Micro Lecture final (Person Questions) NOT FINISHED

Obligate anaerobes are likely to be found in the __________.

colon

The conditions of nutrient availability, pressure, and temperature result in long ______ and thus slow ____.

generation times; growth rates

Many plant species grow better with _______ associated with their roots.

mycorrhizae

Which of the following are intrinsic characteristics of immunogens?

Appropriate physical form

The normal human microbiota has coevolved with humans. This microbiota consists of a wide variety of organisms interacting with each other and with their human host. For a normal, healthy human host, how is/are the majority of these relationships described?

Commensalism & mutualism

Substances that cause an immune system response are called __________.

Immunogens

Saliva contains relatively few microbes compared to other body sites, because __________.

the concentration of antimicrobial enzymes limits their growth

The rhizosphere is __________.

the soil immediately surrounding the root of a plant

In a body of freshwater, the transition between the warmer upper layers and the colder lower layers of water is called the __________.

thermocline

Briefly describe viruses that live in the deep ocean.

Turnover in seawater is relatively rapid; the populations are replaced within a few days or weeks. They are the most numerous biological entities in seawater. Most are inactivated by hydrolytic enzymes or sunlight.

Bacterial degradation of cellulose and fermentation of glucose occur in the rumen of cows, sheep and other ruminant animals. The main source of energy for the fermenters is __________, while the main source of energy for the ruminant is __________.

glucose; volatile fatty acids

Herd immunity can protect __________.

an entire population

All of the following are true of biofilms EXCEPT that __________.

biofilms are composed of only one species at a time

The likelihood of colonization by skin pathogens is ____ when the normal microbiota are present

lower

The evolution of plants that grow on dry land is thought to have depended in part on their development of symbiotic associations with which group of microorganisms?

mycorrhizae

Autoimmune diseases sometimes develop shortly after an infection. This is the case with rheumatic fever. Which of the following is the most likely reason that there is often a relationship between autoimmune disorders and infection?

Some pathogens, like the rheumatogenic strains of S. pyogenes, contain antigens that resemble normal cell surface proteins. As the immune system responds to them, it attacks the cells with similar antigens as well.

Deep sea organisms live in habitats that are characterized by high ___ and low ____.

pressure; temperature

The Hepatitis B vaccine is which type of vaccine?

Subunit vaccine

To help digest sugars, honeybees have _______.

symbiotic gut bacteria

Compared with pure cultures grown in the lab, microbes in nature usually experience a wider range of environmental conditions, more variation in conditions over time, and more contact with other organisms. Therefore, the same organism in nature will __________.

typically grow slower than in pure culture

Place the steps of root nodule formation in the correct order. 1. bacteroid formation 2. nod factor secretion 3. invasion 4. recognition of partners 5. mature nodule

4, 2, 3, 1, 5

Briefly describe bacteria that live in the deep ocean.

A common genus is Pelagibacter. Some types found in the photic zone carry out aerobic photosynthesis. Based upon current knowledge, they are the predominant prokaryotes about 1000 m.

Because there is low availability of organic material or reduced inorganic energy sources, the _____ in these ecosystems is low.

BOD (biochemical oxygen demand)

What is the function of boosters?

Boosters are injections that are given periodically to maintain immunity.

What component(s) make up the structure of a virion?

Capsid & genome

Vaccination has had a significant impact on global health. Vaccination for diseases ranging from pneumonia to smallpox has saved millions in lives and public health costs. In developed countries such as the United States, we may take vaccines for granted as they are typically readily available and affordable. However, it is important to appreciate that the process of vaccine development and testing is extremely lengthy and labor intensive. It is not uncommon for development and testing to take over a decade. In this activity, imagine yourself working in vaccine development at a biotechnology company. You are at the very initial stages of development for a new viral vaccine. At these early stages, an understanding of the adaptive immune response (the antibody response in particular) is essential to your progress on the project. Successful vaccination requires the generation of an antibody response and long-term memory. Mounting this response requires a coordinated series of events. Arrange the following statements in the correct order to describe how an antibody response is generated: T helper cells recognize MHCII/antigen complexes on dendritic cells; B cells (presenting MHCII/antigens) are activated after interacting with Th2 cells; Stimulated by IL-4, T helper cells differentiate into Th2 cells; Dendritic cells process antigens; Dendritic cells present antigens on their surface; B cells differentiate into memory cells and plasma cells.

Dendritic cells process antigens Dendritic cells present antigens on their surface T helper cells recognize MCH11antigen complexes on dendritic cells Stimulated by IL-4 T helper cells differentiate in to Th2 cells B cells are activated after interacting with Th2 cells B cells differentiate into memory cells and plasma cells

Why will the microbiota in the vagina of a woman of reproductive age differ from that of the same woman before puberty and after menopause?

During the reproductive years, the vagina contains significant amounts of glycogen that is fermented by Lactobacillus acidophilus to produce lactic acid, creating an acidic environment. Glycogen is absent before puberty and after menopause.

Vaccination has had a significant impact on global health. Vaccination for diseases ranging from pneumonia to smallpox has saved millions in lives and public health costs. In developed countries such as the United States, we may take vaccines for granted as they are typically readily available and affordable. However, it is important to appreciate that the process of vaccine development and testing is extremely lengthy and labor intensive. It is not uncommon for development and testing to take over a decade. In this activity, imagine yourself working in vaccine development at a biotechnology company. You are at the very initial stages of development for a new viral vaccine. At these early stages, an understanding of the adaptive immune response (the antibody response in particular) is essential to your progress on the project. In designing your vaccine, you will need to choose an antigen or antigens to stimulate the adaptive response. All antigens are not created equal--there are certain characteristics that make more effective antigens. Which of the following best describes why molecules such as glycoproteins are more effective antigens compared to molecules such as starch?

Glycoproteins contain a variety of shapes and subunits that contribute to the overall complexity of the molecule.

Extreme Piezophilic organisms grow best in what type of environment?

High pressure

How does the bobtail squid select only Aliiovibrio fischeri for colonization of the light organ?

It produces nitric oxide in the mucus and light organ.

When H. pylori was first discovered, researchers doubted the finding. It was thought that the acidic environment of the stomach was too hostile for microbes to thrive. Newer research using genetic analysis and culture techniques has revealed that there is a diverse gastric microbiota. Of the options below, what is the only one that does not involve genetic analyses?

Knowledge of growth rates allows researchers to predict responses to changing conditions.

Piezotolerant organisms grow best in what type of environment?

Low pressure

Briefly describe Archaea that live in the deep ocean.

Most of these living below 1000 m are thought to be ammonia oxidizers. Below 1000 m the most common phylum is Thaumarchaeola. They increase to near 50% of total prokaryotes below 1000 m.

Piezophilic organisms grow best in what type of environment?

Neither high nor low pressure

Paul had chicken pox when he was 5 years old. Nicholas received the chicken pox vaccines. Which type of immunity does each man have?

Paul has natural active immunity while Nicholas has artificial active immunity.

A small farm pond containing many species of microorganisms (bacteria, cyanobacteria, algae, and protozoa) was perturbed when runoff from a manure pile entered the pond. The added nutrients soon turned the water green due to a bloom of cyanobacteria. How did this affect the microbial community in the pond?

Species richness decreased and species abundance increased.

A protein that can stimulate production of an abnormally large number of T cells and cause host damage is termed __________.

Superantigen

What benefit does the fungal partner get from the lichen relationship?

The alga produces organic compounds as nutrients for the fungus.

Since arbuscular mycorrhizae (AM) have existed before the legume-root nodule associate, why isn't more known about the AM symbiosis?

The fungal partner genetics is largely unknown, the fungal partner can obtain nutrients only from living cells, and the fungal partner cannot be maintained in pure culture in the lab.

In a lichen symbiotic association between a fungus and a cyanobacterium growing on a bare rock surface, the phototroph clearly benefits the fungus by fixing carbon from CO2. The fungus benefits the cyanobacterium in ALL BUT which of the following ways?

The fungus oxidizes organic matter, providing CO2 to the cyanobacterium.

When an individual previously sensitized to ragweed pollen encounters this allergen, what are the steps that lead to typical allergy symptoms?

The pollen binds to IgE molecules, causing degranulation of mast cells, which release mediators that cause the allergy symptoms.

Vaccination has had a significant impact on global health. Vaccination for diseases ranging from pneumonia to smallpox has saved millions in lives and public health costs. In developed countries such as the United States, we may take vaccines for granted as they are typically readily available and affordable. However, it is important to appreciate that the process of vaccine development and testing is extremely lengthy and labor intensive. It is not uncommon for development and testing to take over a decade. In this activity, imagine yourself working in vaccine development at a biotechnology company. You are at the very initial stages of development for a new viral vaccine. At these early stages, an understanding of the adaptive immune response (the antibody response in particular) is essential to your progress on the project. One of the foundations of vaccination is generating an antibody response against your virus. The antibody response is one part of the adaptive immune response. Which of the following are characteristics of an adaptive immune response?

The response has memory, is inducible, clonal, and specific.

When a child begins to get its first teeth, what happens to the microbiota in the oral cavity?

The teeth are rapidly colonized by anaerobes, in particular Streptococcus, that are specifically adapted to growth in biofilms on the surfaces of the teeth.

Which of the following describes a retrovirus?

The virus uses reverse transcriptase to make DNA from an RNA template, the reverse of the normal process of gene expression.

Why is there such a difference between the microbiota in the duodenum and that in the ileum?

There is a large pH difference between these regions of the small intestine.

Collectively, metagenomic studies of the human microbiome have shown ALL BUT one of the following statements are true.

There is no general pattern of similarity in the microbiomes of humans; they are unpredictable.

What is the hallmark of a conjugated vaccine?

These vaccines contain weakly antigenic elements plus a more potent antigenic protein.

Considering that they require an oxygen-free environment, how do obligate anaerobes survive in the human body?

They are able to survive in places where aerobic organisms quickly use the available oxygen. They can also survive in areas with impaired blood flow (reducing oxygen availability).

How are viruses different from cells?

They require a host in order to reproduce.

What is the function of the structural elements of a virus?

To package & protect the viral genome

A woman mentions to her physician during a prenatal check-up that she plans to clean her house from "top-to-bottom" before the baby arrives, and intends to protect her newborn from as many "germs" as possible to prevent any possible infections. If you were the physician, how would you advise this patient?

Too much cleanliness can be a bad thing for an infant, as the bacteria they acquire at an early age help to "train" the immune system to correctly recognize pathogens but not attack beneficial bacteria in the body. Attacking the "normal" bacteria and nonharmful substances can cause too much inflammation, allergies, or asthma later in life.

Some viruses are associated with cancer. There are a variety of ways in which viruses may affect a cell in a way that may lead to the formation of a tumor. Based on your knowledge of the life cycles of viruses and of molecular genetics, what is one way that this might happen?

Viral genetic material inserts into a host genome, placing a promoter in a new location and turning on a gene that had previously been turned off.

Which of the following is NOT a way in which viruses are different from living organisms?

Viruses are obligate parasites and no living organisms are obligate parasites.

Which of the following could describe a virus?

a particle composed of a protein capsid surrounding single-stranded DNA

The mouse model of obesity suggests that __________ is linked to increased body mass.

a reduction in Bacteroidetes

Symbionts can be acquired by an individual host organism horizontally (from the environment) or vertically (from a parent). In humans, there is evidence that infants are largely colonized by their parents' microbes, and family members living in the same household have microbiomes that are more similar than those of individuals living nearby. However, no two humans have identical microbiota, and certain factors, such as diet and antibiotics, can alter the microbiome. This indicates that humans may be colonized by __________.

both vertical & horizontal transmission

You would like to determine the rate of production of carbon dioxide in a specific microbial habitat. How could you do this without growing the microorganisms in the lab?

by using a microsensor

What structure can the viral genome take?

ds-DNA, ss-DNA, ds-DNA

The type of mycorrhizae found associated with forest trees like pines is __________.

ectomycorrhizae

C. difficile infections are on the rise, both in elderly hospitalized patients receiving antibiotics and in younger populations having no previous contact either with a hospital environment or antibiotics. What is the most effective treatment for chronic C. difficile infections?

fecal transplants from a healthy donor

Lichens consist of algae or cyanobacteria and _______.

fungi

A person would be most at risk of infections if he or she __________.

is a 70-year-old alcoholic whose spouse just died

The ______ contains 13-69 epibionts and a flagellated bacillus..

green sulfur bacterial consortium

Free flu shots were given at school, but 3 of the 30 students were absent that day. The next week Bob started showing signs of the flu but was diagnosed with a different viral infection. None of the other students contracted the flu either, even those who missed the shot. This can be explained by __________.

herd immunity

Legumes contain __________ in nodules.

nitrogen-fixing bacteria

One advantage of a monogastric digestive system is that __________.

nutrients are easily accessible to the microbes that aid in digestion and vitamin production

Deep sea sediments are typically _____, having very low nutrient availability.

oligotrophic

Deep sea ocean ecosystems in the region of hydrothermal vents typically have much higher biomass with greater presence of larger eukaryotic organisms than other deep sea ecosystems. Which of the following is most responsible for this difference?

presence of substantial amounts of highly reduced inorganic compounds and methane

Termites are capable of digesting cellulose and hemicellulose due to the presence of __________.

symbiotic bacteria in their gut

Which type of vaccine could possibly cause a person to develop the disease?

Attenuated live vaccine

All of the following are Gram-positive genera typically found on the skin EXCEPT __________.

Bacteroides

The colon has been described as a living fermentation vessel. Which type of culture system would it most resemble?

Continuous culture

Which of the following is an example of artificially acquired passive immunity?

Someone suspected of exposure to Clostridium tetani is given an injection of antibodies (antiserum).

Vaccination has had a significant impact on global health. Vaccination for diseases ranging from pneumonia to smallpox has saved millions in lives and public health costs. In developed countries such as the United States, we may take vaccines for granted as they are typically readily available and affordable. However, it is important to appreciate that the process of vaccine development and testing is extremely lengthy and labor intensive. It is not uncommon for development and testing to take over a decade. In this activity, imagine yourself working in vaccine development at a biotechnology company. You are at the very initial stages of development for a new viral vaccine. At these early stages, an understanding of the adaptive immune response (the antibody response in particular) is essential to your progress on the project. There are a variety of lymphocytes involved in the adaptive response, each with a specific function. One of the subsets of cells essential in the adaptive response is T helper cells. Choose the answer that most accurately describes the role of T helper cells in mounting the antibody response.

T helper cells aid the antibody response by binding to the B cell MHCII/protein complex and secreting cytokines like IL-4.

Although it is important to study the organisms that live in the abyssal and hadal zones, researchers can often more easily study organisms that live closer to the ocean's surface, which do not require the use of remotely operated vehicles and similar equipment for sampling. The photic zone is the region in which the light intensity is sufficient for photosynthesis to occur. In the open ocean of tropical and subtropical regions, the photic zone is dominated by several ecotypes of the bacterium Prochlorococcus. Each ecotype dominates a particular depth range of the photic zone. Which of the following reasons are thought to be responsible for this phenomenon?

The ecotypes differ in ability to photosynthesize and compete effectively at different light intensities. The ecotypes vary in ability to compete for different nitrogen and phosphorus sources.

Plaque assays are often used to estimate the number of virions in a sample of a particular volume (the titer). The count is given as plaque-forming units. Which of the following is NOT generally a concern that must be considered in evaluating the results of plaque assays?

The largest problem is that single viruses may create multiple plaques, resulting in overestimates of the number of viruses present.

An individual has a child who is immunocompromised while undergoing medical treatment. As a result, the child's pediatrician recommends that no one in the family get a particular vaccine. Which of the following most likely describes the vaccine in question?

The vaccine contains an attenuated virus.

Antibiotics are commonly used to treat bacterial infections, although they must be used carefully due to the risk of antibiotic resistant strains. When H. pylori causes symptoms, it is often treated with a medication to make the stomach less acidic (such as a proton pump inhibitor) and with a combination of antibiotics (using more than one reduces the likelihood that resistance will develop). The chapter describes how the use of oral antibiotics can affect the gut microbiota and contribute to the development of Clostridium difficile infections. Do you think that the use of topical antibiotics on the skin affects the normal skin microbiota?

Yes, because the antibiotics may encourage the growth of antibiotic-resistant species. Yes, because the normal microbiota help to prevent colonization by pathogenic species.

An organic farmer is having problems with a particular insect pest in his fields and has consulted the local agricultural extension office for possible solutions. He cannot use pesticides on his fields if he is to maintain his organic certification. You are consulted about the possible use of an entomopathogenic nematode as a means of controlling the insect pest. You need to consider ALL BUT which of the following?

You must be wary of the nematode killing beneficial insects like pollinating bees, because they are generalist pathogens.

Organisms that colonize skin __________.

are mostly gram-positive bacteria

When determining the number of virus particles in a suspension, why is the number obtained always less than the actual viral titer?

because all of the virus particles do not infect with 100% efficiency

Vaccination has had a significant impact on global health. Vaccination for diseases ranging from pneumonia to smallpox has saved millions in lives and public health costs. In developed countries such as the United States, we may take vaccines for granted as they are typically readily available and affordable. However, it is important to appreciate that the process of vaccine development and testing is extremely lengthy and labor intensive. It is not uncommon for development and testing to take over a decade. In this activity, imagine yourself working in vaccine development at a biotechnology company. You are at the very initial stages of development for a new viral vaccine. At these early stages, an understanding of the adaptive immune response (the antibody response in particular) is essential to your progress on the project. During the adaptive response, the MHC molecules are responsible for presenting an antigen to T cells. The two types of MHC (MHCI and MHCII) have specific roles during the response. Which of the following most accurately describes the characteristics of MHCII molecules in mounting the antibody response?

found on APC, present exogenous antigens, activate T helper cells

Bacteria in the small intestine thrive in _____ pH than stomach bacteria

higher

In general, ____ temperature in specific body regions under normal (healthy) circumstances is associated with lower microbial diversity.

higher

The occurrence of colonization by pathogens is ______ in mucous membranes than in unbroken skin.

higher

The occurrence of opportunistic infections is ______ in immunocompromised patients.

higher

Fluorescent in situ hybridization (FISH) can be used to determine __________.

how many Salmonella typhimurium cells are present in a sample of unpasteurized apple juice, the phylogenetic diversity of an environmental sample, and whether a specific piece of mRNA is being produced

The influenza vaccine is an example of a(n)

inactivated killed vaccine.

Benefits of a nodulated plant include __________.

increased plant yield due to nitrogen fixation

A farmer finds that his soybean plants do not look healthy. They appear stunted and the leaves are a yellowish color, indicating possible lack of nitrogen. To have a more successful crop next year, he should consider__________.

inoculating his fields with the appropriate cross-inoculation group of rhizobia

The phylogenetic diversity analysis of complex microbial communities often targets small subunit (SSU) ribosomal RNA genes. This is because rRNA is found in all organisms and __________.

is highly conserved over evolutionary time

Helicobacter pylori is a bacterium found in the stomachs of roughly half of the human population. It is considered to be a pathogen because __________.

it can cause chronic inflammation

Which of the following was a downfall of the Human Microbiome Project?

lack of subject diversity

The presence of microbes in the bladder is __________.

likely to lead to a UTI

Deeper tissues have a ____ diversity of microbes than is found on the skin

lower

H. pylori, bacteria that live in the stomach, thrive in ____ pH than skin microbes

lower

In general, _____ moisture levels are associated with lower microbial diversity.

lower

The colonization of a newborn's gut is influenced by __________.

method of delivery & source of nutrition

Some lichen symbionts can survive independently on bare rocks in the absence of any external source of organic matter due to the ability of the phototrophic partner to fix CO2 from the air, and __________.

nitrogen fixation by the cyanobacterial partner

A higher number of methanogenic Archaea are found in the guts of mice and humans who are obese. It is thought that the methanogens help to foster obesity by__________.

using H2, thus allowing further fermentation of substrates