Microbiology Chapter 1-15
Most prokaryotes are between ________ in size.
0.5 and 2.0 μm
Referring to the following reaction, identify the product of the reaction. 3H2 (g) + N2 (g) → 2NH3 (g)
2NH3 (g)
Based on your knowledge of binary fission in prokaryotes, how many cells would be present after four cycles of cell division if you started with two cells?
32
Your initial inoculum was 200 cells. How many cells would be present after 2 hours if the generation time was 30 minutes?
3200 cells
The following table shows the generation time for an Escherichia coli culture grown at various incubation temperatures. Table 1. Incubation Temperature and Corresponding Generation Times of E. coli Table 1 shows the generation time for Escherichia coli at various temperatures. At 5℃ and 60℃ , the culture does not grow. At 7℃, the generation time is 40 minutes, at 37℃, the generation time is 20 minutes, and at 42℃ , the generation time is 35 minutes. According to the table above, the optimal growth temperature for E. coli is:
37°C
Which of the following best describes the tertiary structure of proteins?
3D globular structures stabilized by covalent disulfide bridges
Eukaryotic ribosomes are made up of a small _________ subunit and large _________ subunit.
40S; 60S
At which temperature would you expect enzymes and proteins of human pathogens to denature?
41°C
Which direction are phosphodiester bonds of DNA usually built in?
5' → 3'
You are administering a 5% dextrose in water solution to your patient to replace lost fluids and provide carbohydrates to the body. How much dextrose was added to 1 liter of water?
50g/L
Which of the following is a correct statement about hemolytic transfusion reactions?
A hemolytic transfusion reaction, which lyses red blood cells, could kill the patient.
Which of the following is the best definition for the term attenuated?
A microorganism that is infectious but is weakened to the point of being unable to cause disease in an immunocompetent host
DSM: Infectious disease commonly follows five basic stages. During which stage would a patient not be able to spread the disease?
A patient may spread an infectious, communicable disease during any of the five stages.
Infectious disease commonly follows five basic stages. During which stage would a patient not be able to spread the disease?
A patient may spread an infectious, communicable disease during any of the five stages.
A healthy gut microbiome contains diverse species where benign microbes help keep pathogenic members in check. Which of the following could tip the balance from normal microbiota to a disease state?
A patient on an intravenous course of antibiotics
Which of the following statements is an example of patient noncompliance that accelarates resistance to antimicrobial drugs? A person obtains antimicrobial drugs without prescription in a developing country. A doctor inappropriately prescribes antibiotics to treat a patient suffering from a cold. A doctor picks up a resistant strain on her scrubs and transfers it to an immunocompromised patient. A patient stops taking his amoxicillin that he was prescribed for strep throat because he felt better after 5 of 10 doses.
A patient stops taking his amoxicillin that he was prescribed for strep throat because he felt better after 5 of 10 doses.
Your pediatric patient recently received a DTaP vaccination, providing immunity to diphtheria, tetanus, and pertussis. If your patient is exposed to pertussis a few weeks following this vaccination, which of the results would you expect to receive when measuring the patient's antibody titers?
A rapid surge in the production of IgG antibody
Which of the following is a major difference between bacteriophages and animal viruses?
Animal viruses enter the host cell; bacteriophages inject their genome into the host without entering.
Nematodes, tapeworms, and flukes are members of the kingdom _________.
Animalia
Which general category of drugs is the most selectively toxic? Antiprotozoan drug Antibacterial drug Antifungal drug Antiviral drug
Antibacterial drug
Which of the following key HAI's is not associated with its correct cause?
Clostridium difficile: Causes acute illness that is followed by a high risk of chronic infection that causes severe liver damage and increases the risk of liver cancer
Which of the following does not represent a shape or arrangement that a prokaryote can assume?
Clusters of bacilli form a Staph arrangement.
Which of the following type of fungal spores arise from mitosis and do not result in genetic variation?
Conidiospores
Which of the following statements about constitutive genes is false?
Constitutive genes produce their proteins when a cell encounters a specific environmental change.
Which microorganism requires the low pH inside a phagolysosome in order to reproduce?
Coxiella burnetii
Which of the following is a bacterium that performs oxygenic photosynthesis?
Cyanobacteria
Which of the following statements about DNA is incorrect?
DNA is a long, single-stranded molecule that curves into a helix, and the set pairings of the bases ensure that there is always a purine across from another purine and a pyrimidine across from another pyrimidine.
Choose the true statement about the epigenome.
DNA methylation patterns of the epigenome can be inherited
Which of the following statements about DNA replication in bacteria is false?
DNA replication proceeds in only one direction around a circular chromosome.
The central dogma states that the primary flow of "genetic information" in a cell primarily proceeds from _______.
DNA to RNA to protein
You are working in a pediatric doctor's office and your 5-year-old patient needs his 5th dose of the diphtheria, tetanus, and pertussis vaccine. Which of the following vaccines would you need to administer?
DTaP
Antipyretics such as ibuprofen and acetaminophen work in which of the following manners?
Decrease production of prostaglandins
The hygiene hypothesis proposes which of the following?
Decreasing diversity of our normal flora from increased antibiotic usage and changes in diet and lifestyle may lead to increased allergies and autoimmune disorders.
Which type of reaction is shown in the picture? The figure shows an example of a chemical reaction in which two reactants are brought together in such a way that water is released.
Dehydration synthesis reaction
Which of the following statements concerning desensitization therapy is true?
Desensitization therapy encourages plasma cells to produce IgG antibodies against the allergen.
DSM: Which of the following is not a responsibility of epidemiologists?
Develop antibiotics
Which of the following is not an accomplishment that is attributed to Louis Pasteur?
Developing the postulates of disease
Choose the false statement about cellular transport mechanisms.
Diffusion is the passive movement of substances from areas of low concentration to areas of high concentration.
Which of the following is an unsuitable culture method for an animal virus?
Direct inoculation of virus onto blood agar
Which of the following factors allows for the best chance of disease eradication?
Disease is preventable through vaccination
Which of the following statements correctly describes Dr. Ignaz Semmelweis's contribution to hospital epidemiology?
Dr. Semmelweis demonstrated that handwashing prior to examining patients cut down on the incidence of nosocomial infections.
An elderly patient who contracted chickenpox as a child now has shingles as an adult. You explain to your patient that both diseases are caused by the same virus, which lays dormant in the body prior to reactivation. Based on this information, choose the true statement.
During dormant periods, the virus exists episomally inside of infected host cells.
DSM: You had dinner with your friend who was suffering from a severe cold. She sneezed a few times, and now you are worried that she transmitted her cold to you. During which of the five stages of disease would you expect first symptoms to appear?
During the prodromal phase
You had dinner with your friend who was suffering from a severe cold. She sneezed a few times, and now you are worried that she transmitted her cold to you. During which of the five stages of disease would you expect first symptoms to appear?
During the prodromal phase
Spontaneous mutations are estimated to occur in one out of every _______ base pairs.
(10 billion)
The sodium ion is noted as Na+ because it has an overall charge of _______.
+1
Which of the following statements regarding tropism is/are true?
- Even if a pathogen successfully invades its preferred host tissue, it may not necessarily cause disease. - Most emerging pathogens have expanded host or tissue range.
Which of the following symptoms and signs of infection are associated with septic shock?
- fever - tachycardia - feeling of disorientation
Which of the following is/are examples of virulence factors?
- flagella - capsule - iron-binding proteins
Why is Celiac disease characterized as a type IV hypersensitivity and not an allergy?
T cells, not IgG, attack the lining to the small intestines within 2-3 days of consuming gluten.
Which of the following is the primary activation signal to fully activate T helper cells?
T helper cell's TCR interacts with the MHCII-antigen complex.
_________ are the most abundant T cells, and their function is to __________.
T helper cells (CD4+); coordinate the adaptive immune response
An APC bearing MHC-antigen complexes on its cell surface migrates to lymphoid tissues and interacts with which of the following cells?
T helper cells and T cytotoxic cells
In desensitization immunotherapy, an antigen is used to stimulate cell 2, which can then stimulate cell 3 and cause the production of item 4. Identify cell 2, cell 3 and item 4.
T regulatory cell, T helper 1 cell, and IgG antibodies
Which T cell class is incorrectly matched with its description?
TC: attack other T cells during self-tolerance screening
Which of the following types of microscopy would be best to study how a novel virus interacts with its host cell?
TEM
Which of the following is an incorrect statement about teichoic acids found in Gram-positive cell walls?
Teichoic acids are not found in the cell wall of a Gram-positive organism; they are only found in Gram-negatives.
Which of the following is a feature true for the adaptive immune response only?
The response is tailored to a specific antigen.
Which of the following statements about feedback inhibition is false?
Feedback inhibition is irreversible.
Rank the following metabolic strategies from least potential ATP gain to greatest potential ATP gain.
Fermentation, anaerobic respiration, aerobic respiration
Which of the following is not an example of first-line defenses?
Fever
While all effects of fever are not entirely understood, some studies have suggested various reasons as to why especially low-grade fevers may be beneficial. Which of the following would not be a function of fever?
Fever works by limiting the production of prostaglandins in the hypothalamus.
Which of the following cellular structures is matched with their correct function?
Fimbriae - allow a cell to stick to surfaces or each other
When an individual's CD4 T cell count drops below 200 cells per cubic millimeter of blood due to infection with Human Immunodeficiency Virus (HIV), an individual is diagnosed with Acquired Immune Deficiency Syndrome (AIDS). Your patient is at an advanced stage of HIV infection. Which of the following methods of cell enumeration would be most definitive for an AIDS diagnosis?
Flow cytometry
Which of the following is (are) mismatched? To be marked correct, you'll need to select all mismatched statements, as there may be more than one correct answer.
Gram stain: turns Gram-negative cells purple Acid-fast stain: turns acid-fast cells blue
Why are chemical agents like lysozyme more likely to damage Gram-positive bacteria than Gram-negative bacteria?
Gram-negative bacteria have an outer membrane as part of their cell wall.
which statement correctly describes endotoxins?
Gram-negative bacteria mainly release endotoxin when they die, although a small amount can be released as the bacteria divide.
_____________ bacteria lack an outer membrane, have a thick layer of peptidoglycan, contain teichoic acid, and lack mycolic acid.
Gram-positive
Which of the following molecules released by cytotoxic T cells will enter a virus-infected cell through pores and break down proteins?
Granzymes
Which of the following type II hypersensitivities is noncytolytic?
Grave's disease
In which organism would you likely find a chlorosome?
Green sulfur bacteria
HIV, the virus which causes AIDS, interacts with two receptors on the host cell membrane: CD4 and CCR5. A small percentage of individuals have a genetic mutation which causes their cells to lack CCR5. These individuals will never develop AIDS nor are they able to pass HIV on to others. Which part of viral replication is being blocked by the lack of a receptor?
HIV cannot attach to the host cell without the proper membrane receptor.
The degree to which the antigen provokes an immune response varies and depends on the antigen's biochemical features. Which of the following molecules are the least immunogenic?
Haptens
Choose the true statement regarding Lister's contribution to health care.
He developed aseptic surgery practices.
Which of the following is not needed to carry out excision repair in Escherichia coli?
Helicase
Which of the following organisms would have enzymes that would function best in a low pH?
Helicobacter pylori
Which of the following is not an autoimmune disease?
Hemolytic disease of the newborn
For which of the following diseases is no vaccine available?
Hepatitis C
Which of the following statements is false?
Immunofluorescence is when fluorochromes bind to a specific target and fluoresce after exposure to UV light.
Why are immunological diagnostic tools a better choice than biochemical tools in identifying a variety of cellular as well as viral pathogens?
Immunologic diagnositics can identify noncellular pathogens like viruses that lack their own biochemical processes.
You are a manufacturer of polypropylene hypodermic syringes. Which of the following methods would be best for ensuring sterility of this heat-sensitive material?
Ionizing radiation
Which of the following is an incorrect statement about iron-binding proteins?
Iron-binding proteins are also referred to as "siderophores."
___________ is the minimum concentration of the drug that kills at least 99.9 percent of the bacteria present. MRSA MIC VRE MBC
MBC
What is the role of MHC I in the immune response?
MHC I is found on all body cells except red blood cells and presents a sample of cellular proteins, including those of any intracellular pathogens, to T cells.
Which statement is not true about MHC II?
MHC II interacts with both the CD4 and CD8 receptors on T helper and T cytotoxic cells.
When "matching" a donated organ or tissue to a recipient, it is necessary that the ________ of the donor and the recipient be as similar as possible.
MHCs
Which of the following antimicrobials does not match its potential shortcomings? Aminoglycosides: Are known to cause irreversible hearing loss when administered other than topically. Tetracyclines: Induce photosensitivity, causes detrimental effects on bones and teeth in children younger than 8 years old, and are associated with an increased risk of Clostridium difficile infection Lincosoamides: One common lincosoamide is associated with pseudomembranous colitis caused by Clostridium difficile. Phenicols: Has a narrow therapeutic index and is associated with bone marrow toxicity that results in aplastic anemia. Macrolides: This narrow-spectrum drug must be administered parenterally.
Macrolides: This narrow-spectrum drug must be administered parenterally.
In terms of personal health, why should vegetarians still care about the misuse of antibiotics in livestock? Livestock live happier lives without constantly eating antibiotics. Manure-contaminated runoff is destroying aquatic life when this runoff gets into local waterways. Food is often cross contaminated but it's better to have an easily treatable GI infection compared to an antibiotic resistant GI infection. Manure-contaminated water and manure-based fertilizers introduce resistant bacteria into the food chain. Recreational water activities become a source of infection when manure-contaminated runoff finds its way into these areas.
Manure-contaminated water and manure-based fertilizers introduce resistant bacteria into the food chain.
Which of the following diseases has seen the strongest surge in the number of cases in the U.S. due to decreasing vaccination rates?
Measles
DSM: Which of the following infectious agents is a reemerging pathogen?
Mycobacterium tuberculosis
Which of the following infectious agents is a reemerging pathogen?
Mycobacterium tuberculosis
Chemoorganoheterotrophic aerobes produce most of their ATP via electron transport with oxygen as the terminal electron acceptor. Which of the following carries electrons during aerobic respiration in chemoorganoheterotrophs?
NADH
Which of the following molecules would not change the pH of an unbuffered solution?
NaCl
Which of the following would not be considered a beneficial characteristic when choosing a new antimicrobial drug? High stability in the human body High selective toxicity Narrow therapeutic index Low drug interactions
Narrow therapeutic index
Which of the following statements concerning natural killer cells is true?
Natural killer cells provide protection against viruses, bacteria, parasites, and tumors.
DSM: Which of the following would be considered a symptom?
Nausea
According to the CDC, Clostridium difficile, carbapenem-resistant Enterobacteriaceae (CRE), and multidrug-resistant strains of __________ are classified as urgent threats. Pseudomonas aeruginosa Campylobacter jejuni Neisseria gonorrhea Staphylococcus aureus
Neisseria gonorrhea
Which of the following microbes would most likely be able to infect a deep wound on a patient?
Neutralophilic mesophiles
Which of the following are not part of the adaptive immune system?
Neutrophils
Which of the following leukocytes are the most numerous in human blood?
Neutrophils
Choose the true statement about post-translational modifications.
Post-translational modifications include phosphorylation, trimming, and addition of organic factors.
Which of the following functional groups is matched with its correct name?
R-OH: hydroxyl group
Choose the correct statement about viral evolution.
RNA viruses mutate faster than DNA viruses due to a lack of proofreading replicative enzymes.
Which special type of PCR would be used to detect RNA in a sample?
RT-PCR
Which of the following infectious agents would not directly infect immune system cells?
Rabies virus
Which of the following is not a subunit vaccine?
Recombinant vector vaccine
Your patient presents to the emergency room with classical signs of Lyme disease, including a bulls-eye rash at the infection site. The patient states that the rash appeared roughly one week after hiking in the woods. The fever began soon after, lasted for three days, resolved for three days, and then came back. Which of the following terms best describes your patient's fever?
Relapsing fever
An activated T helper cell becomes either an effector T helper cell or a memory T helper cell. What is the function of the effector T helper cell?
Release factors that help T cytotoxic cell and B cell activation
Which of the following is true about retrotransposons?
Retrotransposons rely on an RNA intermediate to insert into a new part of the genome.
Which of the following statements about reverse transcription is false?
Reverse transcription requires a particular initiation sequence
Human immunodeficiency virus-1 is an RNA virus with a long incubation period. Due to the long time needed for disease symptoms to develop, disease progression can alternatively be measured by detection of HIV genetic material in the bloodstream of infected patients. Which of the following molecular methods would be most appropriate for disease detection of HIV-1 in patients bloodstream?
Reverse-transcriptase polymerase chain reaction
Which of the following disorders is considered a "Type II" in the Gell and Coombs classification system?
Rheumatic heart disease
Which of the following is an incorrect statement about admininstering RhoGAM to an Rh- mother?
RhoGAM will be administered to every Rh- mother after birth, even if her child is Rh-.
Which of the following statements is false concerning RNA?
Ribonucleotides found in RNA include the same sugar deoxyribose that is found in DNA.
Which of the following is not needed during transcription?
Ribosomes
Which of the following statements is incorrect?
Ribosomes are membrane-bound organelles that aid in protein synthesis.
Which of the following is mismatched?
Ribosomes: central to RNA production in a cell
How are ribozymes different from enzymes?
Ribozymes are made of ribonucleic acid, whereas enzymes are made of protein.
Which of the following statements about ribozymes is false?
Ribozymes have only been shown to act on other DNA molecules.
You would like to sterilize bacterial growth media in a flask. You have about 1.5 hours before your patient's sample will be ready for inoculation. Which method would be best to sterilize the media within the timeframe?
autoclaving
Prokaryotic cells move in response to a wide variety of stimuli. Which of the following types of movement is incorrectly matched?
Tumble - movement in a concerted direction toward or away from a stimulus
Which of the following hypersensitivities are characterized by the slowest onset?
Type IV
Why are type IV hypersensitivities called delayed hypersensitivity reactions?
Type IV reactions manifest slowly over 12-72 hours after the stimulating antigen is encountered.
Which of the following could be used as evidence for spontaneous generation?
Uncovered meat will give rise to maggots.
Which of the following is not a property used to group viruses?
Unicellularity versus multicellularity
Which of the following lipids tends to be liquid at room temperature?
Unsaturated lipids
Which of the following statements is incorrect?
Vaccines cause autism.
___________ are usually found in an atom's outermost shell and tend to participate in chemical reactions.
Valence electrons
Which statement is true about valence electrons?
Valence electrons participate in chemical reactions, and interactions between valence electrons in reacting atoms determine what kind of chemical bond is formed.
Which of the following antibacterial drugs targets the cell wall of bacteria? Ciprofloxacin Vancomycin Clindamycin Polymyxin B
Vancomycin
Which of the following antimicrobial drugs would not be appropriate to treat a patient with walking pneumonia? Tetracycline Vancomycin Levofloxacin Erythromycin
Vancomycin
Your patient has osteomyelitis caused by a strain of Staphylococcus aureus (a Gram-positive bacterium) that naturally produces beta-lactamase. Which of the following treatments would be the most effective? Ampicillin Aztreonam Isoniazid Vancomycin
Vancomycin
Which of the following statements are true about serum sickness?
With serum sickness, the patient's immune system recognizes the administered substance as foreign.
In 1984, in one of the most famous cross-species transplantations, a baboon heart was transplanted into an infant (Baby Fae). This surgery is an example of which of the following types of grafts?
Xenograft
The monomeric structure of an antibody can be described as ________-shaped and is composed of light and heavy chains that are held together by _________.
Y; disulfide bridges
DSM: You have isolated a suspected pathogen in pure culture from a diseased laboratory animal. You are not sure whether that organism is what is causing the disease. Applying Koch's postulates, what would be the next step to find out more about the organism?
You should introduce it back into a healthy animal model, and the organism should display the same symptoms.
You have isolated a suspected pathogen in pure culture from a diseased laboratory animal. You are not sure whether that organism is what is causing the disease. Applying Koch's postulates, what would be the next step to find out more about the organism?
You should introduce it back into a healthy animal model, and the organism should display the same symptoms.
Prokaryotes reproduce via _________.
binary fission
Which is not a step in the process of B cell activation by a T-dependent antigen?
binding of the antigen to a T helper cell receptor
Which of the following drugs are not matched correctly with their mode of action? echinocandin drugs: inhibits fungal cell wall synthesis by targeting an enzyme that makes a component of the fungal cell wall azoles: inhibits ribosome function by entering ribosome as a tRNA, covalently binding to mRNA, and forcing the destruction of the complex allyamines: inhibits enzymes that build ergosterol which leads to improperly built plasma membranes and fungal cell lysis polyenes: directly interacts with ergosterols which causes targeted plasma membranes to become leaky and leads to cell lysis Flucytosine: targets fungal DNA replication by blocking transcription when it is converted to a nucleic acid analog that blocks DNA and RNA synthesis
azoles: inhibits ribosome function by entering ribosome as a tRNA, covalently binding to mRNA, and forcing the destruction of the complex
The primary difference between a biological and a mechanical vector is that:
biological vectors play a role in the pathogen's life cycle, whereas a mechanical vector spreads disease without being integral to a pathogen's life cycle.
T-cell precursors are made in the __________ and mature in the __________.
bone marrow; thymus
Which of the following class of hypersensitivity reactions is not associated with autoimmunity?
allergies
Nonspecific permeases
allow a variety of molecules to cross the cytoplasmic membrane.
bacterial capsules_______________
allow for avoidance of phagocytes
Viral spikes
allow the virus to attach and enter host cells, may be a target for the host immune system, and show specificity in binding to particular structures on the host cell.
The complement system consists of over 30 different proteins that work together in a cascade fashion to protect us against infectious agents. One way this system is activated is via the ____________, when complement proteins are activated by directly interacting with pathogen.
alternative pathway
Neosporin is a topical antimicrobial ointment that is commonly applied to minor scrapes and burns. It contains the antimicrobial agent neomycin. Neomycin is a member of the ______. macrolides phenicols aminoglycosides lincosamides
aminoglycosides
Droplet and airborne precautions
both involve diseases of the respiratory system and/or diseases transmitted through a respiratory route.
Viruses which infect many different tissues types are said to have a(n)
broad tropism.
Most cases of Clostridium difficile infections have been preceded by a prolonged treatment with ___________. antifungals antivirals broad-spectrum antimicrobial drugs narrow-spectrum antimicrobial drugs
broad-spectrum antimicrobial drugs
A pathway that functions simultaneously in both anabolism and catabolism is termed
amphibolic.
The flagellar arrangement seen in the picture can be described as _________.
amphitrichous
An anion is formed when
an atom gains one or more negatively-charged electrons.
Which of the following would not cause serum sickness?
anti-inflammatory drugs
Which of the following are used to treat serum sickness?
anti-inflammatory drugs and antihistamines
compared to direct ELISA, a sandwich ELISA
can be designed to be read without a plate reader, making it suitable for home use.
Nucleic acid detection techniques:
can detect new viruses and early-stage infections that antibody-antigen tests are likely to miss.
The protein shell that packages and protects the genome and also accounts for the bulk of a virion's mass is called a _________.
capsid
Which cell type works to prevent our immune system from attacking self and from over-reacting to nonthreatening substances, is abundant in tissues next to body openings, and phagocytizes a broad range of antigens?
dendritic cells
The building blocks of nucleic acids are _________.
deoxyribonucleotides or ribonucleotides
Which of the following is false about the enzyme lysozyme?
destroys viruses and fungi
Which of the following is not a responsibility of epidemiologists?
develop antibibiotics
A sample obtained from a patient's throat was inoculated on blood agar. After 24 hours, there was a clear yellow zone covering the area of growth. The medium used was _________ and the organism is said to be _________.
differential; beta hemolytic
Postexposure prophylaxis, a form of artificial passive immunity, is often given when a person is bitten by an animal that is suspected of having rabies, or if the rabies-status of the animal cannot be confirmed. What specifically, is being given to the patient in this type of treatment?
antibodies harvested from a host who has developed an immune response to the rabies virus
Which of the following is not required for T cell activation?
antibody
Upon entering the host, the pathogen may conceal antigenic features so the immune system doesn't quickly mount an attack. This is also known as __________.
antigen making
A substance that may trigger an immune response, if presented in the right context is termed a(n)
antigen.
Your patient is suffering from botulism caused by the potent toxin released by Clostridium botulinum. In addition to supportive care, the patient could also receive an ________ to neutralize the toxin and stimulate her
antitoxin; artificially acquired passive immunity
Plants _________.
are multicellular organisms that carry out photosynthesis
The difference between T cell activation by normal antigens and T cell activation by superantigens is that superantigens
are not processed and presented by APCs and cause nonspecific activation of many T cells at once, including those that would not normally recognize the antigen.
Endemic infections
are routinely detected in a population or region.
live attenuated vaccines
are the closet to the actual infectious agent encountered in nature and stimulate potent immune responses to multiple antigens on the pathogen
T-independent antigens
are usually polysaccharides and able to bind multiple B cell receptors on a given B cell.
Pregnant women are usually advised to be vaccinated against influenza to protect themselves and the baby after birth. The mother will acquire ________ immunity from the vaccine while the baby will acquire ________ immunity.
artificial active; natural passive
When practicing aseptic culturing techniques, it is important to keep all of the following in mind except
as long as nothing unintended touches the media, there will be no contamination.
Most prokaryotic cells reproduce _________ through a process called __________.
asexually; binary fission
Which stage of animal virus replication may be blocked by a drug that binds with the viral spike?
attachment
The primary function of the nucleus is
housing the cell's DNA
Which of the following factors does not affect the efficiency of a germicide?
how the object is used
You are working with a substance that readily dissolves in water. It is said to be _______.
hydrophilic
__________ are a collection of tubular structures, either septate or aseptate, which allow for growth in most fungi.
hyphae
Which of the following is not part of the five general steps that a microbe must follow in order to successfully establish an infection?
release endotoxins
Which of the following is not a way that bacteria can evade complement activation?
release enzymes that break down lectins responsible for triggering complement activation
Cytotoxic T cells eliminate pathogens by
releasing chemicals which cause infected or cancerous cells to undergo apoptosis.
What is the role of memory cells?
remain in the lymphoid tissue to rapidly proliferate and differentiate upon subsequent exposure to the same pathogen
Elevated body temperature that fluctuates but does not reach normal during the course of the fluctuations is classified as a _________.
remittent fever
The Golgi apparatus:
resembles a series of disc-like, flattened sacs called cisternae that stack upon one another.
Which enzyme is used to generate compatible sticky ends in order to join a desire gene to a plasmid vector in recombinant DNA techniques?
restriction enzymes
The CRISPR-Cas9 system uses all except which of the following?
reverse transcriptase enzyme
Pregnancy tests are examples of _________.
sandwich ELISAs
Which of the following diseases makes antibodies against centromeres and topoisomerases?
scleroderma
You are interested in the alpha helices present in a novel protein. In order to study them, you must consider the _________ structure of a protein more closely.
secondary
Exotoxins are
secreted and the targets of some childhood vaccines.
Which cell type is the most numerous white blood cell in circulation, is the first leukocyte recruited from the bloodstream to injured tissues, and releases potent antimicrobial peptides?
neutrophils
The picture shows _________ that are commonly elevated during ___________.
neutrophils; acute bacterial infections
A patient antibody titer which shows an increasing level of IgM but very little IgG would likely indicate that
the patient is in the early stages of developing an immune response.
microbes transferred via the ____________ portal of exit(s) would be present in pus or drainage that is easily transmitted to others
otic and skin
Polymyxin B targets the ________ of Gram- ________ organisms. periplasmic space; positive plasma membrane; negative outer membrane; negative peptidoglycan synthesis; positive
outer membrane; negative
Sugar molecules, such as glucose, are _________ during the first steps of energy harvest for a cell.
oxidized
A symbiotic relationship exists between two or more closely connected organisms. The relationship between one organism invading another and causing harm to that organism would be considered _______.
parasitism
A new type of fungal meningitis (infection of the nervous system) was discovered. Disease occurred among patients who had received steroid injections into their spine. What was the portal of entry?
parenteral
Which portal of exit will a bloodborne pathogen likely use?
parenteral
_________ reduces the number of microbes on a given non-living surface of a sample.
disinfection
What is the definition of a true pathogen?
does not require a weakened host to cause disease
Which of the following is the most general classification of an organism?
domain
What is the order of the taxonomic hierarchy from least specific to most specific?
domain, kingdom, phylum, class, order, family, genus, species
Used in conjunction with standard precautions, __________ are used to reduce the spread of an agent that is communicated through large moist respiratory droplets that do not remain suspended in the air, and therefore require closer contact for transmission
droplet precautions
Which of the following would not be important when evaluating measures of association?
duration of the disease
You are observing the cell shape of an unknown bacterial organism that you isolated from a patient, thus studying its _______.
phenotype
You observe that when you grow Serratia marcescens at human body temperature, the resulting bacterial colonies appear white. However, when you grow the same bacterium at room temperature, the colonies that grow are red. This difference in pigmentation is best described as a ____________.
phenotype difference
ATP is produced during a process called _______.
phosphorylation
An organism that harvests sunlight for energy and requires an external source of organic carbon in its metabolism is characterized as a _________.
photoheterotroph
Which of the following structures allow bacteria to transfer genetic information through conjugation?
pili
which body sites would least likely contain a biofilm
placenta
You have isolated a new eukaryotic organism which is unicellular and performs photosynthesis. The organism is most likely classified as a(n)
plant-like protista.
Which of the following groups of organisms does not have pathogenic members?
plants
Which of the following cell structures is found in all cells?
plasma membrane
Which of the following techniques is the best way to directly count viable cells?
plate counts
All the following apply to B cells except
play a critical role in both the cellular and humoral responses.
The thymus and bone marrow are examples of __________ lymphoid tissues and play a role in _________.
primary; maturation of leukocytes
Which of the following infectious agents are the most difficult to control with standard autoclaving methods?
prions
Which of the following is not a function of a molecular second line defense?
producing antibodies specific to the bacterial infection
Consider a genetic mutation which causes T helper cells to be unable to respond to stimulation by the cytokines which lead to TH2 differentiation. This mutation would cause a patient to be deficient in which activity?
production of antibodies
All of the following are examples of inclusion bodies in prokaryotic cells except __________.
endospores
Tachycardia and a drop in blood pressure are signs of _________ affecting the __________.
systemic anaphylaxis; cardiovascular system
Which of the following is the single most important procedure for a healthcare worker to prevent hospital-acquired infections (HAI)?
proper handwashing
Each element is identified by their atomic number, or number of _________.
protons
Listeria monocytogenes can grow slowly in your refrigerator, with its optimum temperature range between 30 to 37°C. This organism is characterized as a __________.
psychrotroph
Which of the following types of organisms is associated with foodborne illness?
psychrotrophs
In one variation of the influenza vaccine, hemagglutinin and neuraminidase are isolated from the viral particles and are then mixed with GEM particles, an adjuvant. This type of vaccine is known as an
purified, subunit vaccine
What triggers the release of cytokines, which signal the hypothalamus of the brain to raise the body's baseline temperature from 37°C to a higher temperature?
pyrogens
Which of the following are contributors to viral genome evolution?
quick replication time and the large number of virions released within a host
Zika virus is best described as a(n) _________ virus with a ________ genome.
enveloped, ssRNA+
Which of the following would be considered a zoonotic disease?
rabies
Your patient is suffering from Grave's disease. This type II hypersensitivity is caused by _________.
receptor overactivation
The 2014 outbreak of Ebola spurred the development of a new vaccine for this disease. The newly designed vaccines were ________.
recombinant vector vaccines
Which type of cellular transport uses transport proteins and moves substances from an area of high concentration to an area of low concentration?
facilitated diffusion
Which group of microbes prefers using oxygen but can survive without it?
facultative anaerobe
Although Staphylococcus aureus can grow at 7% NaCl, it grows best at NaCl levels less than 1%. This organism is a __________.
facultative halophile
A newly emerged infectious disease whose pathogen cause has not yet been identified is lethal in more than 90% of cases. Epidemiological evidence suggests that this pathogen is transmitted only through direct contact with the blood of ill or recently deceased patients. Patient blood and tissue samples would best be handled at BSL-2 until more information can be learned about the pathogen.
false
Which of the following factors impacts the signs, symptoms, and severity of an allergic response?
family history, route of exposure, and IgE production
When preparing growth media for Enterococcus durans, one must add amino acids, vitamins, and other growth factors in order for the organism to grow properly. This organism is said to be _________.
fastidious
Which of the following is not a cardinal sign of inflammation?
fever
Secondary lymphoid tissues
filter lymph and sample surrounding body sites for antigens which are brought into contact with the leukocytes that reside in secondary lymphoid tissues to stimulate an immune response.
Which of the following methods would be best for sterilizing a sample of a heat-sensitive solution?
filtration
How would Pseudomonas aeruginosa most likely adhere to the respiratory membrane of a patient in a ventilator?
fimbriae
Short, bristle-like structures that extrude from the surface of a prokaryotic cell are called
fimbriae.
Kupffer cells are examples of ________ that reside in the _________.
fixed macrophages; liver
Which does not describe eukaryotic flagella?
flagellin protein
Which of the following is not an approach to combat drug-resistant bacteria? flood a patient's system with healthy bacteria to quickly remove access to nutrients and starve the pathogen find multidrug approaches use lytic bacteriophages to specifically target pathogens pair a redesigned antimicrobial with inhibitors that block bacterial-resistance mechanisms identify new antimicrobials
flood a patient's system with healthy bacteria to quickly remove access to nutrients and starve the pathogen
Which of the following is not a domain?
fungi
The organism Candida albicans is classified as a __________ and grouped within the domain _________.
fungus; Eukarya
The sticky outer layer that can be found in both prokaryotic and eukaryotic cells is known as the _________.
glycocalyx
Which of the following pathways are operational in a cell growing via fermentation?
glycolysis
A colony (is a) _________.
grouping of cells that developed from a single parent cell
Which of the following regions in the human body supports the greatest variety of microbial species?
gut
Carriers of the sickle-cell gene
have a survival advantage in areas where malaria is common.
Which of the following pathogen agents is multicellular?
helminths
Bacteria used to make yogurt produce lactic acid only as a byproduct of fermentation. These organisms are said to use _________.
heterolactic fermentation
cytopathic effects induced by a virus include ______________
hijacking cellular machinery and disrupting normal host cell function
Which of the following hypersensitivities are T cell-mediated responses against self-antigens or otherwise harmless antigens?
type IV hypersensitivities
RNA is distinguished from DNA because only RNA:
typically exists as a single-stranded molecule.
The organism Mycobacterium tuberculosis makes mycolic acid, which is deposited in the bacterial cell wall and acts as a protective barrier for the cell and increases bacterial pathogenicity. Mycolic acid would be an example of a(n)_________.
wax
Your patient is suffering from severe diarrhea caused by a Clostridium difficile infection. Which of the following would be a special type of contact precaution to prevent spread of the organisms?
wear a barrier gown at all times
In what situation is hemolytic disease of the newborn a life and death situation?
when an RH- mom is pregnant for the second time with an RH+ fetus
When would a microbiologist want to use broth media?
when growing large batches of microbes
When would a microbiologist use thioglycolate?
when storing plates anaerobically
Toxemia is a condition
where a toxin has entered the bloodstream resulting in systemic effects.
What is the general classification used to categorize leukocytes?
whether or not leukocytes have granules in their cytoplasm that are visible when stained and then viewed by light microscopy
Which of the following infectious disease transmission modes is not correctly paired with an example?
windborne: cholera
Which of the following results would you expect from an interferon-gamma release assay from a patient suffering from an active tuberculosis infection?
you would expect T lymphocytes to release high levels of interferon gamma
Which of the following is the most common healthcare-acquired infection (HAIs)?
Clostridium difficile infections
Which of the following would not move freely across the cytoplasmic membrane?
Positively charged hydrogen ions
DSM: Smoking causes lung cancer. The validity of this statement was first verified by ________ studies.
cross-sectional
Smoking causes lung cancer. The validity of this statement was first verified by ________ studies.
cross-sectional
In a dehydration synthesis reaction, macromolecules are built when ________ is removed to form a covalent bond.
water
Which of the following examples of type II hypersensitivities are matched incorrectly with their mediated mechanism?
Goodpasture syndrome: noncytolytic
Which of the following is an example of a non-autoimmune type IV hypersensitivity?
Graft-versus-host disease
_________can exist as either a monomer or a snowflake-shaped pentamer and is central to _________.
IgM; agglutination and precipitation reactions
What is graft-versus-host disease?
Immune system cells in transplanted bone marrow attack the body of its new host.
In an experiment to calculate the decimal reduction time for an Escherichia coli culture, viable cells were exposed to a constant temperature of 80°C for a set amount of time. After exposure, the remaining number of surviving cells were counted. Based on Table 1, what is the decimal reduction time? Table 1. Decimal Reduction Time for E. coli Heated to 80°C Table 2 shows the decimal reduction time for Escherichia coli heated to 80℃. Initially, there are 100 cells present. After 1 minute, 80 cells are present. After 3 minutes, 50 cells are present. After 4 minutes, 42 cells are present. After 6.5 minutes, 26 cells are present. After 13 minutes, 10 cells are present. After 21 minutes, no cells remain.
13 minutes
You calculated the generation time of a strain of Pseudomonas aeruginosa as 40 minutes. How long would it take (in hours) for three generations to grow?
2 hours
Which of the following drugs demonstrates the most effective minimal inhibitory concentration? The figure shows a pallet with the size of 12 by 8 cells. There are 12 different drugs tested. The first row, row A shows all cells colored because there are no drugs in it. Drug concentration increases from the second to the eighth rows, from B to H. Drug 2 is colored in rows A through F. Drug 4 is colored in rows A through B. Drug 5 is colored in every row. Drug 6 is colored in rows A to G. Drug 9 is colored only in row A. 2 4 5 6 9
9
How are autoimmune disorders diagnosed?
A collection of tests and careful assessment of signs and symptoms are required.
What is the primary difference between a disinfectant and an antiseptic?
A disinfectant is used to decontaminate lifeless objects, whereas an antiseptic is applied to living tissue.
Cells can only contain which of the following types of genomes?
A double-stranded DNA genome
A major factor in the re-emergence of vaccine-preventable diseases in the early 21st centyry has been
A flawed research study incorrectly linking vaccination to autism was published in the late 1990s
Which of the following definitions correctly describes the CRISPR-Cas9 system?
A gene-editing tool that locates a specific DNA sequence and cuts it out so that a new sequence can be inserted.
Following a blood transfusion, your patient has disseminated intravascular coagulation and is experiencing hypotension (low blood pressure), tachycardia (increased heart rate), and low platelet count. During a blood typing analysis, you observed that this patient's blood had reacted with purified A antibody and Rh antibody, but not with purified B antibody. Based on this information, which of the following blood types was most likely given to the patient to result in this type II hypersensitivity?
AB+
A person with blood type A+ can safely donate to a person with blood type _____ and receive from a person with blood type _____.
AB+; O+
You would like to determine the blood type of your patient via an agglutination test. You add three drops of the patient's blood sample to a glass slide and add either anti-A, anti-B, or anti-Rh sera to each drop. You observe agglutination reactions in the samples to which you added the anti-A and anti-B sera. What is the blood type of your patient?
AB-
Which of the following statements about ATP is false?
ATP can be stored in large amounts in a cell.
You add 100 copies of a target gene to a thermocycler and set it to run through 30 cycles. How many copies can you expect once the procedure is finished?
About 1x1011
Why is it so difficult to kill acid-fast bacteria?
Acid-fast bacteria have mycolic acid in their cell walls, which limits drug entry.
Which of the following definitions is correctly matched?
Activation energy - the minimum amount of energy needed to get a reaction started
Which of the following types of transport would only be found in living cells?
Active transport
How does adaptive immunity differ from innate immunity?
Adaptive immunity generates immunological memory and is specific to a pathogen.
Adding salt or sugar to foods is a great way to preserve these foods for a longer period of time and prevent bacterial spoilage. Why?
Adding sugar or salt creates a hypertonic environment and water will be lost from bacterial cells, leading to plasmolysis.
What is an adjuvant?
Adjuvants are pharmacological additives that enhance the body's natural immune response to an antigen.
Which is the key difference between aerobic and anaerobic respiratory chains?
Aerobic respiratory chains always use oxygen as the final electron acceptor while anaerobic respiratory chains may use a variety of inorganic substances other than oxygen as the final electron acceptor.
Which of the following statements is true?
Agar is used as a solidifying agent for bacterial culture.
Alanine is a non-essential amino acid in humans. Based on this, select the true statement about alanine.
Alanine is made in human cells as the result of an amination reaction.
Which of the following is a correct statement about bacterial cell walls?
All bacterial cell walls contain peptidoglycan.
While performing an ELISA, a lab technician fails to rinse away unbound detection antibody from the wells before adding the substrate for the reporter enzyme. What is the likely outcome of this error?
All wells, including controls, will indicate a positive result
Which of the following is not associated with the DNA helix?
Amino acids
Which of the following was the first semisynthetic derivative of penicillin G? Ampicillin Amoxicillin Clarithromycin Rifampin
Ampicillin
Which of the following is the product of transcription?
An RNA sequence
Similar to the need for a primary activation signal to fully activate T helper cells, a primary activation signal is needed to activate B cells by T-dependent antigens. Which of the following serves as the primary activation signal?
An extracellular antigen binds to a B cell receptor.
Which of the following is an example of a direct contact transmission?
An individual contracts rabies after being bitten by a rabid raccoon.
You are working with two antibiotics. Antibiotic A has a half-life of six hours and antibiotic B has a half-life of three days. Which would be administered to the patient at more frequent intervals? Antibiotic A Both would be taken with the same frequency. Half-life is not a good indicator to determine how frequent an antibiotic would have to be administered. Antibiotic B
Antibiotic A
Which of the following molecules are only found as part of the humoral immune response?
Antibodies
Graves' disease is an example of which of the following type II hypersensitivity cytotoxic reactions?
Antibodies interact with a cell-surface receptor on self-cells causing the overactivation of the receptor.
__________, or amount of antibody present in the blood, is _________ during the secondary immune response.
Antibody titer; greater
Which description of antigenic drift and antigenic shift in the influenza virus is incorrectly matched?
Antigenic drift: Often involves reassortment of viral strains in an animal host followed by a "species jump" to humans.
In the Spring of 2009, a novel H1N1 virus emerged that had a new combination of genes from pigs, humans, and birds. As a result, the virus spread quickly, resulting in a swine flu pandemic. Which of the following concepts explains why the outbreak occurred?
Antigenic shift
_________ was the first scientist to observe bacteria under the microscope.
Antonie van Leewenhoeck
The three main pathways for complement activation all have the same general outcomes. Which of the following would not be an outcome?
Apoptosis
You identify a novel living organism that needs to be classified into one of the three domains of life. The organism has a cell wall containing pseudopeptidoglycan (pseudomurein), a plasma membrane, and a nucleoid region. Based on this information, which of the three domains would be the correct classification?
Archaea only
Which of the following would be an example of a chemical mutagen?
Arsenic
Which of the following statements best describes the hygiene hypothesis as it relates to allergies?
As a result of increased antibiotic usage and cleaner foods and beverages, our normal gut microbiota has shifted, resulting in increased hypersensitivities in developed countries.
Desensitization immunotherapy administers allergen in controlled amounts and stimulates T regulatory cell populations. Which of the following is not a correct statement about this therapy?
As a result of the controlled injection of the allergen, the number of IgE molecules is increased.
Choose the false statement about aseptic culturing techniques.
Aseptic technique is unnecessary in most labs because the majority of microbes are not pathogenic.
Bacteriophages use different mechanisms for host cell infection and viral replication. During the lytic replication pathway, bacteriophages infect the host bacterial cells and immediately build new virions. During which of the key steps is the genome packed into capsid and phage structures put together?
Assembly
___________ are transplants from self, like a self-skin graft from one part of the body to another location.
Autografts
according to the agglutination tests pictured below, what is the blood type of the sample being tested?
B
most hospitals and microbiology teaching labs maintain _________________ standards
BSL-2
Which biosafety level is incorrectly matched with its description?
BSL-2+: known animal pathogens which do not infect humans
a patient infected with a multi-drug resistant strain of Myocobacterium tuberculosis would be cared for in a _________________ facility.
BSL-3
Why did Alexander Fleming suspect he could get penicillin from a species of mold? Soldiers eating moldy bread were not suffering from wound infections. Wounds with superficial mold on the bandages were not becoming septic. Bacteria on culture plates were unable to grow near mold contamination. Soldiers drinking fermented alcohol were less likely to have bacterial infections. Patients infected with a fungus like, athlete's foot, were less likely to have bacterial infections.
Bacteria on culture plates were unable to grow near mold contamination.
Why can't prokaryotic species be defined as a group of similar organisms that could sexually reproduce together?
Bacteria reproduce asexually.
Which of the following statements is false about quorum sensing?
Bacteria that experience quorum sensing have a decreased chance of survival.
How does the cell wall of bacteria and archaea differ?
Bacteria use peptidoglycan.
Why is it entirely possible for a pathogen to appear susceptible in susceptibility testing and resistant in a real-life context? Bacterial levels and active drug concentrations vary from one tissue to another in an active infection. The ability of the pathogen to live as part of a biofilm and benefit from the protection of other bacteria does not exist in susceptibility tests. A real-life infection allows for the possibility of genetic crossover with different bacteria, whereas tests in the lab are focused on studying a single strain of bacteria. A person's liver may break down the drug before it even begins to benefit the patient. An active infection is more likely to mutate due to the larger population.
Bacterial levels and active drug concentrations vary from one tissue to another in an active infection.
Archaeal plasma membranes differ from bacterial plasma membranes. Which of the following is not a major structural difference?
Bacterial plasma membranes contain peptidoglycan while archaeal plasma membranes contain pseudomurein.
Which of the following methods is used to cultivate bacteriophages in the laboratory setting?
Bacteriophages are cultivated in bacteria in liquid broth or on solid medium.
A patient presents with symptoms of severe gastrointestinal distress. Bacterial and viral pathogens are ruled out. A protozoan which moves via hair-like appendages is observed upon microscopic examination of the patient's stool. The most likely cause of the infection is
Balantidium coli, a ciliated protozoan.
Which of the following restriction enzymes would recognize and cut the following DNA sequence? -TGGATCCA- -ACCTAGGT-
BamHI GATC CTAG
Which statement is not true about the virus capsid?
Because the capsid is not essential to the virus, it is not a useful target for antiviral drugs.
Benadryl (diphenhydramine) is an anti-histamine that can be used to treat atopic, allergic reactions. Which of the following statements best describes how this drug affects the inflammatory response?
Benadryl directly blocks the action of vasoactive molecules, leading to a decreased inflammatory response.
Which of the following is not a mechanism for horizontal gene transfer?
Binary fission
Which of the following types of cell division is found in prokaryotic cells?
Binary fission
Which of the following is a key distinguishing characteristic between budding and binary fission?
Binary fission results in daughter cells of equal size, whereas budding is an uneven division
Which of the following is an incorrect statement about biofilms?
Biofilms are composed of planktonic bacteria.
Which of the following is not one of the four cardinal signs of inflammation?
Bleeding
Which of the following is not a mechanism of an antiviral drug?
Blocking viral ribosomes
There are three common features shared by the innate and adaptive immune responses. Which of the following is not one of the three?
Both are only found in vertebrate animals.
Which of the following is a common feature between T and B cells?
Both produce memory cells after activation.
Which of the following is an incorrect statement about prokaryotes?
Both prokaryotic domains include known human pathogens.
Which statement is not true about eukaryotic ribosomes?
Bound ribosomes are always bound while free ribosomes are always free.
Which of the following statements about bright field microscopy are true?
Bright field microscopy is the simplest and most common form of microscopy.
Which of the following is a molecule?
C6H12O6
Which of the following might be used by a chemoorganoheterotroph for energy?
C6H12O6
Which of the following is (are) organic? To be marked correct, you'll need to select all true statements, as there may be more than one correct answer.
C6H12O6 CH4
Which of the following is an organic molecule?
CH4
DSM: Which of the following is the most common healthcare-acquired infection (HAIs)?
Clostridium difficile infections
DSM: Which of the following are examples of endogenous sources of transmission?
Candida albicans (pathogenic strain of yeast)
Which of the following are examples of endogenous sources of transmission?
Candida albicans (pathogenic strain of yeast)
Which of the following cell surface structures may initiate B cells by T-independent antigens?
Capsules
Which of the biomolecules is incorrectly matched with its building block?
Carbohydrate: Polysaccharide
When we say that catabolic and anabolic reactions are coupled, what does that really mean?
Catabolic reactions provide energy and smaller molecules required by anabolic reactions.
Which of the following is not a factor that influences enzyme activity?
Catalysts
____________ are organic or inorganic substances that increase the rate of a reaction but are not used up in the reaction.
Catalysts
Which of the following is not one of the hallmark signs of primary immunodeficiencies?
Caused by common infectious agents
__________ are small proteins that help fold larger proteins.
Chaperones
MCP-1 is a cytokine which induces monocytes migration and infiltration. This protein is an example of which type of cytokine?
Chemokine
_________ is to fungal cell walls as _________ is to bacterial cell walls.
Chitin; peptidoglycan
What molecule is used to capture light energy?
Chlorophyll
Many strains of E. coli are able to grow on minimal media which consists only of a single sugar, usually glucose, and inorganic salts to provide nitrogen, sulfur, phosphorous and trace nutrients. What does this tell you about E. coli's biosynthetic capabilities?
E. coli can funnel intermediates from glycolysis, the intermediate step, and the Krebs cycle to synthesize amino acids, fatty acids, glycerol, and nucleotides
___________ are formed when ionic compounds dissolve in solution and have a role in regulating blood volume.
Electrolytes
During which step of cellular respiration is most ATP produced?
Electron transport chain
Which of the following processes occurs in the plasma membrane of a prokaryotic cell?
Electron transport chain
Your patient is experiencing an acute case of salmonellosis, a bacterial gastrointestinal infection. Which of the following would you expect to see on a differential white blood cell count?
Elevated neutrophil count
Which of the following eukaryotic organelles plays an essential role in protein and lipid production in the cell?
Endoplasmic reticulum
Which of the following is true about endospores?
Endospores are highly resistant to environmental stress.
Which of the following statements is incorrect about endospores?
Endospores are reproductive structures.
Part complete Why do all enzymatic reactions need activation energy?
Energy is required to disrupt a substrate's stable electron configuration.
What is the relationship between the ATP-ADP cycle and catabolic and anabolic reactions?
Energy released from catabolic reactions is used to recharge ADP back to ATP. Then the energy needed for anabolic reactions is released by breaking ATP down to ADP.
Your patient has severe diarrhea and is passing mucus and blood. Stool samples that were obtained and checked under the microscope revealed cysts. His patient history also indicates that he recently traveled to southeast Asia. What is he likely infected with?
Entamoeba histolytica
Why are enzymes important to biological systems?
Enzymes decrease the amount of activation energy required for chemical reactions to occur.
Which of the following statements correctly describes enzymes?
Enzymes increase the reaction rate.
What is meant by the statement "Enzymes are biological catalysts"?
Enzymes speed up the chemical reactions in living cells.
Which of the following is one way that enzymes decrease activation energy?
Enzymes stabilize the reaction's transition state.
You would like to show the presence of Gram-negative lactose fermenters in your unknown pure culture. Which of the following media would be most appropriate?
Eosine methylene blue (EMB) agar
Your patient is suffering from a parasitic infection. Which of the following cells would most likely be elevated?
Eosinophils
Ethylene glycol is an ingredient in antifreeze. If antifreeze is swallowed, the enzyme alcohol dehydrogenase binds to the ethylene glycol and converts it to toxic oxalic and glycolyic acid. One of the treatments for ethylene glycol poisoning is the administration of the enzyme's natural substrate, ethanol. Based on this information, what is the best way to describe how ethanol protects against ethylene glycol poisoning?
Ethanol competes with ethylene glycol to limit oxalic and glycolyic acid formation
Which of the following chemicals is applied as a gas to sterilize equipment and disinfect surfaces?
Ethylene oxide
Your patient is receiving a spinal fusion to correct a skeletal defect. Which of the following germicides is recommended to sterilize the bone used for the transplantation?
Ethylene oxide
Which of the following statements is false?
Eukaryotes have a much simpler genetic makeup than prokaryotic cells.
Your patient has a stubborn case of athlete's foot. After treatment with an antifungal agent, you observe fungal cell lysis as a result of improperly built plasma membranes. Which of the following antifungal drugs was most likely used during treatment? Flucytosine Amphotericin B Capsofungin acetate Fluconazole
Fluconazole
How does immunofluorescence microscopy detect rabies in the brain tissue of an infected animal?
Fluorescent-tagged antibodies bind to rabies antigen in the tissue and are visible in a specialized microscope
Which of the following is an example of dysbiosis?
Following extended use of amoxicillin, your patient develops oral thrush as a result of the overgrowth of Candida albicans.
Which of the following is a true statement about the tuberculin skin test?
For the test, PPD is injected into the skin of the forearm.
Which of the following "germicides" should only be applied as a disinfectant?
Formaldehyde
You have isolated a new organism which has eukaryotic cells, is multicellular, grows as hyphae, does not perform photosynthesis, and has a cell wall. This organism most likely belongs to which kingdom?
Fungi
You are observing an unknown, unicellular organism with a high-resolution and magnification microscope. You are noting the presence of various membrane-bound organelles. Which of the following types of cells are you likely working with?
Fungus
Which of the following is a common healthcare-acquired infection?
Gastrointestinal infection caused by Clostridium difficile
Which of the following statements describes the purpose of gene shuffling?
Gene shuffling generates an enormous repertoire of antigen receptors during lymphocyte development.
Which of the following is characterized as a Mastigophora, or "flagellated protozoan"?
Giardia intestinalis
DSM: Which of the following diseases is noncommunicable, meaning that it is not spread from person to person?
Giardiasis
Which of the following diseases is noncommunicable, meaning that it is not spread from person to person?
Giardiasis
Which of the following would not be a building block of a nucelotide?
Glucose molecule
Which of the following processes are likely utilized by an obligate anaerobe that generates energy through respiration and is not capable of fermentation?
Glycolysis, Krebs cycle, electron transport chain
How do glycopeptide drugs differ from beta-lactam drugs? Glycopeptide drugs are easily absorbed across the intestines and therefore commonly used as oral preparations against systemic infections. Glycopeptide drugs specifically target Gram-negative bacteria. Glycopeptide drugs do not have a beta-lactam ring, so they are not susceptible to beta-lactamases. Glycopeptide drugs are often found to be ineffective due to antibiotic-resistance. Glycopeptide drugs are broad-spectrum drugs, unlike beta-lactamases which are narrow-spectrum drugs.
Glycopeptide drugs do not have a beta-lactam ring, so they are not susceptible to beta-lactamases.
The _______ resembles a series of flat sacs called cisternae. This organelle modifies, builds, sorts, and distributes products to the cell membrane to be secreted.
Golgi apparatus
While many areas on and in the human body contain a variety of microbes, there are "microbe-free zones." Which of the following would not typically be a microbe-free zone?
Human gut
Which of the following oncogenic viruses may integrate into the host genome?
Human papilloma viruses (HPVs)
Which of the following statements describes why sulfa drugs do not interfere with mammalian biological pathways? Humans do not require folic acid (the target of sulfa drugs) for metabolic processes. Sulfa drugs are rapidly inactivated once inside the human body. Humans do not independently synthesize folic acid (the target of sulfa drugs), but acquire it from their diet. Prokaryotic ribosomes, the target of sulfa drugs, are smaller in comparison to eukaryotic ribosomes.
Humans do not independently synthesize folic acid (the target of sulfa drugs), but acquire it from their diet.
Which of the following can be a potential disease reservoir for a pathogen which infects humans?
Humans, non-human animals, inanimate objects, or environmental niches can all serve as reservoirs for a pathogen which infects humans.
Which of the following enzymes breaks down the "glue" that holds cells together?
Hyaluronidase
Which of the following would be the weakest bond?
Hydrogen bond
____________ do not bind atoms into molecules. Instead, they are non-covalent electrostatic attractions between two or more molecules or within a single large molecule.
Hydrogen bonds
Which of the following statements about hydrogen bonds is incorrect?
Hydrogen bonds are a covalent electrostatic attraction between two or more molecules.
Which of the following is not considered a chemical pathway?
Hydrolytic pathway
Advantages of the interferon-gamma release assay(IGRA) over the traditional TB skin test include all of the following except.
IGRA only detects active TB infections
A young patient who underwent surgical placement of depth electrodes for epilepsy treatment contracted a prion disease. Cortical electrode probes are known to be reused in patients. Based on this information, which of the following prion diseases did the young patient most likely contract?
Iatrogenic Creutzfeldt-Jakob Disease
Which of the following terms is used to describe the shape of a virus?
Icosahedral
Which of the following statements about plasmids is false?
If present, plasmids are always essential to cell survival.
The antibody found in breastmilk and coating mucous membranes is
IgA.
Your patient has an anaphylactic response to bee venom. Which of the following classes of antibodies would you expect to be elevated in the patient's serum, based on this hypersensitivity?
IgE
In type I hypersensitivities, allergen exposure triggers the immune system to produce ________. This is called the _________.
IgE; sensitizing exposure
Which of the following antibodies can cross the placenta and is the most abundant of all antibodies?
IgG
The most abundant antibody class in the body, found in all body fluids, is
IgG.
Generally, the first antibody class made upon a primary antigen exposure is
IgM
Which of the following statements is true concerning the alternative complement cascade?
In the alternative complement cascade, complement proteins directly interact with the invading agent.
According to the figure, when were measles the most prevalent in the US?
In the late 50s
DSM: Which of the following is not part of the epidemiological triangle?
Incidence rate
Which of the following is an example of phage conversion?
Infection of Streptococcus pyogenes with T12 phage enables the bacteria to produce erythrogenic toxins, allowing it to cause scarlet fever.
Which of the following terms is correctly matched with its description?
Insertion mutations: Occur when a cell adds one or more nucleotides to its genome sequence.
_________ play a role in hematopoiesis.
Interleukins
What is the difference between an intolerance and an allergy?
Intolerances tend to have a delayed onset of symptoms, while allergic reactions occur rapidly.
Your patient is suffering from a systemic, bacterial infection. Which of the following would be the best way to adminster an antimicrobial drug for treatment of the infection? Subcutaneously Intravenously Intramuscularly Orally
Intravenously
The correct order of steps to follow when using recombinant DNA technology to produce a protein for pharmacological use is
Isolate the desire gene- insert the gene into an expression vector- transform host cells with the expression vector- grow the transformed cells into suitable quantities- puify the expressed protein
_____________ are atoms with the same number of protons but a different number of neutrons.
Isotopes
Which statement is not true about the pentose phosphate pathway?
It allows cellular respiration to occur without the need for oxygen.
You are programming a thermocycler and are setting temperature of the second step in your protocol to 62°C. What is happening during this step?
It allows the primers to anneal.
Which of the following statements about electron microscopy is false?
It has a maximum magnification of 1000x
What is the function of a carboxysome?
It houses carbon-fixation enzymes.
Select the true statement(s) about bright field microscopy. To be marked correct, you'll need to select all true statements, as there may be more than one correct answer.
It illuminates the specimen using visible light. Bright field microscopy is the most simple and common form of microscopy. A dark image is contrasted on a bright background.
Which of the following is an incorrect statement about aseptic technique?
It is a sterile technique
Choose the false statement about the eukaryotic cytoskeleton.
It is an extension of the glycocalyx.
Genome maps reveal valuable information about an organism. Which of the following would it not be helpful with?
It is not a useful tool for investigating differences between healthy cells and diseased ones, such as cancer cells.
DSM: In many parts of the US, West Nile infections increase during the summer months. What is the reason?
It is transmitted by mosquitos, which are more prevalent during the summer months.
In many parts of the US, West Nile infections increase during the summer months. What is the reason?
It is transmitted by mosquitos, which are more prevalent during the summer months.
Which of the following best describes substrate level phosphorylation?
It occurs when an enzyme transfers a phosphoryl group from a donor substrate directly to ADP to make ATP.
Which of the following statements about the lagging strand is false?
It uses only one molecule of DNA polymerase I.
Which of the following scientists investigated processes for aseptic surgery?
Joseph Lister
In the ___________, antibiotic paper disks are added to a solid medium inoculated with a standard amount of a pure bacterial culture to test whether the organism is sensitive, intermediate, or resistant to the drug. E-test broth dilution test Kirby-Bauer test antimicrobial response test
Kirby-Bauer test
Your laboratory is working with Clostridium tetani, the etiological agent for tetanus. Which of the following minimum personal protective equipment (PPE) are relevant for this type of pathogen?
Lab coats, gloves, and safety goggles or a face shield (if there is splash risk) should be worn.
Which of the following conditions would allow for the active transcription of the lac operon?
Lactose present, glucose absent
Which of the following scenarios provides an example of isotype switching?
Late in an infection with Influenza virus, a given plasma cell stops production of IgM and begins producing IgG.
DSM: Eradication of an infectious disease means that there are no longer any cases of it anywhere in the world. Which of the following types of infectious diseases would be the most difficult to eradicate?
Latent infectious diseases
Which type of method is used to determine if a prior exposure to a virus occurred?
Latex agglutination test
Which of the following is one of the categories of the second-line defenses?
Leukocytes
Which of the following is not one of the three main ways microbes evade antimicrobial drugs? Alter the drug's target Limit production of peptidoglycan Pump drugs out Inactivate drugs
Limit production of peptidoglycan
Which of the following statements incorrectly describes viral spikes?
Lipid-based spikes make up the envelope that surrounds the capsid.
___________ contain pathogens that have been altered so that they do not cause disease (are not pathogenic), but are still infectious.
Live attenuated vaccines
The bactericidal antibiotic penicillin kills bacterial cells by preventing peptidoglycan (cell wall) biosynthesis. Which of the following phases of the bacterial growth curve would you expect penicillin to be most active against?
Logarithmic phase
________ showed that biogenesis is responsible for the propagation of life.
Louis Pasteur
Cellular and humoral responses both progress through four main stages. What is the second stage?
Lymphocyte activation
Which of the following vesicles contain a wide variety of hydrolytic enzymes that break down substances engulfed by the cell during phagocytosis?
Lysosomes
_____________ is a type of sexual reproduction that occurs in eukaryotes and results in four genetically unique haploid daughter cells.
Meiosis
Which of the following antimicrobial drugs can be inactivated by beta-lactamase? Chloramphenicol Meropenem Streptomycin Clavulanate
Meropenem
Helicobacter pylori is a bacterial pathogen known to cause duodenal and gastric ulcers in humans. One of the cornerstones for treatment of H. pylori is a proton pump inhibitor. Which of the following terms best describes H. pylori?
Mesophilic acidophile
The mRNA template contains the sequence AUGGCUAGGUGA. Which would be the corresponding correct amino acid sequence?
Methionine - Alanine - Arginine - Stop
Which of the following fibers are found as part of the eukaryotic cytoskeleton?
Microtubules, intermediate filaments, and microfilaments
If a wild-type DNA sequence reads AAA ACG CCG AGG, what type of mutation would change it to AAA ACC CCG AGG?
Missense
Which of the following provides supporting evidence that mitochondria and chloroplasts may have once been free-living prokaryotes?
Mitochondria and chloroplasts contain 70S ribosomes.
Eukaryotic cells are not found in which of the following kingdoms?
Monera
_________ are only weakly responsive to traditional desensitization therapies.
Most food allergies
Which of the following is an incorrect statement about pH?
Most microbes grow best at a pH between 5 and 6
Which of the following statements about mutations is false?
Multicellular organisms evolve faster than unicellular organisms.
Which of the following is an example of a reemerging disease?
Mumps, once nearly eliminated, has increased in prevalence due to under-vaccination in industrialized countries.
Which of the following is not a mode through which microbes may share resistance genes? Transformation Mutations Conjugation Transduction
Mutations
Which of the following cell structures are only found in eukaryotic cells?
Nucleus
Why are most prokaryotic cells small?
Nutrient diffusion is most efficient for smaller cells.
You are working in the ER and have a patient that needs a blood transfusion. Without knowing his blood type, which of the following blood types would you be able to safely provide?
O-
Which of the following is a valid difference between the leading and lagging strands in DNA replication?
On the leading strand, only a single RNA primer is needed to initiate continuous DNA synthesis.
Which of the following statements concerning T cell self-tolerance screening is true?
Once T cells pass the self-tolerance screening, they migrate to lymphoid tissues.
Using the Periodic Table of Elements, select all of the true statements about carbon. To be marked correct, you'll need to select all true statements, as there may be more than one correct answer.
One carbon atom contains 6 protons and 6 neutrons. Carbon's atomic number is 6.
An individual uses an in-home test kit one week after engaging in high-risk behavior for HIV infection. The test kit uses a saliva sample that is mailed to a lab where an agglutination test to detected HIV antibodies is run. The results come back negative for HIV. What should the patient consider regarding these test results?
One week may not be enough time for HIV antibodies to be detected.
Post-transcriptional regulation allows cells to control gene expression by regulating how often mRNA is translated into protein. Which of the following is not an example of post-transcriptional regulation?
Operons
Which of the following infectious agents usually requires an immune-compromised person to establish an infection?
Opportunistic pathogen
Candida albicans is part of our normal oral flora. Under certain conditions, it can overgrow, leading to oral thrush. Typically, infections are seen in individuals who are immunocompromised, such as newborns or individuals who may have recently taken antibacterial medications. This type of pathogen is classified as which of the following?
Opportunistic, endogenous pathogen
Which of the following routes of drug administration is ideal? Intravenously Intramuscularly Orally Subcutaneously
Orally
Which of the following statements would be most correct about the organisms growing in tubes A and B containing phenol red glucose broth?
Organism A fermented glucose, producing acid and gas, while organism B did not ferment glucose.
You are working on characterizing the metabolism on an unknown organism. You find that the organism is a strictly fermentative organism. Which of the following mechanisms is likely absent?
Oxidative phosphorylation
A nurse experienced an accidental needle stick while treating a patient who has hepatitis C. The seroconversion window for hepatitis C is approximately 6-8 weeks. Given this information, which of the following viral detection methods would be most appropriate for detecting a hepatitis C infection in the nurse one week following the needle stick?
PCR-based detection of hepatitis C RNA
The 1918 influenza virus killed more individuals worldwide than World War One. It is estimated that between twenty and forty percent of the world's population across continents had become infected with the virus, leading to 50 million deaths. The 1918 influenza would best be described as which of the following?
Pandemic
DSM: _________ is the ability of an infectious agent to cause disease.
Pathogenicity
_________ is the ability of an infectious agent to cause disease.
Pathogenicity
Which type of bond links amino acids together to form a protein's primary structure?
Peptide bonds
Which of the following is not a key antibody function?
Phagocytosis
What is the key difference between photoheterotrophs and photoautotrophs?
Photoheterotrophs use organic compounds as their carbon source; photoautotrophs use carbon dioxide as their carbon source.
In an environment with sunlight and an abundance of inorganic compounds, which group of organisms are most likely to thrive?
Photolithoautotrophs
DSM: Which of the following groups of organisms does not have pathogenic members?
Plants
Which technique would prove that a patient was exposed to a certain virus even if it is no longer in their system?
Plaque reduction neutralization test
Which of the following cell structures is found in all cells?
Plasma membrane
Which of the following structures is not found in a Gram-negative cell wall?
Plasma membrane
Which of the followng structures is found in all cells?
Plasma membrane
Choose the statement which best defines a pleomorphic organism.
Pleomorphic organisms can take on different forms, which enhances their survival and transmission to a human host.
Which of the following is a correct statement about polar substances?
Polar, or hydrophilic, substances readily dissolve in water
You are comparing the size of different viruses. You are specifically interested in the size of the following viruses: Ebola virus, Poliovirus, Rhinivirus, and Pithovirus. Which of these viruses would be the smallest, and which the largest?
Poliovirus is the smallest; Pithovirus the largest.
Which of the following enzymes is incorrectly matched with its function?
Polymerase I - copies DNA on the leading and lagging strands.
In which of the following scenarios would you expect lysozyme to be an effective chemical barrier?
Preventing the entry of Haemophilus aegyptius, a Gram-negative bacterial pathogen, into the conjunctiva
Which of the following acellular agents do not have any genetic material and therefore do not replicate?
Prions
Choose the features of the prokaryotic ribosome that support the endosymbiotic theory.
Prokaryotes have a ribosome with a 70S sedimentation rate.
Select the false statement about the differences between eukaryotes and prokaryotes.
Prokaryotic cells can exhibit both asexual and sexual reproduction, whereas eukaryotes only carry out asexual reproduction.
Which of the following is true about ribosomes?
Prokaryotic ribosomes have a lower overall mass and diameter than eukaryotic ribosomes.
DSM: Which of the following is the single most important procedure for a healthcare worker to prevent hospital-acquired infections (HAI)?
Proper handwashing
Part complete Which particle is described incorrectly?
Proton: Found in shells orbiting the nucleus
Which of the following microbial temperature classifications is improperly matched with its potential growth environment?
Psychrotroph - arctic lake sediment
Choose the false statement(s) about acids and bases. To be marked correct, you'll need to select all false statements, as there may be more than one correct answer.
Pure water has more H+ ions than OH- ions. If an acid is added to an acidic solution, the pH will increase.
Which of the following types of organisms uses hydrogen sulfide for reducing power?
Purple sulfur bacteria
Praziquantel is an antihelmnithic drug that works through which of the following mechanisms of action? Pyrantel interferes with metabolism by uncoupling oxidative phosphorylation. Pyrantel blocks anaerobic energy metabolism. Pyrantel interferes with glucose uptake by targeting microtubules. Pyrantel paralyzes the parasite, allowing it to detach from host tissues.
Pyrantel paralyzes the parasite, allowing it to detach from host tissues.
Which of the following is a drug used to treat malaria and gives tonic water its characteristic bitter taste? Chloroquine Quinolone Fluoroquinolone Quinine
Quinine
The picture shows the amino acid tryptophan. The highlighted group in green is also known as the _________.
R group
Which of the following vaccines is administered orally?
Rotavirus vaccine
Which grouping of parasitic helminths includes hookworms?
Roundworms
You wish to set up a DNA microarray to study which genes are implicated in breast cancer. You fluorescently label normal breast tissue with a green fluorophore and tumor breast tissue with a red fluorophore. You see that your gene labeled SASH1 fluoresced green while your gene labeled HER2 fluresced red. Taken together, these results indicate that:
SASH1 is underexpressed in breast cancer patients, whereas HER2 is overexpressed in breast cancer patients
Which of the following is incorrectly matched?
Salt: Formed by the combination of hydrogen ions (H+) and hydroxide ions (OH-)
Which biological molecule is shown in the picture? The picture shows one of the four main classes of biologically important biomolecules. It contains a glycerol head and a fatty acid tail.
Saturated fatty acid
Which type of vesicle/vacuole is incorrectly matched with its description?
Secretory vesicle: Replenishes the lipid bilayer and deliver proteins for incorporation into the membrane
Which of the following vesicles is incorrectly matched with its function?
Secretory vesicles: ferry digestive enzymes to the endoplasmic reticulum
You suspect that your patient has a urinary tract infection caused by Proteus vulgaris, a motile bacterium with peritrichous flagella. Which of the following physical states of media is best for observing motility of this pathogen once isolated?
Semisolid deep
Which of the following is an organic molecule made by bacteria that sequesters iron from host iron-binding proteins?
Siderophore
How is simple diffusion different from other types of passive transport?
Simple diffusion does not require a permease.
Which of the following is the most important physical barrier of the first line of defense?
Skin
Which of the following diseases was eradicated after a successful vaccination program?
Smallpox
A catalase test would be helpful to distiguish which of the following organisms?
Staphylococcus and Streptococcus species
Which of the following is not an example of intrinsic resistance of a bacterium to an antimicrobial drug? Mycobacterium tuberculosis have a waxy cell wall Mycoplasma pneumoniae lacking a cell wall Clostridium difficile form endospores Staphylococcus aureus (VRSA) strains with altered cell wall-building enzymes
Staphylococcus aureus (VRSA) strains with altered cell wall-building enzymes
Upon performing a Kirby-Bauer disc diffusion test using Staphylococcus aureus, you observe no zone of inhibition with penicillin and a 15mm zone of inhibition with vancomycin. Based on these observation, which of the following conclusions is valid? Staphylococcus aureus is resistant to penicillin but may or may not be sensitive to vancomycin. Staphylococcus aureus is resistant to both vancomycin and penicillin. . Staphylococcus aureus is resistant to penicillin and sensitive to vancomycin. Penicillin is bactericidal toward Staphylococcus aureus, and vancomycin is bacteriostatic toward S. aureus.
Staphylococcus aureus is resistant to penicillin and sensitive to vancomycin.
Which of the following virulence factors would be found in Staphylococcus aureus?
Staphylokinase
Which of the following would not be a component of an operon?
Start codon
We explore questions about the origins of disease and treatments through the scientific method. Which of the following would be the most likely order to apply the scientific method?
State question - Formulate Hypothesis - Design Experiment - Collect Data - Draw Conclusions
Which of the following microorganisms use M protein to avoid destruction of a phagocyte?
Streptococcus pyogenes
How does the antibiotic sulfanilamide inhibit bacterial growth?
Sulfanilamide is a competitive inhibitor that competes with para-aminobenzoic acid, thus affecting folic acid synthesis of a bacterial cell.
___________include a variety of bacterial toxins (e.g. staphylococcal enterotoxins and staphylococcal toxic shock toxin) and are especially potent T helper cell activators.
Superantigens
Which would be the most appropriate tools to collect samples from a patient infected with Clamydia trachomatis?
Swab with a plastic or wire shaft and a non-cotton tip
Which aspect of the polymerase chain reaction is mismated with its description?
Template DNA: the DNA to be copied; must be present at a high concentration for the procedure to work
A 6-year-old patient is suffering from Lyme disease and antimicrobials are prescribed to treat the infection. Which of the following antimicrobial compounds would not be prescribed? Vancomycin Penicillin Tetracycline Bacitracin
Tetracycline
Choose the true statement about the Domain Bacteria.
The Domain Bacteria is made up of prokaryotes and likely originated 3.8 billion years ago.
Unlike the Kirby-Bauer disc diffusion test, the E-test can provide which of the following information? The E-test provides the minimum bactericidal concentration. The E-test can provide the minimum inhibitory concentration for a given drug. The E-test can determine the half-life of a given drug inside of the human body. The E-test can determine whether an antimicrobial drug is bactericidal or bacteriostatic.
The E-test can provide the minimum inhibitory concentration for a given drug.
Why is there a need to be vaccinated with a new flu shot every year?
The RNA genome of influenza mutates frequently, causing minor changes. This is referred to as antigenic drift.
The interferon-gamma release assay for tuberculosis infection works because
The T cells of an infected person release more interferon-gamma than that of a non-infected person
What is a drawback of live attenuated vaccines?
The agents present in this type of vaccine could cause disease in an immune-compromised host.
Which of the following is an example of intrinsic resistance? A strain of previously non-drug-resistant Escherichia coli receives an amoxicillin resistance gene during conjugation with a drug-resistant strain of Escherichia coli. The bacterium Staphylococcus aureus acquires a mutation in the ribosomal binding site for the antimicrobial drug tetracycline. A strain of previously non drug--resistant Bacillus subtilis acquires a ciprofloxacin resistance gene as a result of genetic transformation with a plasmid containing the drug-resistance gene. The bacterium Bacillus cereus produces endospores during environmentally harsh conditions, enabling it to survive cooking processes.
The bacterium Bacillus cereus produces endospores during environmentally harsh conditions, enabling it to survive cooking processes.
What will happen to a cell that is placed in a solution containing a high concentration of sugar, a molecule that cannot pass across the cell membrane?
The cell will lose its interior water, causing it to shrivel up and possibly die.
Considering the process of osmosis, what will occur if a bacterial cell is put into a hypotonic solution?
The cell will take on water and may lyse if its cell wall is damaged.
Which of the following statements is true concerning cellular immunity?
The cellular branch of adaptive immunity is mainly organized by T helper cells and carried out by T cytotoxic cells.
A potential antimicrobial drug is tested and found to strip away the capsules made by certain pathogenic bacteria. How would this drug affect the bacteria's ability to cause disease?
The phagocytes would be better able to ingest the bacteria.
Which of the following is a trait unique to photosynthetic eukaryotes?
The presence of chloroplasts
Why is no energy required in passive transport?
The concentration gradient drives the movement.
The technique of vaccination as developed by jenner was an improvement over variolation because
The cowpox virus used by jenner was not fatal to humans but provided protection against smallpox
Which of the following statements correctly describes what happens during chemiosmosis?
The energy of protons flowing through the ATP synthase enzyme powers the recharge of ADP to ATP.
Choose the true statement about protein synthesis.
The first amino acid in a eukaryotic protein sequence is methionine, whereas the first amino acid in a prokaryotic protein sequence is formyl methionine.
Choose the true statement about the genetic code
The genetic code is redundant, with multiple codons specifying a single amino acid.
Which of the following provides the best definition of the term reservoir?
The habitat where a pathogen is typically found.
The generation time for Escherichia coli inside of the human intestinal tract has been estimated at 12 hours. However, when grown in Luria Bertani medium as a pure culture under standard laboratory conditions, the generation time for E. coli is 20 minutes. Which of the following accounts for this discrepancy in generation time?
The human intestinal tract contains other microbes, which compete for limited nutrients.
Which of the following is an example of a measure of association?
The infant mortality rate in the United States due to consumption of unpasteurized honey
Which of the following is a key difference between lytic and lysogenic bacteriophage replication cycles?
The lytic replication cycle ends with host cell lysis and release of newly formed bacteriophage particles, whereas lysogenic replication leads to prophage formation.
Choose the false statement about the cell's nucleus.
The nucleus contains a region called the nucleolus, where DNA is copied.
Which of the following descriptions provides the best definition for mortality rate?
The number of deaths during a specific time period
Penicillin is an antibiotic that interferes with peptidoglycan construction in cell walls. Why would this antibiotic not be a good treatment option for patients infected with Mycoplasma pneumonia?
The organism Mycoplasma pneumonia does not have a cell wall.
Which of the following is not one of the four postulates of disease developed by Koch?
The organism should be present in mixed culture.
Your patient is born without a thymus. This inherited, chromosomal deletion would affect the patient in which of the following ways?
The patient would not produce mature T lymphocytes.
Which of the following is a correct statement about herd immunity?
The percentage of a population that must be vaccinated for herd immunity to be effective varies based on the pathogen.
One ml of a liquid suspension of bacteriophage is mixed with its host bacteria and plated. After incubation, the plate is completely clear. What is the probable explanation?
The phage concentration was so high that all the host bacterial cells were killed.
Which of the following statements about the primosome is false?
The primosome includes RNA polymerase to build the protein.
Which of the following statements concerning the secondary response is true?
The secondary response results in production of antibodies with a higher affinity for the antigen.
Chloroflexus aurantiacus is a photoautotrophic bacterium that grows in hot springs. Which of the following serves as an energy source for C. aurantiacus?
The sun
Which of the following statements is incorrect about interferon gamma release assays (IGRAs) used to detect TB in vaccinated populations (vaccinated with BCG vaccine)?
The test is very sensitive and can determine if a patient with a positive IGRA has an active versus latent infection.
You inoculated a pure culture of unknown bacteria into a tube containing thioglycollate medium to study their metabolic relationship with oxygen. The culture was incubated for an appropriate length of time at the optimal growth temperature of the organism. When you examined the culture, you observed that although the organism grew throughout the medium, the growth was denser at the surface. What would you conclude about the oxygen requirements for this unknown species?
The unknown is a facultative anaerobe.
Which of the following is an example of bioremediation?
The use of Marinobacter species to degrade oil
You observe that a novel virus penetrates the host cell through membrane fusion. Which of the following statements must also be true regarding this virus and its replicative cycle?
The virus releases from host cells by budding.
How is Streptococcus pneumoniae able to avoid destruction by a phagocyte?
Their capsules make them "slippery" to phagocytes.
What is the definition of eradication of an infectious disease?
There are no longer any cases of the microbe anywhere in the world for three consecutive years.
Why are Koch's postulates important to microbiology?
They allowed us to identify the causative pathogens of many infectious diseases
Which of the following is not a feature of eukaryotic flagella?
They are built from flagellin proteins.
Which of the following is true about inorganic cofactors?
They are nonprotein agents.
How do fibrinolysins enhance a pathogen's virulence?
They break down fibrin proteins that are involved in clot formation, allowing the cells to penetrate deep into damaged skin.
Which of the following statements is true about sulfa drugs? They chemically resemble PABA, the natrual substrate of a bacterial enzyme in the pathway that build folic acid. They are bacteriocidal. They have a narrow spectrum of action. They can only be administered orally.
They chemically resemble PABA, the natrual substrate of a bacterial enzyme in the pathway that build folic acid.
Why might broad spectrum antimicrobials be initially used when treating a patient? The physician has never encountered that pathogen before. An initial round of broad spectrum antimicrobials increases the efficiency of narrow spectrum antimicrobials. They may initially be used to protect the patient since it can take several days to make a definitive bacterial identification. It's best to start with broad spectrum antimicrobials until patient records are available that show if the patient has any antimicrobial allergies. They are cheaper to use.
They may initially be used to protect the patient since it can take several days to make a definitive bacterial identification.
Choose the true statement about pre-transcriptional regulation.
This form of regulation controls when and how often RNA is produced from a DNA template.
Genetic mutations in the CD8a gene often result in a CD8 T cell deficiency. Which of the following scenarios would be most likely to occur in a patient with several CD8a gene mutations?
This patient would be less able to respond to certain viral invaders, such as Epstein Barr Virus.
Which of the following is not a secondary lymphoid tissue?
Thymus
Which of the following is not a main goal of inflammation?
To allow for the complement cascade to become activated
Which of the following statements best describes the goal of the first line of immune defense?
To prevent pathogen entry
What is the role of light energy in photosynthesis?
To produce a proton gradient to make ATP
Which of the following microscopy terms is correctly matched with its definition?
Total magnification - the magnification resulting from multiplying the magnification of the ocular and objective lenses
Which term is incorrectly matched with the provided definition?
Transduction - introduction of new genetic material into a viral cell by a bacterial species
How does transformation differ from conjugation?
Transformation takes up DNA from the environment.
__________ are just temporary passengers that do not persist as stable residents of our bodies.
Transient Microbiota
Transposons, also known as "jumping genes," can have a wide-range effect on cells. Which of the following would not likely be an effect?
Transposons can repair damaged DNA.
Which of the following fungal species may cause infections in healthy individuals that have not suffered from interruption in the normal microbiotia?
Trichophyton species
Inflammation occurs in three general phases. Which phase is the first to occur after tissue injury?
Vascular changes phase
Mast cells are the key players in which phase of inflammation?
Vascular changes phase
Which of the following would be the best general description of a "virus?"
Viruses are acellular infectious agents.
Viruses do not infect which of the following organisms?
Viruses can infect all forms of life.
How is osmosis different from simple diffusion?
Water movement is driven by the concentration of solutes rather than its own concentration.
Which of the following is used in photosynthesis by both plants and cyanobacteria?
Water, sunlight, and carbon dioxide
Which type of lipid is incorrectly matched to its description?
Wax: Refers to any lipid which is solid at room temperature
When could hemolytic disease of the newborn occur?
When the father is Rh+ and the mother is Rh-
DNA microarrays reveal
Which genes are being expressed in a given cell
If you left out the safranin from your Gram staining procedure and observed your mixed culture after the application of alcohol-acetone, what would be the appearance of your Gram-positive and Gram-negative organisms, given you followed all steps in order and applied all other reagents correctly?
Your Gram-positives would appear purple, and your Gram-negatives would be colorless.
You are testing a chemical that you suspect is a mutagen. You set up an AMES test, and for your control (without the mutagen added to the bacterial culture) you observed only a few colonies. After you added the mutagen to the test sample, you observed similar results to your control—only a few colonies grew. What can you conclude about the chemical?
Your chemical is not mutagenic.
The chromatin is
a collection of DNA and protein.
Hyphae are
a collection of tubular structures that result from fungal growth.
Secondary immunodeficiences are commonly caused by __________.
a decline in immune system rigor
The cytoplasmic membrane could best be described as _________.
a highly selective, permeable barrier
An antibiotic is a drug which is wholly manufactured by chemical processes. a chemical that kills or removes bacteria, viruses, protozoa, helminths, or fungi. a naturally occurring compound that kills microbes or inhibits their growth. a preparation used to sterilize a person or object. medicine that removes pathogenic organisms from the body.
a naturally occurring compound that kills microbes or inhibits their growth.
A DNA vaccine involves placing genes into plasmid and introducing the plasmid into human cells. Human cells then transcribe and translate the genes to produce antigen which immunize the recipient. What is the source of the genes being introduced?
a pathogen
Criteria for assigning pathogens to a biosafety level include all the following except
ability to culture the pathogen using standard laboratory media and equipment.
Which molecule is the product of the intermediate step which is a direct input into the Krebs cycle?
acetyl CoA
You suspect that your patient is suffering from tuberculosis and obtain a sputum sample. Which of the following staining procedures would be the most appropriate to diagnose your patient?
acid-fast stain
If a superbug is resistant to an antibiotic due to horizontal gene transfer, the microbe is said to have mutational resistance. evolutionary resistance. acquired resistance. intrinsic resistance. natural resistance.
acquired resistance
Antibodies do all the following except
activate killing by T cytotoxic cells.
Which of the following types of transport would only be found in living cells?
active transport
In a(n) _________ infection, viral replication peaks, followed by immune clearance of the virus.
acute
A vaccine additive which enhances the bodys natural immune response is called an
adjuvant
which is NOT an opportunistic pathogen?
bacillus anthracis
Which of the following is an endogenous source of infection?
bacteria from the skin entering a surgical incision
Cell shape is determined by which of the following?
cell wall and cytoskeleton components
The success of the Gram stain is based on the difference in the composition of the _______ of bacterial cells.
cell walls
Animals are not typically microscopic, yet we cover them in microbiology because _________.
certain parasitic worms, or helminths, are usually spread in a microscopic form
Patients infected with Herpes simplex virus-1, the causative agent of fever blisters, go through periods of viral inactivity (where no active oral cankers appear) and outbreaks (where fever blisters are present). This type of individual is best defined as a(n) _______________.
chronic carrier
A key test used to differentiate Staphylococcus aureus from Staphylococcus epidermidis relies on the microorganism's ability to clot blood plasma fibrin. Based on this information, this distinguishing assay tests for the invasin
coagulase
which type of invasin is correctly matched with a representative organism?
coagulase- staphylococcus aureus
You receive results back from the lab that your patient is infected with Vibrio cholera. This organism is a _________-shaped organism.
comma
You are preparing a growth medium for an isolate that you obtained from a patient. You are adding yeast extract, glucose, peptones, malt extract, and ampicillin. Which kind of medium are you preparing?
complex & selective
Prokaryotic and eukaryotic ribosomes share which of the following features?
composed of a large and a small subunit and composed of protein and rRNA
Which of the following can cause primary immunodeficiencies?
congenital immunodeficiency
The genetic code
contains sense codons and nonsense codons.
All the following apply to T cells except
coordinate the humoral response by making antibodies.
Bacterial cells use DNA replication to:
copy their genetic material prior to binary fission.
A similarity between mitosis and meiosis is
copying DNA before the cell divides.
The type of medical equipment that regularly comes into contact with sterile body sites or the vascular system and must therefore be sterilized is classified as ________
critical equipment
which is NOT an example of a virulence factor?
dysbiosis
Which of the following pairs is not an example of a cytokine and its function?
eicosanoids: promote the replication and gathering of leukocytes
When electrons are removed from nutrients via an oxidation reaction, the coupled reduction reaction may be
either FAD → FADH2 or NAD+ → NADH.
Which of the following is not one of the four main groups of biomolecules?
electrolytes
DSM: The common cold is a(n) _________ disease.
endemic
The common cold is a(n) _________ disease.
endemic
What are the three factors of the epidemiological triangle?
environmental factors, etiological agent, and host factors.
During lytic replication of bacteriophage, which process uses factors from the host cell, rather than coded by the viral genome?
enzymes which transcribe and translate viral genes
Which cell type has a nucleus that appears to have two lobes connected by a thin band, has granules that contain diverse enzymes and antimicrobial toxins, and has mediators that are expelled in response to certain allergens and parasites?
eosinophils
The parts of an antigen that B and T cells recognize and mount an immune response against are called _________.
epitopes
In order to harvest energy from polysaccharides, lipids or proteins, cells must use ________ to break down these large macromolecules extracellularly before bringing them into the cell.
exoenzymes
botulism is caused by ingesting ______________
exotoxins
Which factor is responsible for many emerging pathogens in humans?
expanded host or tissue range of the pathogen
A double-blind, randomized study is being used to test the effectiveness of a new drug that targets the multi-drug resistant bacterium Clostridium difficile. Infected participants in the study were given either a placebo or the test drug and then monitored for one month for clearance of infection. This type of study can best be characterized as a(n)_________________.
experimental study
A patient with a newly transplanted organ is likely prescribed __________ in order to limit the risk of transplant rejection.
immunosuppressants
Which of the following is not part of the epidemiological triangle?
incidence rate
Adhesins
include molecules that bind to host factors such as fibronectin, sialic acid, and heparin / heparin sulfate.
To maintain a fluid plasma membrane in cold conditions, bacteria may modify their plasma membranes by
incorporating short unsaturated fatty acids into their membrane phospholipids.
What is the order of the five stages of infectious disease?
incubation period, prodromal phase, acute phase, period of decline, convalescent phase
An operon that is transcribed in response to the presence of a substrate is called a(n) _______.
inducible operon
In order to successfully and safety deliver a gene to a human cell, a virus vector must be
infectious but not pathogenic
Carbonic anhydrase is an enzyme that solubilizes carbon dioxide so that it can be removed from human tissues. Structural studies have shown that a zinc ion is required at the active site in order for the enzyme to function. In this example, zinc is best described as a(n) _____ that is required to form the functional _______ .
inorganic cofactor; holoenzyme
Which of the following allergies and treatments is mismatched?
insect bite/sting allergy: continued preemptive treatment with an injected antibody preparation that ties up the patient's IgE antibodies
Robert Koch helped establish the germ theory of disease by discovering that anthrax was caused by a disease. After he isolated and purified the same bacteria from several diseased animals, what would be the next step in order to show that this bacteria caused anthrax?
introduce the bacteria into a new mouse to see if it established the same infection
Host-microbe interactions
involve a dynamic give-and-take between the microbe and the host.
Chloride (Cl-) is most likely to form a(n) _________ bond with _________.
ionic; Na+
In direct ELISA, the reporter enzyme
is bound to the detection antibody and chemically modifies an added substrate to generate a colorimetric or chemiluminescent change
Gluconeogenesis
is building glucose from non-sugar starting materials and can be accomplished by funneling intermediates from glycolysis, the Krebs cycle, and lipid or protein catabolism and an example of biosynthesis.
The major histocompatibility complex type I (MHC I) _________.
is found on all body cells except red blood cells
mRNA _______.
is translated to build proteins
The goal of the streak plate technique is to
isolate a pure culture for study from a single colony.
14C is an _______ of _______.
isotope; carbon
When a virus has an envelope,
it likely escapes its host cell by budding.
Which organs are particularly susceptible to damage by certain antimicrobial drugs? stomach and intestines heart and lungs pancreas and gallbladder brain and spleen kidneys and liver
kidneys and liver
Eradication of an infectious disease means that there are no longer any cases of it anywhere in the world. Which of the following types of infectious diseases would be the most difficult to eradicate?
latent infectious diseases
Which method of hiding from the host immune system is incorrectly matched with its description?
living intracellularly: a pathogen resides on the surface of a host cell where it is hidden by host cell surface molecules
When a healthcare provider diagnoses a reportable disease, who do they document the case with?
local public health authority
You would like to calculate the generation time of an unknown organism and set up a culture. During which of four distinct growth phases would it be best to collect data?
log phase
The liquid contained within the lymphatic vessels is called _________.
lymph
A therapeutic index is a ratio between toxicity versus half-life. patient survivability versus patient allergies. patients that benefited from drug versus patients that experienced side effects. maximum safe dose versus minimum effective dose. potential patients not ruled out due to drug interactions or contraindications versus patients that experienced side effects.
maximum safe dose versus minimum effective dose.
Which of the following does not describe cellular respiration?
may include multiple pathways including glycolysis, an intermediate step, the Krebs cycle and fermentation
Protozoans are mainly grouped by their __________.
means of motility
Part complete Which temperature group are most pathogens associated with?
mesophiles
Whole cells or viruses are engulfed and imported into a eukaryotic cell via _________.
phagocytosis
Examples of healthy host-microbe interactions with our normal microbiota include all except
microbiota disruption.
Besides biochemical tests, which techniques are also useful for identifying a bacterial specimen?
microscopy and molecular genetics techniques and observation of general culture characteristics
Desensitization immunotherapies are least effective to treat allergies from which of the following?
milk
Prions are
misfolded proteins which can cause normal versions to also misfold.
The endosymbiotic theory states that nonphotosynthetic prokaryotes merged with an ancestral cell and, over evolutionary time, became___________. Some of these new cells engaged in a second merging event with a photosynthetic prokaryote, possibly a cyanobacterium. The photosynthetic prokaryote eventually—over evolutionary time—became __________.
mitochondria; chloroplasts
The enzymes superoxide dismutase and catalase work together to convert reactive superoxide ions back to _________.
molecular oxygen
A(n) _________ is formed when two or more atoms bond together; a(n) _________ is used to describe molecules that are composed of more than one type of element.
molecule; compound
Once equilibrium is reached,
molecules move, but there is no net movement in a particular direction.
Which cell type is the largest agranular white blood cell, mature as they leave the circulatory system, and increase cell levels due to chronic infections and inflammation, autoimmune disorders, and certain cancers?
monocytes
DSM: During the Ebola outbreak between 2014 and 2016, according to the CDC an estimated 29,000 cases of Ebola were reported. About 12,000 people died. Therefore, the _________ rate was about 41%.
mortality
During the Ebola outbreak between 2014 and 2016, according to the CDC an estimated 29,000 cases of Ebola were reported. About 12,000 people died. Therefore, the _________ rate was about 41%.
mortality
Mitochondria do not participate in which function?
motility
Escherichia coli living in the human large intestine is known to produce vitamin K and B-complex vitamins in exchange for a nutrient-rich habitat. This host-microbe interaction is an example of __________.
mutualism
The symbiotic relationship represented by the production of vitamin K in the human large intestine by Escherichia coli is best described as _________.
mutualism
Fungal infections are called
mycoses.
Bacitracin is made naturally by the bacterium Bacillus subtilis and is primarily only used to target skin infections caused by Gram-positive bacteria. This type of chemotherapeutic drug would best be characterized as a(n) ____________. broad-spectrum synthetic drug narrow-spectrum antibiotic broad-spectrum antibiotic narrow-spectrum semi-synthetic drug
narrow-spectrum antibiotic
A patient fully recovered from Ebola with minor medical support. This was the result of ____________.
naturally acquired active immunity
A mother is breastfeeding her infant son and transferring crucial antibodies to him. This will result in _________.
naturally acquired passive immunity
Antibiotics are _________________. a superfamily of drugs that work by blocking cell wall construction naturally occurring antimicrobial compounds naturally occurring antibiotics chemically modified to improve their pharmacological actions and/or stability wholly manufactured by chemical processes
naturally occurring antimicrobial compounds
Which of the following would be considered a symptom?
nausea
Which of the following pH classifications make up most of the pathogens we know today?
neutralophiles
Although antivenom can save lives, it can also cause what type of reaction in certain patients?
nonautoimmune type III hypersensitivity
The most common drugs that block replication are ________.
nuceloside analogs
Prokaryotic cells house a single circular chromosome in their __________.
nucleoid region
The DNA of a prokaryotic cell is found within the ___________.
nucleoid region
What does the plaque assay determine?
number of bacteriophage in a sample
The best antifungal treatment option for a diaper rash caused by Candida sp. would be _________. caspofungin acetate mebendazole chloroquine nystatin
nystatin
Van der Waals interactions
occur when temporary dipoles within molecules form that are not the result of hydrogen bond to O, N, or F atoms.
Patients with conjunctivitis often can be seen rubbing their itchy, irritated reddened eye(s). Based on this symptom of infection, which of the following modes of transmission is most likely?
ocular
Genes that are essential for survival of a bacterial cell would most likely be located _______.
on the chromosome(s)
Compared to a solution with a pH value of 4, a solution with a pH value of 2 has ________ H+ ions.
one hundred times as many
In an operon, the repressor binds to the _______.
operator
Which of the following is an outcome of complement activation?
opsonization, cytolysis, and inflammation
Which term represents the temperature that bacteria grow the fastest at?
optimal
Which of the following molecules is not found in the plasma membrane?
peptidoglycan
Bacteria with flagella distributed all over the cell surface are described as having:
peritrichous flagella
DSM: Infectious mononucleosis is spread through kissing or other close contact between the host and a healthy individual. This is considered _________.
person-to-person transmission
Infectious mononucleosis is spread through kissing or other close contact between the host and a healthy individual. This is considered _________.
person-to-person transmission
The role of healthcare workers in the management of disease outbreaks
should be addressed through periodic training and re-training.
________________ are complexes that remove iron from transferrin for their own use.
siderophores
What are cytokines?
signaling proteins that help cells communicate with each other, initiating and coordinating immune actions
Allografts are
similar to the host, but not genetically identical.
Which of the following can be determined using simple stains?
size, shape and cellular arrangement
Which is not a cancer linked to a specific virus?
skin cancer
Bacillus subtilis is naturally found in the soil. B. subtilis is known to contaminate rice, which, if undercooked and ingested, can lead to gastroenteritis. In this example, the reservoir for B. subtilis is the ________, and the source of infection is the ___________.
soil; rice
Which of the following viral genomes is immediately ready for translation after the virus gains entry into the cell?
ssRNA+
In which growth phase do bacteria produce antibiotics and endospores?
stationary phase
An indirect ELISA is pictured. In which step is the detector antibody added to the assay?
step 3
Oncogenic viruses
stimulate uncontrolled host cell division.
The human immunodeficiency virus (HIV) selectively infects any cell which carries the CD4 surface glycoprotein. Which immune function will be impaired?
stimulation of macrophage, B and TC cells
Escherichia coli O157:H7 may cause servere illness. "O157:H7" is the _______ designation of the organism.
strain
You are observing an unknown organism under the microscope. The organism is spherical and arranged in long chains. You are observing _________.
streptococci
The branches of adaptive immunity are
the cellular response and the humoral response.
All of the following can make interpreting the Gram stain difficult except
the culture is between 24 and 48 hours old.
which correctly describes infectious Dose-50 (ID 50)?
the more infectious the pathogen is, the lower the ID 50
What is the major challenge with developing new synthetic antimicrobials? the need to screen thousands of potential candidates choosing which bacterial structure to target finding the right dose deciding what bacteria to test it on figuring out if the drug is bacteriostatic or bactericidal
the need to screen thousands of potential candidates
Isotopes are atoms of the same element that differ in
the number of neutrons found in the nucleus.
What is herd immunity?
the only protection available to those who are unable to receive immunizations due to medical reasons Submit
You perform a plaque reduction neutralization test on a patient who is recovering from a suspected case of Dengue fever, caused by Dengue virus. You observe that there is increased number of plaques on the test plate compared to the control. THese results indicate that:
the patient lacks antibodies to Dengue virus
The rough ER and the smooth ER are distinguished from each other by
the presence or absence of membrane-bound ribosomes.
herd immunity describes
the protection conferred to non-immunized people when a sizable portion of the rest of the population is immunized
An atom is best described as
the smallest unit of an element.
The rabies virus primarily affects the nervous system. The specificity that the rabies virus has for neuronal host cells is primarily dictated by __________________________.
the spikes that protrude from its viral envelope
In the typical ATP-ADP cycle, which part of the ATP molecule is removed when energy is released and added back when energy is stored?
the terminal phosphate group
Viruses are considered to be non-living pathogens for which reason?
their lack of metabolic processes
The minimum temperature needed to kill all microbes in a sample within ten minutes is called the
thermal death point.
Biochemical tests are useful to microbiology because
they can be used to identify microbes and to identify potential pathogens in clinical samples and they can be used to detect metabolic end-products, intermediates, or particular enzymes.
Epidemiological measures are useful tools because:
they help determine which diseases may need greater public health campaign or prevention efforts.
Which of the following key chemical mediators in inflammation is not matched to its function?
thromboxanes: reduce pain receptor stimulation and reduces fever Submit
DSM: Lyme disease is spread _________.
through biological vectors
Lyme disease is spread _________.
through biological vectors
Which of the following are primary lymphoid tissues?
thymus and bone marrow
What is edema?
tissue swelling
Which property is not used to classify viruses?
tissue types infected
The amount of antibody present in the blood is termed the antibody ________.
titer
What is the purpose of the streak plate technique?
to obtain a pure culture from a mixed or unknown source
What is the role of B cell receptors (BCRs) and T cell receptors (TCRs) in the immune response?
to recognize specific epitopes of an antigen
What two types of patients help demonstrate that cancer can be considered a failure of the immune system?
transplant patients and HIV/AIDS patients
the preference of a pathogen for a specific host is also known as _____________
tropism
A microbe with a low ID50 does not necessarily cause severe disease.
true
Which of the following is an indirect cell-counting method?
turbidity measurement
Each antibody molecule consists of
two light and two heavy protein chains.
You attended a BBQ and ate a variety of foods, including pototato and egg salads. After you arrive home a few hours later, you display symptoms of food poisoning (vomiting, diarrhea, cold sweats, etc). Which type of exotoxin did you likely ingest?
type 1
Exotoxins are often classified into three main families based on their mode of action. Which of the following pairs is correctly matched?
type III - intracellular toxin
Lupus is a ________ hypersensitivity characterized by ______.
type III; a rash across cheeks and nose, fatigue, and joint pain
Artemisinin-based combination therapies are used to treat chronic Toxoplasma gondii infections. life-threatening multidrug resistant infections, especially those caused by Pseudomonas aeruginosa, Acinetobacter baumannii, or Klebsiella pneumoniae. mild to moderate C. difficile infections that don't have complications. uncomplicated and severe cases of malaria. severe fungal infections such as Cryptococcus meningitis and systemic Candidiasis infections.
uncomplicated and severe cases of malaria.
Helicase
unwinds the DNA.
Part complete Where are cilia found in the human body?
upper respiratory tract
Which of the following nitrogen bases is found only in RNA and NOT in DNA?
uracil
Which of the following prion diseases may be acquired by eating beef contaminated with a cattle prion?
variant CJD
Which mode of transmission is not addressed by transmission precautions?
vector
DSM: HIV-positive mothers can transmit the virus through breastfeeding. This is considered __________ transmission.
vertical
HIV-positive mothers can transmit the virus through breastfeeding. This is considered __________ transmission.
vertical
Antivirals do not target ________. viral replication viral assembly viral attachment viral ribosomes
viral ribosomes
Which of the following suffixes would be used to describe a viral family?
viridae
The degree or extent of disease that a pathogen causes is
virulence
Certain traits that allow pathogens to create infection and cause disease are termed
virulence factors.
A previously undescribed infection has been detected among inhabitants in an isolated village in a remote tropical rainforest. When serum from an infected individual is passed through a filter, the infection can be transmitted to laboratory animals. Nothing is observed when the serum is examined with a light microscope at the highest magnification. Biochemical tests show the presence of RNA and protein but no carbohydrates or lipids. This data is consistent with what type of infectious agent?
virus
Which of the following microbes is considered "nonliving?"
viruses
Challenges in developing effective antiviral drugs with minimal side effects to the patient include
viruses use the cell's own machinery and metabolism for replication.
