Question 1

Which of the following best describes the difference between taxonomic diversity and functional diversity in microbiome studies?

Accepted Answer

Taxonomic diversity refers to the variety of microbial species present, while functional diversity refers to the range of metabolic activities and gene functions those microbes perform.

Question 2

In the movie shown in class depicting the changing human infant microbiome, what was the primary method used to obtain the plot data?

Accepted Answer

Sequencing of 16S rRNA genes from stool samples collected at multiple time points.

Question 3

When comparing datasets from the Human Microbiome Project (HMP1), which statement best explains the difference between taxonomic composition and functional profiles across body sites?

Accepted Answer

Taxonomic composition varies greatly between body sites, but functional profiles are more conserved due to similar metabolic requirements.

Question 4

Studies comparing Amerindian and Hadza peoples' microbiomes revealed which major insight?

Accepted Answer

Traditional lifestyles are associated with higher microbial diversity and distinct taxa compared to urbanized populations.

Question 5

Which sequencing strategy is most commonly used to identify microbial taxa in a microbiome sample, and what molecule does it target?

Accepted Answer

16S rRNA gene sequencing, targeting the 16S ribosomal RNA gene.

Question 6

Which microbiome-based treatment has been shown to cure recurrent Clostridioides difficile infection?

Accepted Answer

Fecal microbiota transplantation (FMT)

Question 7

Short-chain fatty acids (SCFAs) such as acetate, propionate, and butyrate are produced by gut microbiota through which process?

Accepted Answer

Fermentation of dietary fibers

Question 8

Which mechanistic link between microbiomes and cancer has been demonstrated in recent studies?

Accepted Answer

Certain gut bacteria can metabolize dietary compounds into carcinogens, increasing cancer risk.

Question 9

Recent data on Cutibacterium phylotypes suggest which alternative explanation for differences in skin microbiomes leading to acne?

Accepted Answer

Specific phylotypes of Cutibacterium are associated with acne, rather than the presence of C. acnes bacteriophage.

Question 10

What important information can be gained from studies of monozygotic and dizygotic twin microbiomes?

Accepted Answer

The relative influence of genetics versus environment on microbiome composition.

Question 11

Which of the following is a major process regulating microbe-to-brain communication in the gut-brain axis?

Accepted Answer

Production of neurotransmitters and signaling molecules by gut microbes

Question 12

According to the Hygiene Hypothesis, why is there an increased incidence of allergies and autoimmune diseases in urbanized societies?

Accepted Answer

Reduced exposure to diverse microbes leads to improper immune system development.

Question 13

Which molecular mechanism is implicated in immune dysregulation driven by the microbiome, leading to allergies and autoimmune diseases?

Accepted Answer

Altered microbial metabolites modulate T cell responses, leading to inappropriate immune activation.

Question 14

In the mini-presentation on breast cancer prediction using the blood microbiome, what was the major difference observed in the microbial profiles?

Accepted Answer

Distinct microbial taxa were found in the blood of breast cancer patients compared to healthy controls.

Question 15

In the Parkinson’s disease gut microbiome study, what did the red and blue clusters in the species network represent?

Accepted Answer

Distinct groups of microbial species associated with either Parkinson’s patients (red) or healthy controls (blue).

Question 16

A researcher wants to test whether microbiome dysbiosis causes a specific disease. Which experiment would provide strong evidence of causation?

Accepted Answer

Transplanting microbiome from diseased individuals into germ-free mice and observing if the mice develop disease symptoms.

Question 17

If a patient with recurrent C. difficile infection receives fecal microbiota transplantation (FMT), which equation best describes the expected change in microbial diversity ($$D) $$over time ($$t$$)?

Accepted Answer

$$D(t) = D_0$ + \Delta D_{FMT}$$

Question 18

Which equation represents the calculation of Shannon diversity index ($$H) $$for a microbiome sample with $$n$$ species and proportions $$p_i$$?

Accepted Answer

$$H = - \sum_{i=1}^{n} p_i \log p_i$$

Question 19

A patient’s gut microbiome is analyzed before and after antibiotic treatment. Which scenario best illustrates dysbiosis?

Accepted Answer

A significant reduction in microbial diversity and loss of beneficial taxa post-treatment.

Microbiomes Mini-Exam 2 Study Guidance

Study Guide - Practice Questions

Study Guide - Flashcards