All Weeks Gut Check: Exploring Your Microbiome Coursera Quiz Answers
Gut Check: Exploring Your Microbiome Week 01 Quiz Answers
Introduction to Microbes and the Human Microbiome Quiz Answers
Q1. True or False? You have more microbial cells in your body than human cells.
Q2. What is the main difference between bacteria and archaea?
- They perform different cellular functions
- They never live in the same places
- Bacteria can be multi-cellular
- They have different appearances
Q3. Babies born by C-section have gut microbial communities that look most like their mom’s:
- Vaginal microbiota
- Fecal/gut microbiota
- Oral microbiota
- Skin microbiota
Q4. What does “human microbiome” refer to?
- The interactions between microbes associated with humans
- The tiny environment on and inside humans where microbes live
- The microbial community associated with humans
- The collective genes of the microbial community associated with humans
Q5. Why are viruses on the border of what we consider living?
- They have no nucleus
- They have no cilia
- They cannot reproduce without infecting a cell
- They are very tiny
Q6. True or False? The oral and fecal microbial communities from one person look more similar to each other than the oral microbial communities from two different people.
Gut Check: Exploring Your Microbiome Week 02 Quiz Answers
Studying the Microbiome Quiz Answers
Q1. What does “The Great Plate Count Anomaly” describe?
- Culturing microbes on a petri dish makes it impossible to count them
- It takes so long to count microbes on a petri dish that scientists would never finish if they studied communities this way
- For the same sample, more microbes can be counted under the microscope than when grown on a petri dish
- In the past, scientists needed so many petri dishes to culture microbes that they would lose count
Q2. For the first time, Koch’s postulate stated:
- that microbes are everywhere
- that microbes can cause disease
- that most microbes are hard to grow
- that microbes exist on people
Q3. True or False? Polymerase chain reaction (PCR) mimics DNA replication in nature, but it uses primers to copy only one gene of interest in each microbe.
Q4. What is the purpose of the “reversible blocking agent” used during DNA sequencing?
- It ensures that only one nucleotide is added to the sequence at once
- It unzips the DNA during sequencing
- It ensure that only the gene of interest is sequenced
- It stops the sequencing process if too many sequences are created at once
Q5. True or False? The 16S rRNA gene is found in all living organisms.
Q6. In microbiome research, proteomics refers to the study of:
- RNA translated from DNA blueprints by microbes
- Metabolites produced by a microbial community
- Proteins constructed by microbes from DNA blueprints
- All of the genes present in a microbial community
Q7. True or False? Shotgun metagenomics provides us with the same information as 16S microbial community analysis, plus additional information about other microbial genes.
Gut Check: Exploring Your Microbiome Week 03 Quiz Answers
Making Sense Out of Microbial Data Quiz Answers
Q1. True or False? Bacteria are easily identified by morphology because each bacterium looks very unique
Q2. We use the 16S rRNA gene to assign taxonomy to bacteria because:
- It is highly conserved, evolving very slowly, which allows for classification of taxa in the highly diverse domain of bacteria
- It is a gene that is only found in some bacteria
- It evolves very quickly
- It is a gene that does not amplify very well with polymerase chain reaction
Q3. What is the purpose of rarefying samples?
- To ensure even sampling across samples and studies to make comparisons more valid
- To eliminate taxa that are only present in very small quantities and might introduce noise
- To make the samples more heterogeneous and increase the statistical power of the comparisons
- To reduce the amount of data so that it is easier to process
Q4. Why do we need so many sequences per sample for gut microbiome research?
- Because the gut is more diverse than other environments such as the soil
- Everyone has the same gut bacteria so differences are difficult to detect
- Gut microbial communities are very diverse and must be sampled deeply to be described accurately
- Because advances in technology make it harder to collect fewer sequences per sample
Q5. What is beta diversity?
- A measure of the heterogeneity of microbes in one sample compared to another
- A measure of the dissimilarity of microbial communities between two different samples
- A measure of how many microbes in a sample are radioactive
- A measure of how many microbes are dominant in each sample
Q6. What is dimensionality reduction?
- Finding a view of the data that maximizes how different groups of samples that come from people with different diseases appear
- Choosing a smaller number of samples that make patterns in the data more visually apparent
- Identifying microbes that live only on surfaces
- Finding a new presentation of the data that captures the same patterns in the data in fewer dimensions
Gut Check: Exploring Your Microbiome Week 04 Quiz Answers
The Human Gut Microbiome and Your Health Quiz Answers
Q1. True or False? People living Westernized lifestyles (e.g. in the U.S.) have gut microbiomes that are very different from people living more traditional lifestyles (e.g. rural agrarian)
Q2. True or False? A fecal transplant can be considered a type of probiotic
Q3. Which of the following is a true statement about the effect of antibiotics on the gut microbiota?
- Antibiotics alter the gut microbial community differently depending on the person
- Antibiotics have a small effect whereas vaccines have a huge effect
- Antibiotic effects don’t last very long
- Antibiotics only alter the bad microbes
Q4. Disease is often associated with:
- No change in gut microbial diversity
- Dramatic changes from day to day in gut microbial diversity
- Increased gut microbial diversity
- Reduced gut microbial diversity
Q5. Fusobacterium has been linked with colon cancer because:
- People with colon cancer have less of it
- It is found in high abundances near tumors in the colon
- Healthy people don’t have it
- People with more of it develop colon cancer
Q6. The gut microbiota of the elderly is characterized by:
- Low diversity and low stability
- High diversity and high stability
- High diversity and low stability
- Low diversity and high stability
Q7. How do antibiotics affect weight?
- Antibiotics make older people gain more weight because they are mainly designed to kill the bacteria that can harm young children but that are beneficial in the elderly
- Antibiotics make you lose weight because they kill the bacteria that help you digest food
- Antibiotics have no effect on weight because they kill only the bad bacteria that can’t metabolize our food
- Babies treated with antibiotics within the first six months of life end up weighing more
Q8. What happens when we put gut microbes from an obese human into germ-free mice?
- The mice stay the same weight
- The mice lose weight
- The mice die
- The mice gain weight
Gut Check: Exploring Your Microbiome Week 05 Quiz Answers
Gut Microbe-Host Interactions: Beyond Nutrition Quiz Answers
Q1. Why do scientists use mouse models in experiments?
- Mice and humans share 100% of their genomes
- There is no good reason – scientists have just always done it
- Adult mice are naturally germ free, even when raised in a conventional facility that is not germ free
- They allow us to control for genetics and other factors that are difficult to control for in humans and permit experimental replication
Q2. True or False? After death, microbes change in a succession-like or clock-like manner
Q3. Leaky gut refers to:
- Diarrhea after consumption of certain synthetic fats, such as olestra
- Bacteria passing across the gut epithelial membrane
- Food passing across the gut into the bloodstream more than it should
- Short-chain fatty acids getting into the gut epithelium
Q4. Which of these is not true? Germ-free mice have:
- Similar immune activity to normal mice
- Increased rates of infection
- Reduced immune activity
- Fewer immune cells
Q5. True or false? Altering the gut microbiota of mice can affect their level of aggression as well as depression
Q6. What is a difficulty with gut microbiome research and autism?
- So many children have mild autism today that it is difficult to find neurotypical controls
- Autism is associated with GI tract issues, and it’s hard to find controls that have the same GI tract issues but are neurotypical
- Different neurotransmitters are used in the gut and the brain
- Autism is a brain disease, which the gut microbiome cannot affect
Q7. What is one hypothesis for why Pakistani children have fewer food allergies than Swedish children?
- They are exposed to a wide range of spicy food as children
- They live in a warmer climate, where allergies are rare
- They are colonized by gut microbes more quickly after birth
- They eat a strictly vegetarian diet
Q8. Which hormone has been linked to the development of diabetes in mice via interactions with the gut microbiome?
Gut Check: Exploring Your Microbiome Week 06 Quiz Answers
What’s in the American Gut Quiz Answers
Q1. What are the major trends we see in the human microbiome?
- Different body sites generally host different communities of microbes (e.g. the gut has more Firmicutes than the skin on average)
- A person’s microbiome is similar in his or her mouth, gut, and skin
- A person’s diet does not affect his/her microbiome
- A person is born with a certain microbiome, and it does not change as he/she ages
Q2. True or False? Metadata (e.g. information about age, diet, BMI) is not very important for studying the human microbiome
Q3. What is a major issue with even well-funded gut microbiome projects to date?
- Not enough people are willing to participate so nothing can be discovered
- The government decides who can and can’t have their microbiome sequenced
- They use limited populations that don’t well-represent an “average person”
- There are so many microbes that seqeuncing their DNA is impossible
Q4. Who funds the American Gut Project?
- Federal grants
- Large donations from private foundations
- The state of Colorado and the University of Colorado
- Participants, via crowd-funding
Q5. Why does it take so long to process skin samples donated to the American Gut Project?
- Skin microbes are not a high priority because the gut microbes are richer in biomarkers
- Skin microbes are harder to extract than fecal microbes
- The skin doesn’t usually have microbes associated with it except in sick people
- We have to wait for enough people to donate samples so that we can fill a whole DNA extraction plate
Q6. Which of these is NOT a factor that would slow your sample analysis for the American Gut Project
- You did not answer all the questions in the survey
- You didn’t log your sample
- You didn’t fill out your consent
- Your sample has too little material for sequencing
Q7. What is the difference between your most abundant and your most enriched microbes?
- Abundant microbes are fed by the food you eat while enriched microbes feed on your body
- Abundant microbes have fewer metabolic pathways than enriched microbes
- Abundant microbes are the ones you have the most of while enriched microbes are the ones you have more of compared to an average person
- Abundant microbes are found on only a few people while enriched microbes are found on most people
Q8. True or False? Samples collected for the American Gut Project generally match up with samples collected for the Human Microbiome Project at each body site