Lichens Overview

These flashcards cover key concepts and details about lichens, including their structure, types, ecological roles, and reproductive methods.

What is the significance of lichen species like Trebouxia and Nostoc?

Trebouxia is a unicellular green algae commonly found in fruiticose lichens, while Nostoc is a cyanobacteria that contributes to the gelatinous structure of crustose lichens.

Describe the association between Mycobiont and Photobiont in lichens.

Mycobionts are fungi that provide water and minerals, while Photobionts are algae or cyanobacteria that perform photosynthesis within the thallus of the lichen.

What are the primary colonizers in an ecosystem during primary succession?

Lichens and moss are often the first organisms to colonize bare rock in primary succession.

What types of organisms typically form lichens?

Lichens consist of a fungus (Mycobiont) and a photobiont, which can be either algae (eukaryotic green or prokaryotic cyanobacteria).

What are the three basic kinds of lichen thalli?

Crustose, foliose, and fruticose are the three basic forms of lichen thalli.

What does the term 'thallus' refer to in lichens?

The thallus refers to the composite body of a lichen, composed of fungal hyphae, algal cells, and structured layers such as cortex and medulla.

What reproductive structures are commonly formed by Ascomycota lichens?

Cup-shaped apothecia are commonly formed as reproductive structures by Ascomycota lichens.

How do lichens respond to environmental stressors like pollution?

Certain lichen species are sensitive to pollutants, such as acid rain, making them good indicator species of environmental change.

What role do soredia and isidia play in lichen reproduction?

Soredia and isidia are structures that allow some lichens to reproduce asexually, generating clones by carrying both algal cells and hyphal material.

What types of chemical tests are used in lichen taxonomy?

Chemical tests using potassium hydroxide, acids, and reagents are performed to determine lichen species based on color changes or crystal formations.