Problem 10 - AP Psychology Premium Prep 2021

Question

Probiotics are beneficial bacteria or yeast applied to maintain intestinal health in humans or livestock. In theory, these organisms inhabit the intestines and aid in digestion of food. Also, these organisms have bioprotective effects. How can addition of bacteria to the intestine protect the host from disease? (A) Probiotic bacteria crowd the intestine, preventing pathogenic bacteria from growing due to densitydependent limitation on their population. (B) Probiotic bacteria crowd the intestine, preparing a niche for pathogenic bacteria to grow. (C) Bacteria populations grow exponentially until the carrying capacity is reached. (D) Pathogenic bacteria do not recognize the intestinal cells because they are coated with probiotic bacteria.

Step-by-Step Solution

Answer

The correct answer is (A), as probiotic bacteria crowd the intestine, preventing pathogenic bacteria from growing due to density-dependent limitation on their population. This choice best demonstrates the bioprotective effects of probiotics and their role in maintaining intestinal health.

Step 1: Understand Probiotics and Their Function

Probiotics are live microorganisms that, when consumed in adequate amounts, provide health benefits by improving the gut's microbial balance. By aiding in digestion and maintaining a healthy intestinal environment, probiotics may offer bioprotective effects for the host.

Step 2: Analyze the Answer Choices

Now, let's consider each of the four answer choices: (A) Probiotic bacteria crowd the intestine, preventing pathogenic bacteria from growing due to density-dependent limitation on their population. (B) Probiotic bacteria crowd the intestine, preparing a niche for pathogenic bacteria to grow. (C) Bacteria populations grow exponentially until the carrying capacity is reached. (D) Pathogenic bacteria do not recognize the intestinal cells because they are coated with probiotic bacteria.

Step 3: Compare the Answer Choices to the Probiotic Function

We must now compare each answer choice to the known function of probiotics and their bioprotective effects. (A) matches the known function of probiotics, as they maintain a healthy balance of bacteria in the gut. By doing so, probiotics can limit the population and growth of harmful bacteria. (B) does not align with the protective effects of probiotics, as preparing a niche for pathogenic bacteria would be detrimental to the host's health. (C) While it is true that bacterial populations grow until the carrying capacity is reached, this statement does not directly answer how probiotics protect the host. (D) This choice does not accurately represent the known functions of probiotics, as they do not necessarily "coat" intestinal cells, but rather maintain a balanced microbial environment.

Step 4: Select the Correct Answer

Based on the analysis and comparison of the answer choices, the correct answer is (A), as probiotic bacteria crowd the intestine, preventing pathogenic bacteria from growing due to density-dependent limitation on their population. This choice best demonstrates the bioprotective effects of probiotics and their role in maintaining intestinal health.