Which technique is commonly used for the qualitative method in microbiome studies?

• 16s rRNA sequencing

What is the main advantage of using the 16S rRNA gene for bacterial identification?

• It is large enough to enable discrimination between species

How are the conserved regions of the rRNA molecule utilized in microbiome research?

• They are used for PCR amplification

What are the larger regions of overlapping sequences called in metagenomic sequencing?

• Contigs

What does the branch in a phylogenetic tree represent?

• The relationship between the taxa in terms of descent and ancestry

What is the Ct value in qPCR?

• The cycle number at which fluorescence begins to appear

What does a lower Ct value indicate in qPCR?

• Higher gene abundance

What is synthesized from mRNA during the transcriptomics process?

• cDNA library

What are secondary abiotic mice?

• Mice that have been treated with antibiotics

What is an advantage of using antibiotic-treated mice as a model for studying the microbiota?

• They are less-expensive than germ-free mice

How does the absence of microbes in the environment impact the immune system of germ-free mice?

• It leads to an underdeveloped immune system

What is the main conclusion regarding the effects of microbiota on our health?

• Microbiota have both desirable and undesirable effects

Which of the following vitamins are synthesized by our gut microbiota?

• Vitamin K and Vitamin B12

Which of the following is a sterile site within the body?

• Lymph nodes

What is the significance of finding bacteria in normally sterile sites?

• It is concerning and may indicate infection or disease

How can a shift in the balance between Gram-positive and Gram-negative bacteria indicate disease?

• A shift towards Gram-negative bacteria is associated with peridontal disease and bacterial vaginitis

Which bacteria are predominantly found in the skin microbiota

• Staphylococcus epidermidis and Staphylococcus aureus

Why is the level of microbiota relatively low in the small intestine?

• The rapid transit time of the small intestine prevents

How does the microbiota in the large intestine differ from that in the small intestine

• The large intestine has a more diverse and abundant microbiota.