycobiont
Phycobiont
Bioindicator
Ecological Succession
Crustose
Foliose
Fruticose
Practice preview
Which of the following statements about lichens is INCORRECT?…
medium
Lichens are a classic example of:…
easy
Which of the following is a characteristic role of the fungal partner (mycobiont) in a lichen?…
easy