BioFinal2

Select all statements that accurately describe results obtained through the human microbiome project and other human microbiome studies. The human microbiome varies significantly among individuals. Autoimmune disease is determined entirely by the genes one inherits. Obesity is associated with limited microbial diversity in the gut. The gut microbiome is essential in stimulating immune system maturation.

The human microbiome varies significantly among individuals. Obesity is associated with limited microbial diversity in the gut. The gut microbiome is essential in stimulating immune system maturation.

Which of the following is not a benefit of bifidobacteria colonization in infants? Their fermentation end-products lower the gut pH, inhibiting pathogen growth They bind and internalize sugars, fermenting them to calorie-rich molecules for the infant They synthesize all amino acids and growth factors They provide a reducing environment to enhance the growth of aerobes

They provide a reducing environment to enhance the growth of aerobes

With ideal environmental factors, the reproduction rate of many bacterial species is _________ extremely slow somewhat slow somewhat rapid extremely rapid

extremely rapid

Foods can be spoiled by both intrinsic and extrinsic factors. Extrinsic factors can include things such as _________ pH nutrients storage temperature biological barriers (e.g., shells) water availability

storage temperature

The main environmental factors that affect microorganism growth include chemical inhibitors, oxygen, pH, nutrients, moisture, and _________ food texture time temperature cleaning agents

temperature

The broad basis of the relationship between microbes and cancer in the human host is _________ the ability of microbes to cause high levels of acute inflammation that leads to tumor formation the ability of microbes to halt the normal cell cycle in host cells the ability of pathogens to suppress the normal function of the microbiome the ability of microbes to disrupt the normal cell cycle and to damage or mutate DNA

the ability of microbes to disrupt the normal cell cycle and to damage or mutate DNA

Humans are holobionts; they contain approximately as many microbial cells as human cells. Recent metagenomic investigations reveal that human microbial flora is extremely diverse and is best described as _________ vital to our survival a parasitic relationship occasionally beneficial to the host a cooperative relationship

vital to our survival

Various chemicals are used to preserve food and prevent microbial spoilage. If you wanted to prevent Clostridium botulinum spore germination in your sausage meat, it would be best to use ________. citric acid sodium nitrite sodium propionate lactic acid

sodium nitrite

The Food and Drug Administration uses the acronym "GRAS" to describe chemical preservatives. The ambiguity of the term "generally recognized as safe" may be questionable in light of the fact that _________ all chemicals are dangerous to humans on some level sodium nitrite is toxic in animals and humans, and poses a probable cancer risk when combined with amines found in high-protein foods such as fish, fermented foods such as cheese and wine, as well as certain fruits and vegetables certain gases, such as ethylene oxide, that are used as preservatives, are able to diffuse into food items and are known toxins at high concentrations acetic acid causes stomach cancer

sodium nitrite is toxic in animals and humans, and poses a probable cancer risk when combined with amines found in high-protein foods such as fish, fermented foods such as cheese and wine, as well as certain fruits and vegetables

At freezing temperatures, most bacteria _________ are destroyed stop growing, but are not dead are not affected by the cold grow rapidly

stop growing, but are not dead

Pasteurization is the use of heat to kill both pathogens and spoilage organisms. It's commonly used for treatment of milk. For the high-temperature, short-time (HTST) process, milk is treated at _________ 62.8°C for 30 minutes 72°C for 15 seconds 138°C for 2 seconds

72°C for 15 seconds

A feasible use of probiotics in the future includes _________ a microbial preparation administered in hospital to prevent growth of a population of resistant bacteria travelers taking a prophylactic dose of probiotics in preparation for a trip to a developing country that lacks strict food and water sanitation post-antibiotic therapy, patients are given a dose of probiotics to repopulate the gut to normalize gastrointestinal and immune function All of the choices are correct.

All of the choices are correct.

To date, probiotics have successfully been used in humans, but not animals. True or False

False

Which of the following statements is false regarding the control of microbial growth by altering the availability of water? Dried foods have minimal available water for organisms, however, xerophiles thrive in these dry environments. Foods with a high salt content dehydrate nonhalophiles because of high osmotic pressure, preventing spoilage by most organisms. Foods with a high sugar content have low awaw values, however osmophiles can still spoil these foods. Foods with a high sugar content such as honey, jams and jellies, and syrup, have a high awaw value, which eliminates the growth of microbes.

Foods with a high sugar content such as honey, jams and jellies, and syrup, have a high awaw value, which eliminates the growth of microbes.

How does high-oxygen modified atmosphere packaging preserve food? It prevents the growth of anaerobes like Clostridium botulinum It reduces the water activity in the food, thereby limiting bacterial growth It stimulates the formation of radical oxygen species in contaminating microorganisms It changes the pH of the food, thereby limiting bacterial growth of contaminating microorganisms

It stimulates the formation of radical oxygen species in contaminating microorganisms

Which of the following products are prepared using yeast-lactic fermentation? Kimchi Kefir Champagne Sauerkraut Cheese

Kefir

Identify a microorganism used in probiotic food. Lactobacillus E. coli Campylobacter Leuconostoc

Lactobacillus

Above 100°C (212°F) most bacteria _________ are destroyed stop growing, but are not dead are not affected by the heat grow rapidly

are destroyed

Although the human colon may be one of the most diverse microbial communities on Earth, the majority of the bacteria are classified as _________

anaerobes

The importance of the human gut microbiota on metabolism is that _________ human cells metabolize relatively few molecules into usable calories; most of our cellular energy is derived from microbial metabolism it allows humans to eat large amounts of food without gaining weight regardless of the metabolic biproducts produced by the microbiome, host metabolism is unaffected it is consistent from person to person providing a basis for accurate study

human cells metabolize relatively few molecules into usable calories; most of our cellular energy is derived from microbial metabolism

A fundamental pathology of metabolic syndrome stems from _________. large waist circumference lack of exercise poor diet insulin resistance

insulin resistance

Bifidobacteria are an essential component of host defense against pathogens and are required for _________ normal development of GALT activation of inflammatory responses activation of phagocytic cells degradation of complex carbohydrates

normal development of GALT

On the skin, Propionibacterium acnes converts lipids secreted by the oil glands to unsaturated fatty acids, such as _________ _________, that have strong antimicrobial activity against Gram-negative bacteria and some fungi.

oleic acid