Microbiology: A Systems Approach 4th Edition by Marjorie Kelly Cowan

Exercise 26

Critical thinking is the ability to reason and solve problems using facts and concepts. These questions can be approached from a number of angles and, in most cases, they do not have a single correct answer.
a. Looking at the photo of the three plants, explain a symbiotic relationship within the rhizosphere that could account for the observed difference in height among these plants.

b. Many people use animal manure to fertilize their garden crops. Discuss how this application benefits the growing plants, and discuss whether or not it poses any risks to human or environmental health.