Name __________________ Period _________Date ________________
QUESTIONS to accompany: THE BACTERIA BEHIND ULCERS
Scientific American, February 1996
1. What causes ulcers?
2. Why did drug companies promote the idea that stress and stomach acids cause ulcers?
3. Describe the research that linked H. pylori to stomach cancer.
4. How is H. pylori adapted to life in the stomach?
5. What is the evolutionary advantage for H. pylori to produce a “slow” chronic infection?
QUESTION: AN ENDANGERED SPECIES IN THE STOMACH
Scientific American, February 2005
1. What is the relationship between genetic variations in H. pylori strains and the geography
and history of human populations?
2. What is the relationship between infection with H. pylori and cancer in the stomach and
esophagus?
3. H. pylori in the stomach may serve a useful role for the host. What diseases are associated
with the eradication of H. pylori? Explain.
4. Humans and H. pylori may be true symbionts. Describe the process of co-evolution in these
two species.
5. The risks and benefits of H. pylori infection may be different for each person. What are the
influencing factor? What information would help doctors determine if H. pylori should be
eliminated or introduced in a patient?