Module 5 quiz questions

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

The 16S rRNA gene is a genetic marker that is sufficiently large and variable, enabling researchers to distinguish between different species of bacteria based on genetic similarities and differences.

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

The conserved regions of the rRNA molecule serve as templates that allow for PCR (Polymerase Chain Reaction) amplification, which is crucial for isolating and analyzing specific sequences from bacterial populations.

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

In metagenomic sequencing, the larger regions of overlapping sequences are referred to as contigs, which are assembled from shorter sequences to reconstruct the genomes of the studied microorganisms.

What does the branch in a phylogenetic tree represent?

The branches in a phylogenetic tree symbolize the evolutionary relationships between different taxa, reflecting their descent from common ancestors over time.

What is the Ct value in qPCR?

The Ct (cycle threshold) value in quantitative PCR (qPCR) indicates the specific cycle number during which the fluorescent signal first exceeds a predetermined threshold, marking the point at which PCR amplification of the target DNA becomes detectable.

What does a lower Ct value indicate in qPCR?

A lower Ct value signifies a higher abundance of the target gene in the sample, suggesting greater initial quantities of the DNA present before amplification.

What is synthesized from mRNA during the transcriptomics process?

During the transcriptomics process, complementary DNA (cDNA) libraries are synthesized from mRNA, allowing for further analysis of gene expression levels and patterns.

What are secondary abiotic mice?

Secondary abiotic mice are laboratory mice that have been subjected to antibiotic treatment, reducing their natural microbial load and altering their gut microbiota compared to healthy, non-treated mice.

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

Using antibiotic-treated mice as a model for microbiota research is advantageous because it is more cost-effective than using germ-free mice, which require more extensive care and specialized conditions.

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

The absence of microbes in the environment leads to an underdeveloped immune system in germ-free mice, as their immune responses rely on microbial exposure to mature and function properly.

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

Studies show that microbiota can have both beneficial (desirable) and harmful (undesirable) effects on human health, affecting various physiological processes and disease susceptibility.

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

Our gut microbiota are capable of synthesizing essential vitamins, particularly Vitamin K and Vitamin B12, which play crucial roles in various biological functions.

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

Lymph nodes are considered sterile sites within the body, typically free from microbial colonization under healthy conditions.

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

The presence of bacteria in normally sterile sites, such as lymph nodes, is concerning and often suggests an underlying infection or disease process that requires further investigation.

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

A shift towards an increased proportion of Gram-negative bacteria is associated with certain diseases, such as periodontal disease and bacterial vaginitis, indicating potential dysbiosis.

Which bacteria are predominantly found in the skin microbiota?

The skin microbiota predominantly consists of Staphylococcus epidermidis and Staphylococcus aureus, which are common inhabitants of human skin and play roles in health and disease.

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

The relatively low level of microbiota in the small intestine can be attributed to its rapid transit time, which limits the opportunity for bacteria to proliferate compared to other sections of the gastrointestinal tract.

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

The microbiota in the large intestine is characterized by greater diversity and abundance compared to the small intestine, where conditions favor a lower variety of microbial species.