a study of lichen growth in the Canadian Rockies showed that Xanthoria elegans(pictured) expands at a rate of 0.5 mm per year for the first century before slowing down?
Question 5: Among the ascolichens, ________ are produced in spore-producing bodies, the three most common spore body types are the apothecia, perithecia and the pycnidia.
Question 6: Many lichens produce secondary compounds, including pigments that reduce harmful amounts of sunlight and powerful toxins that reduce ________ or kill bacteria.
Question 7: Two obstacles are often encountered when eating lichens: lichen ________ are generally indigestible to humans, and lichens usually contain mildly toxic secondary compounds that should be removed before eating.
Question 8: Lichens also sometimes contain structures made from fungal metabolites, for example crustose lichens sometimes have a ________ layer in the cortex.