Chapter 30.3, Problem 1CS

Core Skill: Modeling The goal of this modeling challenge is to propose a model that describes the location of algae within a fruticose lichen.

Modeling Challenge: Parts (a) through (c) of Figure 30.11 illustrate three major structural types of lichens: crustose, foliose, and fruticose. Figure 30.11d shows a representative light microscope view of a thin slice of a foliose lichen, which reveals that the green algal cells are located near the upper surface of the flat lichen body. In this location, the photosynthetic cells of the algae are best able to absorb sunlight. Use this information to sketch a structural model of the likely distribution of algal cells in the body of a fruticose lichen. Your model should be a circular cross section through one of the branchlike segments of the lichen. Label the fungal and algal layers.