Which of the following experiments could test the hypothesis that...

Question

Which of the following experiments could test the hypothesis that bacteria cause ulcers in humans? (Assume each experiment includes a control group.) Explain what evidence would be provided by the results of the experiment.
a. Identify the microbes found in the stomachs of ulcer patients.
b. Treat a group of ulcer patients with antibiotics.
c. Place a group of ulcer patients on a strict low-acid diet.
d. Obtain stomach fluid from ulcer patents and feed it to mice.

Accepted Answer

Hi everyone welcome back. Here's our next question. It says which of the following bacteria causes stomach ulcers. Um This is kind of an interesting thing which is that it used to be thought that stomach ulcers were caused by the result of eating things like spicy foods or being stressed. And it was discovered that no it's actually a specific bacteria being infected with. That bacteria can cause stomach ulcers and that bacteria is choice. E. Helicobacter pylori or H. Pylori. As a result of that discovery stomach ulcers can be healed by the use of antibiotics to get rid of the H. Pylori infection. Um There a gram negative s shaped rod bacteria. Um As you know it's pretty difficult for bacteria to survive in that very acidic environment of the stomach. They actually um produce their own ammonia with the activity of an enzyme they have and that ammonia neutralizes stomach acid so as the stomach acid enters the outer membrane of the bacteria their own ammonia neutralizes it and prevents the H. Pylori from being damaged allows it to colonize the stomach. So let's just look through our other answers. We've got our correct answer but understand why they are incorrect choices lactobacillus be as bifida bacterium. These are both beneficial gut bacteria. They live in our intestines. Um Actually our promote gut health and you can buy them in a store as probiotics. So not our answer. They do not cause cultures they're good for us. And finally choice D. S. Curricula coli or e. Coli. Um very famous as causing being able to cause severe food poisoning severe illness sometimes even death when food is contaminated with harmful varieties of E. Coli. But most varieties are actually harmless or even beneficial and well quite harmoniously in a symbiotic relationship with humans in the human intestines. But of course there's a few very harmful strains that get in the news regularly contaminating food but not the cause of stomach ulcers. So not our answer. So again which of the following bacteria causes stomach ulcers that would B. Choice C. Helicobacter pylori. See you in the next video.

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