Quick Quiz 1-6, lecture 1-10, DSM 1-6, lab midterm review, chapters 11-15, lab, 16-21
Referring to the following reaction, identify the product of the reaction. 3H2 (g) + N2 (g) → 2NH3 (g)
2NH3 (g)
A codon consists of __________ nucleotides.
3
An indirect ELISA is pictured. In which step is the detector antibody added to the assay?
3
How many questions are needed in this dichotomous key to determine if the unknown is Bacteroides?
3
Which stage marks the progression of HIV to AIDS?\
3
Refer to the numbered steps in the figure when answering the question. Two carbons in the form of acetyl-CoA enter the Krebs cycle by joining with oxaloacetic acid, a 4-carbon molecule. During which step does carbon leave the Krebs cycle in the form of CO2?
3 and 4
Which of the following best describes the eukaryotic kingdom Fungi?
Includes yeasts, molds, and mushrooms. Unicellular and multicellular. Has a cell wall.
How would one increase the concentration of a particular polypeptide in a cell?
Increase the level of transcription
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.
Which of the following steps is found in the lysogenic replication pathway but not in the lytic replication pathway?
Integration
Choose the one that is correctly matched.
Intermediate level germicides: destroy Mycobacterium tuberculosis but not endospores.
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?
Intravenously
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
__________ is used to sterilize medical supplies and food.
Ionizing radiation
Which of the following is an incorrect statement about iron-binding proteins?
Iron-binding proteins are also referred to as "siderophores."
_____________ 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.
Why is vasodilation important to tissue repair?
It allows for an increased delivery of oxygen, nutrients, and phagocytes to the site of damage.
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.
How does the protozoan Trypanosoma evade detection by the immune system?
It can change the surface antigens frequently, preventing the immune system from tracking it.
Why is a release of endotoxin into the bloodstream potentially deadly?
It can lower blood pressure and cause the patient to go into shock.
Of the following statements, which does NOT apply to a microorganism that has a fertility plasmid?
It can undergo vertical gene transfer.
Choose the false statement about the prokaryotic cytoskeleton.
It contains actin and tubulin.
Julia has contracted Clostridium botulinum from a contaminated food source. What is the main reason that antibiotics should not be used to treat Julia?
It could have increased toxin release from the bacteria.
How does the Gram staining procedure differentiate between Gram-negative and Gram-positive bacteria?
It differentiates between Gram-positive and Gram-negative bacteria based on cell wall composition.
Why is the unknown in this example not Pseudomonas?
It ferments lactose.
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.
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
Which of the following terms about bacteriophage replication is mismatched?
Lytic replication: phage conversion
Which of the following is not a Staphylococcus aureus virulence factor?
M-protein
This image shows the results of three different bacterial species that were streaked onto MSA and allowed to grow overnight at 37ºC. What do the observed results of Micrococcus luteus indicate?
M. luteus is not a halophile or facultative halophile
The majority of secondary lymphoid tissue is called ________, and includes Peyer's patches, tonsils, and the appendix.
MALT
After excess lymph drains from our tissues, it is shuttled to the lymph nodes and ________, where waste filtering and pathogen detection take place.
MALT tissue
___________ is the minimum concentration of the drug that kills at least 99.9 percent of the bacteria present.
MBC
Put the following steps of bacterial replication in the correct order, starting from a parent cell. 1. Cell elongation 2. Septum formation 3. Chromosome replication 4. Separation of daughter cells
3, 1, 2, 4
Why is a specimen smaller than 200 nm not visible with a light microscope?
Anything smaller than 200 nm cannot interact with visible light.
The three main pathways for complement activation all have the same general outcomes. Which of the following would not be an outcome?
Apoptosis
Each of the following is a kingdom of eukaryotes except:
Archaea
Which of the following statements about constitutive genes is false?
Constitutive genes produce their proteins when a cell encounters a specific environmental change.
Which of the following is considered a major category of transmission of disease?
Contact, vehicle, and vector transmission
Which of the following describes the function of lysosomes?
Contain a wide variety of hydrolytic enzymes that break down substances engulfed by the cell.
What would have been the possible source for this patient's infection?
Contaminated water in Honduras was used for drinking or cooking.
Which of the following RNA virus families includes the virus that causes severe acute respiratory syndrome (SARS)?
Coronaviridae
SARS is caused by a(n)
Coronavirus
Which of the following methods uses an electronic counter to enumerate bacteria as they pass through a tube?
Coulter counter.
Which microorganism requires the low pH inside a phagolysosome in order to reproduce?
Coxiella burnetii
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
Even though the CFTR gene is in every cell of the body, only certain cells contribute to the CF phenotype due to CFTR mutations. Discuss a possible explanation for this
Epigenetic modifications (such as DNA methylation) may silence production of the CFTR gene in certain cell types
Burkitt's lymphoma is a possible complication of which disease?
Epstein-Barr virus
The nickname "the kissing disease" refers to an infection caused by which pathogen?
Epstein-Barr virus
Which of the following viruses and cancer links are mismatched?
Epstein-Barr virus: adult T-cell leukemia.
Which staphylococcal infection is not correctly matched with its description?
Erysipelas: A milder form of impetigo with only localized inflammation and mild pain
An important source of vitamin K in the intestine comes from which species?
Escherichia coli
Using your knowledge of organism's gram staining properties, which of the following organisms would grow on EMB?
Escherichia coli
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 germicides will also sterilize?
Ethylene oxide.
Which of the following statements is false?
Eukaryotes have a much simpler genetic makeup than prokaryotic cells.
Which of the following processes removes substances from the cell?
Exocytosis
What does the term facultative anaerobe mean?
Facultative anaerobes can grow with or without oxygen. More growth is evident when oxygen is present.
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 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
Which of the following cellular structures is matched with their correct function?
Fimbriae - allow a cell to stick to surfaces or each other
Which of the following RNA virus families includes the virus that causes dengue fever?
Flaviviridae
Which of the following methods uses laser light to detect fluorescently labeled cells passing through a narrow channel to enumerate bacteria?
Flow cytometer.
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
Host antibodies against the influenza virus are developed against ___________.
HA and NA spikes
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.
What is the causative agent for this sexually transmitted disease?
Haemophilus ducreyi
Meiosis is characterized by:
Haploid chromosomes
Which of the following describes zygospores?
Haploid gametes found at the tips of hyphae.
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.
How did this man most likely become exposed to this disease agent?
He is likely to have been exposed while hunting elk in Colorado during his childhood.
Which of the following is a plausible mechanism for contracting pseudomembranous colitis?
Heavy antibiotic usage
Your patient complains of upper abdominal pain, heartburn, and indigestion. Based on the patient's case history and clinical presentation, you believe that your patient has a stomach ulcer caused by a resident microorganism. You ask the microbiology laboratory to culture the stomach pathogen from a gastric tissue biopsy. Which of the following bacterial genera would you expect the microbiology laboratory to observe in the patient's culture?
Helicobacter
Which of the following organisms would have enzymes that would function best in a low pH?
Helicobacter pylori
Immune cells that secrete cytokines and activate other immune cells are:
Helper T-cells
How do helper T-cells and cytotoxic T-cells work together?
Helper T-cells produce cytokines to activate other cells of the immune system.
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 is a characteristic of flatworms?
Hermaphroditic.
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.
Which proteins on the antigen-presenting cell are recognized by the helper T-cell?
MHC proteins
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 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?
Mutations
The causative agent for leprosy is the bacterium __________.
Mycobacterium leprae
Which of the following characteristics help to explain why Mycobacterium leprae infects the peripheral nervous system?
Mycobacterium leprae prefers a lower growth temperature.
Which of the following infectious agents is a reemerging pathogen?
Mycobacterium tuberculosis
Which of the following anatomical parts is a muscular tissue that makes up the bulk of the heart?
Myocardium
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
Of the following, which could NOT be an electron acceptor in a redox reaction?
NADH
How do electrons get from glycolysis, the intermediate step, and the Krebs cycle to the electron transport chain?
NADH and FADH2 transport electrons to the electron transport chain.
Which of the following molecules would not change the pH of an unbuffered solution?
NaCl
Primary amoebic meningoencephalitis is caused by
Naegleria fowleri
Which of the following would not be considered a beneficial characteristic when choosing a new antimicrobial drug?
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.
What is the name for the dark-staining bodies observed in the brain cells from this patient?
Negri bodies
Which of the following outcomes is observed during Rabies virus pathogenesis?
Negri bodies are a diagnostic sign of Rabies virus infection.
According to the CDC, Clostridium difficile, carbapenem-resistant Enterobacteriaceae (CRE), and multidrug-resistant strains of __________ are classified as urgent threats.
Neisseria gonorrhea
Analysis of the spinal tap shows the presence of Gram-negative bacteria cocci; for this age group which bacteria would be the probable cause of these symptoms?
Neisseria meningitidis
Meningitis and gonorrhea are caused by
Neisseria species
A 48-hour old infant is brought to the clinic with signs of severe bacterial conjunctivitis (infection of the eye). The infant was born at home, with the birth assisted only by an unlicensed midwife, and no pharmaceutical interventions performed on the mother or infant. Which infectious agents is the likely culprit?
Neither Chlamydia trachomatis nor Neisseria gonorrhoeae should be ruled out without further testing.
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
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 primary skin lesion is incorrectly matched with its description?
Papule: Sore of irregular size and shape that results as epidermal and dermal skin layers are destroyed
Which of the following is true about ribosomes?
Prokaryotic ribosomes have a lower overall mass and diameter than eukaryotic ribosomes.
Which of the following is the single most important procedure for a healthcare worker to prevent hospital-acquired infections (HAI)?
Proper handwashing
The eukaryotic cytoskeleton performs all of the following except:
Protects the cell from stress.
The main functions of the Golgi apparatus include:
Protein modification, production of lipids, distribution of products.
From which phrase is the term "prions" derived?
Proteinaceous infectious particles
What cellular macromolecules make up the complement pathway?
Proteins
__________ comprise at least half the mass of a plasma membrane.
Proteins
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
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
_________ is the ability of an infectious agent to cause disease.
Pathogenicity
Which of the following enzymes is incorrectly matched with its function?
Polymerase I - copies DNA on the leading and lagging strands.
Which of the following would not move freely across the cytoplasmic membrane?
Positively charged hydrogen ions
Choose the true statement about post-translational modifications.
Post-translational modifications include phosphorylation, trimming, and addition of organic factors.
__________ is an example of a halogen germicide.
Povidone-iodine
How can health care workers reduce the occurrence of nosocomial infections?
Practice more stringent aseptic techniques
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
When traveling to regions where malaria is common, what is the recommendation?
Preventive antimalarial drugs should be taken daily while traveling in endemic areas.
__________ are considered to be nonliving, do not contain genetic material, and do not replicate.
Prions
How does the number of infectious prions increase?
Prions transform normal proteins into the misfolded beta-pleated sheet configuration; therefore, prions multiply by conversion.
Choose the features of the prokaryotic ribosome that support the endosymbiotic theory.
Prokaryotes have a ribosome with a 70S sedimentation rate.
The primary function of feedback inhibition is to allow the cell to __________.
produce only the required amount of product and to stop when a sufficient quantity is produced
Which of the following is not a function of a molecular second line defense?
producing antibodies specific to the bacterial infection
The dominant genus in the vaginal microbiome of reproductive-age women, Lactobacillus, acts to limit infection by
producing lactic acid, hydrogen peroxide, and bacteriocins.
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
What type of pre-transcriptional regulation is the most likely to turn off the production of a substance that is already plentiful?
repressible operons
Which is not a cancer linked to a specific virus?
skin cancer
Where are lipids made in the cell?
smooth endoplasmic reticulum (ER)
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
Transduction that involves a temperate phage integrating into the host cell genome is called __________.
specialized transduction
Frequent mutations in Influenza A change the protein makeup of hemagglutinin (HA) and neuraminidase (NA) __________.
spikes
Viral __________ help viruses attach to and gain entry into host cells.
spikes
Mosquitoes infected with Plasmodium pass on which of the following to the host?
sporozoites
Which food is the most likely source of the infection?
sprouts
Which of the following viral genomes is immediately ready for translation after the virus gains entry into the cell?
ssRNA+
Enzymes catalyze reactions by __________.
stabilizing and arranging the reactants for the reaction to occur more efficiently
Organisms that form a cluster of sphere-shaped bacteria would be described as having a _________ arrangement.
staph
During the __________ phase of bacterial growth in a closed system, the number of cells dying equals the number of cells dividing.
stationary
In which growth phase do bacteria produce antibiotics and endospores?
stationary phase
RNA that has hydrogen bonded to itself forms a
stem loop
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
Which of the following arrangements is sometimes referred to as having a beads-on-a-string appearance?
streptococci
You are observing an unknown organism under the microscope. The organism is spherical and arranged in long chains. You are observing _________.
streptococci
Glycolysis makes ATP using ______.
substrate-level phosphorylation
In glycolysis, the second stage is known as the "payoff stage." Which type of phosphorylation occurs in this stage?
substrate-level phosphorylation
Which nutrient is responsible for the development of cavities in teeth?
sucrose
Glycolysis literally means
sugar splitting
A person who attended a picnic early in the day develops a very high fever and is unresponsive by the evening. This person most likely has been exposed to a(n)
superantigen
Measles viruses are capable of inactivating host defenses by
suppressing the immune system.
Tachycardia and a drop in blood pressure are signs of _________ affecting the __________.
systemic anaphylaxis; cardiovascular system
An anticodon is found on __________.
tRNA
Which of the following is involved in bringing amino acids to the ribosomes?
tRNA
Which type of RNA carries in amino acids and adds the amino acids to the "A" site in the ribosome?
tRNA
Which of the following does not belong to the kingdom Protista?
tapeworms
Which aspect of the polymerase chain reaction (PCR) is mismatched with its description?
template DNA: the DNA to be copied; must be present at a high concentration for the procedure to work
RNA polymerase is guided by the
template strand of DNA.
UV radiation can result in __________ in a cell's DNA.
thymine dimers
Which of the following are primary lymphoid tissues?
thymus and bone marrow
What type of infection is shown?
tinea
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
The primary purpose of bacterial endospores is:
to allow certain cells to enter a dormant state.
Which of the following cell shapes look like a comma?
vibrio
The purpose of the streak plate technique is:
to dilute the culture on the plate so individual colonies are easily observed.
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
Which type of bacterial toxin is matched incorrectly with its description?
toxemia: a toxin produced during a viral infection
Which of the following is not a mycosis?
toxoplasmosis
What risk is there, if any, to the unborn child during passage through the birth canal?
trachoma
While on a medical volunteer trip to an impoverished country, you encounter a patient whose eyelids are turned inward as shown. What is the cause and the best treatment?
trachoma; single dose of oral azithromycin
A small child presents to the pediatric office with a reddened sclera, itchy eyes, and a watery, clear discharge from the affected eye. The most likely diagnosis is
viral conjunctivitis.
Antivirals do not target ________.
viral ribosomes
A __________ is a single particle made up of genetic material encased in a protein shell.
virion
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.
Which of the following is an example of intrinsic resistance?
The bacterium Bacillus cereus produces endospores during environmentally harsh conditions, enabling it to survive cooking processes.
Why do symptoms persist after antibiotics have been used to treat and remove the bacterial infection?
The blebs containing lipid A are still present in the blood and in the tissues.
Which of the following is a characteristic of amoeboid protozoans?
Utilize pseudopods for movement.
Which of the following statements is incorrect?
Vaccines cause autism.
__________ contain mainly water and other substances and are mainly found in plants, fungi, and certain prokaryotes and protists.
Vacuoles
Which is the true statement about vaginosis and vaginitis?
Vaginitis describes vaginal inflammation while vaginosis does not.
___________ 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?
Vancomycin
Which of the following antimicrobial drugs would not be appropriate to treat a patient with walking pneumonia?
Vancomycin
In a(n) _________ infection, viral replication peaks, followed by immune clearance of the virus.
acute
After translation, protein modifications are necessary for a final functioning product. Which of the following is NOT part of protein modification?
addition of a methionine
Although each of the following viral groups causes acute respiratory illnesses, ________ can also be associated with conjunctivitis, gastroenteritis, or cystitis.
adenovirus
A vaccine additive which enhances the body's natural immune response is called a(n)
adjuvant
Which of the following events does not put you at risk for contracting a Francisella tularensis infection?
adopting a dog from an animal shelter
Which of the following is another term for a virus attaching to the host cell?
adsorption
Which of the following would be the best choice for an antiseptic used on skin?
alcohol
_________ live in environments with extremely high pH.
alkaliphiles
Genital warts are transmitted by __________.
all answers are correct
T-cell precursors are made in the __________ and mature in the __________.
bone marrow; thymus
Droplet and airborne precautions
both involve diseases of the respiratory system and/or diseases transmitted through a respiratory route.
The paralytic toxin from C. botulinum differs from the toxin from C. tetani in that __________.
botulism results in flaccid paralysis and tetanus results in a spastic paralysis
Which test confirmed the presence of this prion disease?
brain scan
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 ___________.
broad-spectrum antimicrobial drugs
Most prokaryotic cells reproduce
by binary fission
How is this disease transmitted?
by direct contact with an open sore during sexual activity
C3 convertase cleaves C3 into __________ and ___________.
c3a and c3b
Based on the animation, which of the complement proteins can directly bind to the surface of a bacterial cell?
c3b
Compared to a 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.
Which of the following diseases is not caused by prions?
cancer
What type of cancer is more likely to develop in people who have had papillomavirus infections?
cancer of the tonsils
The protein shell that packages and protects the genome and also accounts for the bulk of a virion's mass is called a _________.
capsid
Neisseria meningitidis, which causes meningococcal meningitis, is capable of triggering sporadic disease outbreaks by which of the following methods?
capsular switching
What is an example of a virulence factor that is related to immune system evasion?
capsule
The biochemical test shown in the image is used to detect the presence or absence of a certain enzyme that differentiates staphylococci (positive) from streptococci (negative). Using your knowledge of the test and the results observed in this image, name the enzyme.
catalase
The avian influenza virus host range includes all of the following except ______.
cattle
Which does not apply to ringworm infections?
caused by a worm
Based on the recommendations in this textbook, which antibiotic would be the treatment of choice for this disease?
ceftriaxone and azithromycin
Variant CJD is transmitted via __________.
contaminated meat
What is currently the most crucial way of reducing incidence of dengue, yellow fever, chikungunya, and Zika?
control mosquito levels
Enzyme specificity allows for __________.
controlled cellular processes
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.
Using the same simple key starting with Step 2 the following characteristics have been observed: •Cells are not spherical in shape •Cells are not rod-shaped •Cells are club-shaped •Using these characteristics, which genus of organism do we have?
corynebacteria
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
Smoking causes lung cancer. The validity of this statement was first verified by ________ studies.
cross-sectional
A two-year-old child presents to a pediatric practice with a barking cough and loud wheezing. The parent is alarmed and insists on antibiotics. What is the likely diagnosis, and are antibiotics appropriate?
croup / no, most cases are viral
Signaling proteins that support cell-to-cell communication, and initiate and coordinate immune responses are called ___________. Examples of these signaling proteins are interleukins and interferons.
cytokines
The structural framework in a cell is the
cytoskeleton
An exotoxin that has the ability to kill or damage host cells is referred to as a(n)
cytotoxin
Which of the following is NOT an accepted treatment for warts?
daily application of tincture of iodine to the wart surface
Pus is comprised of
dead phagocytes.
During the __________ phase of bacterial growth in a closed system, the number of cells dying exceeds the number of cells dividing.
death
What is the typical incubation period for prion diseases?
decades
The __________ is the time in minutes that it takes to kill 90% of a microbial population at a given temperature.
decimal reduction time
Each organic and inorganic component in __________ media is completely known and quantified.
defined
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
A diagnostic test that is specific is described as____________.
detecting only the virus(es) of interest
The term "redundancy" in molecular biology refers to __________.
different codons that code for the same amino acid
Viral genetic reassortment is most likely to occur when __________.
different viral strains infect the same cell
Bacterial species can be visually distinguished from each other based on their metabolic properties when grown on __________ media.
differential
Zika virus is best described as a(n) _________ virus with a ________ genome.
enveloped, ssRNA+
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
Botulism is generally associated with ingestion of the toxin produced by Clostridium botulinum. The activity of the toxin will result in __________.
flaccid paralysis
Virulence factors associated with this organism include all of the following, EXCEPT __________.
flagella
Which of the following features of Salmonella prevent it from being phagocytosed?
flagella
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
Which of the following mutations is the most detrimental to the cell?
frameshift mutation
The core component of __________ cell walls is chitin.
fungal
Which of the following is not a domain?
fungi
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
The organism Candida albicans is classified as a __________ and grouped within the domain _________
fungus; Eukarya
Pyocyanin, a greenish-blue pigment produced by pseudomonads, acts as a virulence factor by
generating reactive oxygen species.
A micelle forms in water when the __________ component of the molecule is forced to the center of the structure.
hydrophobic
__________ are a collection of tubular structures, either septate or aseptate, which allow for growth in most fungi.
hyphae
Dysentery can lead to ________ and/or organ failure if medical attention is not sought in time.
hypovolemic shock
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.
The correct order of steps to follow when using recombinant DNA technology to produce a protein for pharmacological use is
isolate the desired gene — insert the gene into an expression vector — transform host cells with the expression vector — grow the transformed cells into suitable quantities — purify the expressed protein.
14C is an _______ of _______.
isotope; carbon
Boys should receive the HPV vaccine because __________.
it can prevent oropharyngeal cancer caused by having oral sex with a woman infected with HPV
What is the function of eosin and methylene blue in EMB media?
it functions in both the selection of gram-negative organisms and the differentiation between lactose fermentors and non-lactose fermentors
Influenza differs from the common cold in that
it has a greater fatality rate.
When a virus has an envelope,
it likely escapes its host cell by budding.
Which of the following scientists investigated processes for aseptic surgery?
joseph lister
The presence of ________, a waterproofing protein, in epidermis prevents many microorganisms from gaining access to the body.
keratin
Which organs ae particularly susceptible to damage by certain antimicrobial drugs?
kidneys and liver
Which of the following prion diseases was also known as laughing disease?
kuru
How are prions different from other infectious agents?
lack nucleic acid
During the __________ phase of bacterial growth in a closed system, bacteria alter their gene expression in response to their new setting.
lag
Which component of the lower respiratory tract is incorrectly matched with a function or description?
larynx: contains the mucociliary escalator
According to the figure, when were measles the most prevalent in the US?
late 50s
Stress such as fever, sunburn, or hormone level changes can trigger the reactivation of a _________ viral infection.
latent
Which of the follow is false concerning the tetanospasmin toxin?
leads to flaccid paralysis
Mitochondria share all the following features with bacteria except
linear DNA and 80S ribosomes.
Which of the following would NOT affect the ability of an enzyme to act on a substrate?
lipid concentration in the plasma membrane
If not handled promptly with the correct treatment regime, which of the following infections may develop and be considered as life threatening?
liver and lung abscesses
When a healthcare provider diagnoses a reportable disease, who do they document the case with?
local public health authority
During the ________ phase of bacterial growth in a closed system, there is an exponential increase in bacterial cell number.
log
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
What diagnostic tool is used to confirm a diagnosis of meningitis or encephalitis?
lumbar puncture
Which of the following paths does Cryptococcus neoformans take to get to the CNS?
lungs → macrophages → lymphatic system → blood → CNS
The liquid contained within the lymphatic vessels is called _________.
lymph
Swollen ________ indicate that a foreign antigen is present, and leukocytes are rapidly multiplying to mount an immune response.
lymph nodes
Lymphogranuloma venereum differs from the infection caused by the trachoma biovar of Chlamydia trachomatis in that
lymphogranuloma venereum may result in the formation of buboes and tissues necrosis.
Which of the following organelles breaks down worn-out organelles?
lysosomes
Lytic bacteriophages use the enzyme __________ to break down host cell walls that allow the release of newly formed bacteriophage.
lysozyme
Which enzyme is responsible for breaking down a host bacterium's cell wall so that the virus can leave the cell?
lysozyme
questions:Tears, saliva, mucus, and breast milk contain the enzyme _____________ that destroys certain bacteria.
lysozyme
Where is the site of Shigella attachment in the host?
m cells
What carries instructions for making proteins from the nucleus into the cytoplasm?
mRNA
Which of the following can be translated into protein?
mRNA
Transcription produces which of the following?
mRNA, tRNA, and rRNA are all produced by transcription.
The main function of the Krebs cycle during cellular respiration is to ______.
make NADH and FADH2 through redox reactions
Which of the following is not a way that pathogens can avoid destruction by the phagocytes of the host immune system?
make a capsule which is toxic to the phagocyte
What is the host range for rabies?
mammals
A therapeutic index is a ratio between
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
Iatrogenic CJD is transmitted via __________.
medical intervention
_____________ is a type of sexual reproduction that occurs in eukaryotes and results in four genetically unique haploid daughter cells.
meiosis
Based on the symptoms stated, what is the most probable disease that this student has developed?
meningitis
Which of the following terms is likely to describe optimal growing conditions for Streptococcus mutans?
mesophile
Most human pathogens prefer moderate temperatures and therefore are classified as __________.
mesophiles
Which temperature group are most pathogens associated with?
mesophiles
As shown in the animation, the start codon also codes for which amino acid?
methionine
The image shows the result of a certain differential staining method that detects the presence of mycolic acid in a bacterial cell wall. What is the name of the counterstain used in this method?
methylene blue
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
Immersion oil is required to _________.
minimize scattered light when the high-powered lens is used
Antigenic drift results from:
minor changes to HA and NA spikes resulting from frequent mutation of the influenza RNA genome.
Prions are
misfolded proteins which can cause normal versions to also misfold.
Where in a cell is ATP made?
mitochondria
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 agranulocyte has a large horseshoe-shaped nucleus, and matures into either fixed or wandering macrophages?
monocytes
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
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
What is the correct order of the following eight parts of the GI tract?
mouth, pharynx, esophagus, stomach, small intestine, large intestine, rectum, anus
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
A virus that can only infect humans would best be described as having a ______________.
narrow host range
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) ____________.
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 _________________.
naturally occurring antimicrobial compounds
Which of the following would be considered a symptom?
nausea
Which of the following comprises the peripheral nervous system?
nerves
The ________ sense internal and external stimuli, and send out responses in the form of chemical messengers called ________.
neurons; neurotransmitters
A patient who has been hospitalized with uncontrolled muscle spasms has probably been infected with bacteria that secrete a(n)
neurotoxin
Human pathogens grow best between pH 5 and 8, making them ________.
neutralophiles
Which of the following pH classifications make up most of the pathogens we know today?
neutralophiles
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 ___________. The pictures shows two white blood cells among numerous red blood cells.
neutrophils; acute bacterial infections
Although antivenom can save lives, it can also cause what type of reaction in certain patients?
nonautoimmune type III hypersensitivity
This image shows the results of three different bacterial species grown on MacConkey. All three organisms have grown on the media. Which organism(s) is/are gram-positive?
none of the organisms are gram-positive
Tissue necrosis caused by Clostridium perfringens may be distinguished from necrotizing fasciitis in what way?
presence of Gram-positive, endospore forming bacilli in the affected area and emission of foul-smelling gases from the damaged tissue
Which type of phosphorylation mechanism is used to generate ATP in the ETS?
oxidative phosphorylation
Sugar molecules, such as glucose, are _________ during the first steps of energy harvest for a cell.
oxidized
The purpose of the reduced electron carrier coenzymes (such as the NADH and FADH2 that are produced during glycolysis, the intermediate step, and the Krebs cycle) is to be __________.
oxidized at the ETC
Whole cells or viruses are engulfed and imported into a eukaryotic cell via _________.
pagocytosis
What causes warts?
papillomavirus
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
Which of the following is not one of the signs assessed using Amsel's criteria to diagnose bacterial vaginosis?
presence of any type of redness or rash
The ability of certain bacterial cells to take on different cell shapes is known as
pleomorphism
Which of the following diseases cause flu-like symptoms in most people infected, but can cause muscle weakness or paralysis?
polio
What results from the process of translation?
polypeptide
The thymus and bone marrow are considered _________ lymphoid tissue
primary
The thymus and bone marrow are examples of __________ lymphoid tissues and play a role in _________.
primary; maturation of leukocytes
To start DNA replication, the origin of replication is recognized by a collection of factors called the __________.
primosome
What is the most likely etiology (cause) of this disease?
prion
Which of the following acellular agents do not have any genetic material and therefore do not replicate?
prions
Which of the following infectious agents are the most difficult to control with standard autoclaving methods?
prions
The size of most prokaryotes is between:
0.5 and 2.0 μm.
Which of the following numbers on the pH scale represents an extremely acidic solution?
2
Put the stages of binary fission in the correct order: 1. Copied chromosomes separate to opposite ends of the cell. 2. Septum begins to form near the midpoint of the cell. 3. Cell prepares to divide and copies its chromosome. 4. Septum walls off the two daughter cells. 5. Cell reaches a critical size.
3-1-5-2-4
Which of the following indicates calcium's atomic mass?
40.078
Which of the following indicates carbon's atomic number?
6
Aseptic culturing techniques require all of the below except:
A pure culture
Select the false statement.
A pure culture has colonies that exhibit different shapes and coloration.
Which of the following describes primary active transport?
ATP is used to drive transport.
__________ is the preferred microbial media format for isolating individual bacterial colonies.
An agar plate
Which of the following is mismatched?
Atomic nucleus: Contains protons, neutrons, and electrons
Choose the false statement about biofilms.
Biofilms are easily treated using antibiotics.
Choose the false statement about buffers:
Buffers may cause alkalosis.
Which of the following is a molecular formula?
C6H12O6
Which of the following molecules is organic?
C6H12O6
Which of the following is the broadest taxonomic classification?
Domain
Which of the following are short protein structures that help prokaryotes stick to surfaces?
Fimbriae.
Which of the following bacterial structures is used to propel bacteria at high speeds?
Flagella.
Which of the following describes a triglyceride?
Glycerol bonded to three fatty acids.
Which of the following is a carbohydrate substance that encourages bacterial adhesion to host tissues?
Glycocalyx.
Choose the single true statement about biological molecules:
Glycosidic bonds join the simple sugars in a carbohydrate.
Choose the true statement about Gram-negative versus Gram-positive cells.
Gram negative cells are more resistant to penicillin-based drugs than Gram-positive cells.
Acids contribute _________ to an aqueous solution.
H+
Select the single true statement.
Hydrogen bonds do not bind atoms into molecules.
Which of the following would not readily dissolve in water?
Hydrophobic substance
Who was the first person to recommend hand washing to reduce mortality rates?
Ignaz Semmelweis
Which component of the light microscope modulates how much light is aimed at the specimen?
Iris diaphragm
Which of the following describes a Gram-positive cell wall?
It has a thick peptidoglycan layer.
Choose the single false statement about Mg2+ ?
It is an anion.
Which of the following describes phosphotransferase systems?
It often involves group translocation through the use of phosphoenol pyruvate.
Which of Koch's postulates involves isolating an organism from the diseased host and growing it in pure culture?
Koch's second postulate
The experiments that finally disproved spontaneous generation were performed by:
Louis Pasteur
Which of the following is false regarding normal microbiota?
Members of the normal microbiota cannot cause disease.
Which of the following is a description of a symbiotic relationship in which the symbiont is helpful to the host?
Mutualism
Identifying acid-fast bacteria is important in diagnosing the presence of _________species, which include species that cause diseases such as leprosy and tuberculosis.
Mycobacterium
What compound in a bacterial cell wall makes it acid-fast?
Mycolic acid.
Choose the true statement
Osmosis is a passive process.
Which of the following is not an industrial use for microbes?
Production of metal alloys
Choose the single true statement about equilibrium.
Products and reactants form at an equal rate.
Select the single correct pairing of biomolecule and description.
Proteins: Encoded by genes in DNA.
Which of the following is a component of the archaeal cell wall?
Pseudopeptidoglycan.
Which of the following is not a functional group?
R-H
Which type of microscopy uses a beam of electrons to show the surface features of a specimen?
Scanning electron microscopy (SEM)
Which of the following transport mechanisms does not necessarily involve a membrane barrier?
Simple diffusion.
Which of the following is not a benefit of small size to prokaryotes?
Small size allows for greater genetic complexity.
Which of the following is not a part of aseptic technique?
Sterilizing surfaces in an operating room.
Assume you know a cell is acid fast. Which of the following can you most safely conclude?
The organism is Gram-positive.
Which of the following is false regarding the sickle cell trait?
The sickle cell trait is caused by malarial parasite infections.
Which of the following is not a characteristic of archaeal plasma membranes?
They are made of linear fatty acids.
Which of the following is not a reason that acid-fast bacteria are clinically a challenge?
They form endospores that resist heat and sanitizing practices.
Select the false statement about Mycoplasma?
They have a cell wall.
Choose the false statement regarding prokaryotic cell.
They lack organelles.
Which of the following is most likely to be transferred in a chemical reaction?
Valence electron
which of the following is not acid-fast?
Vibrio cholerae
Which of the following agents is considered nonliving?
Viruses
You believe that you have performed a perfect Gram stain on a mixed culture of Gram-positive and Gram-negative bacteria, yet when you observe the cells under the microscope, they all appear pink. What went wrong?
You left the decolorizer on the smear for too long
If a bacterial cell with a damaged cell wall is placed in a hypotonic solution it will ___________.
absorb water from the environment and lyse.
Bacteria that have a rod shape are called _________.
bacilli
Periplasmic flagella are located:
between the plasma membrane and the cell wall.
Most prokaryotic cells reproduce through _________.
binary fission.
Biological macromolecules that follow the general molecular formula (CH2O)n are __________.
carbs
A chemical reaction that creates a more complex molecule and releases water in the process is best described as a(n) __________ reaction.
dehydration synthesis
Prokaryotes tend to be small because they rely on _________ of nutrients.
diffusion
Members of the domain Archaea are distinct from those in the domain Bacteria in that the Archaea members:
don't cause human disease.
A chemical reaction in which one or more components are swapped between molecules is known as a(n) _________ reaction.
exchange
Chlorine usually exists as the anion Cl- because it has __________.
gained an electron.
Na+ and Cl- in table salt are held together by __________ bonds.
ionic
Biological macromolecules that include fats, oils, waxes, and steroids are __________.
lipids
Organisms from the domains Bacteria and Archaea lack:
membrane-bound organelles.
A __________ is formed when two or more atoms of the same or different elements are bonded together.
molecule
The __________ in acid-fast bacterial cell walls retain the carbol fuschin in the Ziehl-Neelsen acid fast staining method.
mycolic acid
An isotope of an element has a different number of ________.
neutrons.
You have counted 38 bacterial colonies on the surface of a petri dish and recorded the number in your lab notebook. This is an example of a(n) __________.
observation
A(n) _________ only causes disease in a weakened host.
opportunistic pathogen
An ability to take on different shapes to enhance survival and/or ability to cause disease is called _______________.
pleomorphism.
The sequence of amino acids that make up a protein are known as the ____________ structure.
primary
A protein's ______________ structure requires the presence of more than one polypeptide chain.
quaternary structure
Adding oil to the slide when using the 100X objective improves the ________ of the image.
resolution
The idea that life comes from nonliving material is known as ___________________.
spontaneous generation
A genetic variant of a bacterium is known as a __________.
strain
A _________ explains how and why something occurs.
theory
If a bacterial cell with an intact cell wall is placed in a hypertonic solution it will____________.
undergo plasmolysis.
Organisms that are adapted to survive in cold temperatures have a higher proportion of __________ in the lipid bilayer.
unsaturated fatty acids
Which nitrogenous base is found in RNA but not DNA?
uracil
The sodium ion is noted as Na+ because it has an overall charge of _______.
+1
Which of the following suffixes would be used to describe a viral family?
-viridae
Most prokaryotes are between ________ in size.
0.5 and 2.0 μm
Refer to the numbered steps in the figure when answering the question. Which step shows an energy investment in the form of ATP?
1 and 3
What is the average net gain of ATP produced in fermentation?
1 to 2 ATP molecules
Place the following events in the correct order as they occur on the lagging strand: 1.Helix unwinding 2.DNA polymerase III builds DNA 3.DNA polymerase I acts 4. ligase glues Okazaki fragments together 5.RNA primase builds RNA primers
1, 5, 2, 3, 4
Spontaneous mutations are estimated to occur in one out of every _______ base pairs.
10^10 (10 billion)
What is the recommended schedule for the first chicken pox vaccine in infants?
12 months of age
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?
13 minutes
What would the generation time be for an organism that goes through 10 generations in 150 minutes?
15 minutes
In what year did Stanley Prusiner discover prions?
1982
How many answers are there to a question in a dichotomous key flowchart?
2
How many net ATPs can be made from one molecule of glucose in glycolysis?
2
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
Put the following steps of protein synthesis in the order that they occur in a eukaryotic cell: 1.Translation ends at a stop codon 2.RNA polymerase transcribes mRNA from DNA 3.Protein sequence is elongated 4.Translation initiates 5. mRNA is processed and travels to a ribosome
2, 5, 4, 3, 1
According to the CDC graph, __________ had one of the highest rates of initial doctor office visits for HPV.
2006
Starting with three cells, how many cells would result from three rounds of replication?
24
Which of the following is the most general classification of an organism?
Domain
Choose the false statement about enzymes.
Enzymes are used up in a reaction.
Why are ehrlichiosis and anaplasmosis of concern?
Incidence of both is increasing.
Which of the following is not part of the epidemiological triangle?
Incidence rate
Endotoxins are also known as
Lipid A
Which of the following vaccines is administered orally?
Rotavirus vaccine
Your initial inoculum was 200 cells. How many cells would be present after 2 hours if the generation time was 30 minutes?
3,200 cells
The 80S ribosome is composed of each of the following except:
30S subunit
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
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
According to the animation, ribosomes move along the mRNA in which direction?
5 to 3
During elongation, how is the RNA synthesized?
5' to 3'
The leading strand of DNA is synthesized in which direction?
5' to 3' in the same direction as helix unwinding
Which direction are phosphodiester bonds of DNA usually built in?
5' → 3'
Place the following events in the correct order as they occur in the lytic cycle: 1Assembly 2Penetration 3Release 4Replication 5Attachment
5, 2, 4, 1, 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
How many codons code for the amino acid arginine?
6
Refer to the numbered steps in the figure when answering the question. Which step is a redox reaction?
6
The Center for Disease Control and Prevention recommended that men infected with Zika virus delay planned pregnancies. What is the recommended length of time for delayed conception for men afflicted with Zika virus?
6 months following symptomatic recovery
Which of the following drugs demonstrates the most effective minimal inhibitory concentration?
9
What is a boil?
A boil is a red lump in the skin that may be warm and painful to the touch. It is a localized accumulation of pus and tissue debris.
Which of the following scenarios would be most likely to lead to graft-versus-host disease?
A bone marrow is transplanted from an older, unaffected sibling to a younger sibling affected with severe combined immunodeficiency.
Which of the following is an example of catabolic and anabolic reactions working together?
A cell breaks down a polysaccharide to produce ATP, which is then used to build a polypeptide molecule.
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
Which of the following would be considered a vector?
A fly carrying disease from fecal matter to food
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.
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
Which of the following does not describe an essential nutrient?
A necessary substance that a microbe makes.
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 patient stops taking his amoxicillin that he was prescribed for strep throat because he felt better after 5 of 10 doses.
Which of the following scenarios would most likely result in Listeria meningitis?
A pregnant woman consumes a sandwich with tainted deli meat and feta (a soft cheese).
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 not a reason Rocky Mountain spotted fever should be diagnosed within the first few days of an infection?
A schizophrenia-like illness or mood disturbances may result.
Choose the false statement.
A stethoscope is classified as critical equipment.
What would happen if the mRNA codon that coded for Cys was mutated in the third position from a U to an A?
A stop codon would be introduced prematurely.
Which of the following could result in a tetanus infection?
A two-inch piece of wood causes a deep puncture in your arm when replacing a board on your deck.
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 energy-rich molecule directly powers cell work?
ATP
Which of the following statements about ATP is false?
ATP can be stored in large amounts in a cell.
Why is ATP required for glycolysis?
ATP makes it easier to break apart glucose into two three-carbon molecules.
Which of the following is the correct mRNA sequence encoded by the DNA sequence: TAC GGT CAC TTC ACT?
AUG CCA GUG AAG UGA
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 1x10^11
Which of the following is not a characteristic of bacterial growth in nature?
Abundant nutrients are regularly present.
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 is useful for identifying Mycobacterium tuberculosis, the bacteria that cause tuberculosis?
Acid-fast stain
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
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.
Acid-fast stain: turns acid-fast cells blue Gram stain: turns Gram-negative cells purple
___________ is caused by a Gram-positive resident, Propionibacterium, which uses sebum as a nutrition source.
Acne
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 is not a type of endocytosis?
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.
In what areas of the world is this infection most prevalent?
Africa and Asia
Which of the following statements is true concerning the life cycle of Giardia lamblia?
After ingestion, a Giardia lamblia cyst hatches into two trophozoites in the small intestine.
When do helper T-cells develop into TH1 or TH2 cells?
After proliferation into a clonal population
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.
What is the best way to prevent the spread of this infection?
All food handlers are required to wash their hands thoroughly after using the restroom.
What is the fate of activated cytotoxic T-cells?
All of the answers are correct
Which of the following are functions of lectins?
All of the answers are correct
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 complement pathways employs properdin?
Alternative pathway
Which of the following is not associated with the DNA helix?
Amino acids
Your patient is an otherwise healthy 40-year old male who presents with high fever, severe abdominal pain, and shaking chills. An abdominal ultrasound confirms the presence of several liver abscesses. The patient notes that the week prior, he had dysentery. The patient is thought to have contracted the pathogen at a Florida waterpark three weeks ago. Based on the patient's clinical presentation and case history, which of the following diseases did your patient most likely contract?
Amoebiasis
Which of the following was the first semisynthetic derivative of penicillin G?
Ampicillin
Which of the following is the product of transcription?
An RNA sequence
Which of the following scenarios is most concerning for development of hemolytic disease of the newborn?
An Rh- mother pregnant with an Rh+ fetus
Choose the true statement about growth factors.
An amino acid may be an example.
A twenty-year old teenage patient presents with intense vaginal itching, burning, and a "cottage cheese-like" discharge. The patient's case history reveals that she was prescribed amoxicillin for treatment of a severe sinus infection. Which of the following treatments should be prescribed for the patient based on disease presentation and the patient's case history?
An antifungal azole drug should be prescribed.
During his research on West Nile virus, Bill learned that this virus is placed within a functional grouping known as arboviruses. What is meant by the term arbovirus?
An arbovirus is an arthropod-borne virus. An arbovirus is maintained in nature through biological transmission
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.
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.
Which general category of drugs is the most selectively toxic?
Antibacterial drug
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
How might a patient who is not being treated with an antibiotic still be exposed to an antibiotic?
Antibiotics can be used in aerosols, thereby entering the environment
Why should antibiotics not be given to a patient with Escherichia coli O157:H7?
Antibiotics do not reduce disease and may precipitate HUS.
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.
_________ was the first scientist to observe bacteria under the microscope.
Antonie van Leeuwenhoek
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 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.
GAU codes for
Aspartic Acid
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
Which of the following steps is not part of lysogenic replication?
Assembly
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
According to the agglutination tests pictured below, what is the blood type of the sample being tested?
B
TH2 cells produce cytokines that activate
B cells
A patient with the antigens A and RH+ would not be able to receive blood from which of the following?
B+
Most hospitals and microbiology teaching laboratories 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 Mycobacterium tuberculosis would be cared for in a __________ facility.
BSL-3
Which of the following organisms is not an opportunistic pathogen?
Bacillus anthracis
All of the following spore-forming bacterial species cause disease except:
Bacillus subtilis.
What type of nosocomial infection is likely to arise from intravenous catheterizations?
Bacteremia
How is bacterial translation different from eukaryotic translation?
Bacteria can begin translation before transcription has terminated.
Why is visualization not sufficient to properly identify bacteria?
Bacteria have a limited set of shapes and many unrelated bacteria share the same shape.
Why did Alexander Fleming suspect he could get penicillin from a species of mold?
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 best describes how bacterial growth in nature is different from growth in a laboratory setting?
Bacteria tend to grow as a mixture of species in biofilms in nature.
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.
Which is the most effective method for culturing bacteriophages?
Bacterial culture on solid agar or in liquid broth
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.
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.
Stool is rich in which of the following organisms?
Bacteriodes
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 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
What is the function of the CD8 receptor?
Bind to MHC molecules
What is the function of single-strand binding proteins?
Bind to the DNA strands near the replication fork to keep them separated
Which of the following is not a role of the eukaryotic glycocalyx?
Biofilm production.
Which of the following is an incorrect statement about biofilms?
Biofilms are composed of planktonic bacteria.
Which of the following explains the mechanism of dental cavity formation?
Biofilms on the surface of the teeth ferment sugars (especially sucrose), and the resulting acid degrades the tooth enamel and damages dentin.
Which of the following is not a mechanism of an antiviral drug?
Blocking viral ribosomes
Which of the following is not recommended for culturing anaerobic bacteria?
Blood agar.
__________ can eliminate pathogenic bacteria, protozoans, and viruses.
Boiling
Erythema migrans often develops as a result of what infection?
Borrelia burgdorferi
Both Vibrio cholerae and Salmonella typhi are capable of causing disease inside of otherwise healthy individuals. The ID50 of V. cholerae is 1,000,000 cells, while the ID50 of S. typhi is 10,000 cells. Based on this information, which of the following statements is true?
Both V. cholerae and S. typhi are pathogenic, but S. typhi is more virulent than V. cholerae.
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.
Choose the mismatched pair regarding media formats.
Broth format: used for colony isolation.
Why are diabetics at risk for wound infections by anaerobic bacteria like Clostridium perfringens?
C. perfringens colonizes unhealthy tissues that do not receive enough oxygen, and diabetics have difficulty transporting oxygen to body tissues, especially in the extremities.
Which complement protein is used as an opsonin?
C3b
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 event happens first during cytotoxic T-cell activation?
CD8 binds to MHC molecules of infected cells
Genes can be silenced by a process called DNA methylation. Which of the following compounds is a methyl group?
CH3
Which of the following correctly describes the molecular formula for methane, which is comprised of one carbon atom and four hydrogen atoms?
CH4
Which of the following is an organic molecule?
CH4
What is the most likely cause of this couple's disease?
Campylobacter jejuni
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
How can capsules enable bacteria to evade the immune system?
Capsules block the complement biding sites on the surface of the pathogen.
Which of the biomolecules is incorrectly matched with its building block?
Carbohydrate: Polysaccharide
Of the following, which does NOT occur in the Krebs cycle?
Carbon molecules are reduced and the electron carrier molecules are oxidized.
Which protective mechanism of the eye is incorrectly matched with its description?
Conjunctiva: Transparent layer which protects the iris
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.
Carbon's atomic number is 6. One carbon atom contains 6 protons and 6 neutrons.
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
Which of the following can release histamines?
Cells from damaged tissues and the complement pathway
Which organelle builds microtubules?
Centrosome
Which of the following describes conidiospores?
Chains of spores not enclosed in a sac.
__________ 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
What complement result involves the use of phagocytes?
Chemotaxis and opsonization
_________ is to fungal cell walls as _________ is to bacterial cell walls.
Chitin; peptidoglycan
What microbial agent would be associated with the symptoms seen in this mother-to-be?
Chlamydia trachomatis
Choose the false statement.
Chlorine treatment is sufficient for eliminating protozoans from drinking water.
What molecule is used to capture light energy?
Chlorophyll
Which of the following describes the steps in binary fission?
Chromosome replication, cell pinches off in the middle; migration of cell components to each end of the cell; septum formation.
Which of the following occurs in binary fission, budding, and spore formation?
Chromosome replication.
Which of the following statements accurately describes a chronic Hepatitis B viral infection?
Chronic Hepatitis B viral infections can promote cirrhosis and hepatocellular carcinomas.
A young graduate student studying deer habitats in the Northeastern United States presents with fever, a headache, and extreme fatigue. You believe that the patient may have a viral infection, and send her home without any medication. Five days later, the patient is readmitted and presents with a bulls-eye rash. If you do not treat the infection with the recommended antimicrobial therapy, which of the following complications may develop?
Chronic arthritis, neurological problems, irregular heartbeat, and myocarditis
Which of the following word pairs describing chronic and latent viral infections is mismatched?
Chronic infections: distinguished by flare-ups triggered by stress
Which of the following does not describe a eukaryote?
Circular DNA
Which of the following is not a viral genome arrangement?
Circular RNA
Why did the man's sexual partners believe they were not infected with a STD?
Clinical signs and symptoms in females are often not detectable, especially early in the infection.
Which of the following is the most common healthcare-acquired infection (HAIs)?
Clostridium difficile infections
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
The main causative agent of gas gangrene is ___________.
Clostridium perfringens
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 coenzymes is NOT involved in redox reactions as an electron carrier coenzyme?
CoA
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
Which of the following would not reduce microbiological clinical sample analysis errors?
Collecting patient samples in hospital settings.
After ingesting contaminated spinach, your patient presents with fever, jaundice, severe abdominal pains, and hemorrhagic diarrhea. You believe that the patient has contracted Enterohemorrhagic Escherichia coli. Which of the following laboratory techniques would be the most useful for identification of the foodborne pathogen?
Cultural analysis of stool sample on sorbitol-MacConkey (SMAC) agar
Which of the following is a bacterium that performs oxygenic photosynthesis?
Cyanobacteria
Which of the following terms is best defined as an inflammation of the bladder?
Cystitis
Which type of cell directly attacks infected cells?
Cytotoxic T-cells
HIV directly infects T-cells. Why is this problematic for cell-mediated immunity?
Cytotoxic T-cells begin to attack the virally infected T-cells, reducing the number of T-cells in the body.
Which of the following molecules can be recycled to produce purines and pyrimidines?
DNA
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.
During DNA replication, which enzyme is involved in proofreading to prevent the incorrect matching of nucleotides?
DNA polymerase
RNA primers are removed from the leading and lagging strand by __________.
DNA polymerase I
In DNA replication, what is the main enzyme responsible for adding complementary nucleotides to the daughter strand while reading the parent strand?
DNA polymerase III
Which enzyme is the main contributor to the development of spontaneous mutations?
DNA polymerase III
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
The Endosymbiotic theory describes the evolution of eukaryotes occurred through the merging of each of the following except:
DNA virus
All of the following explain why viral genomes evolve rapidly except:
DNA viruses have a high mutation rate.
Which of the following macromolecules is incorrectly paired with its building blocks?
DNA: nicotinic acids
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
Why is Daniel underweight?
Daniel is not eating much, because it hurts to chew and swallow.
Which term is correctly paired with its definition?
Decontamination: includes sterilization and disinfection measures
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?
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.
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
Which of the following provides the best definition for the term dysentery?
Diarrhea accompanied by pain, blood, and/or mucus
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.
Your patient, who is in an extended hospital stay, presents with fever, chills, hypotension, tachycardia, and mental confusion. Bloodwork reveals thrombocytosis, elevated creatinine levels, and elevated lactic acid levels, indicative of sepsis. Blood culture on a Sabouraud dextrose agar plate reveals an abundance of yeast. Which of the following is the most likely mechanism through which the patient contracted this disease?
Direct contact with a contaminated venous catheter
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
Choose the false statement about bioremediation.
Dispersants are added so that the remediating microbes can grow.
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.
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
Which of the following is not an example of a virulence factor?
Dysbiosis
Which of the following is a correctly written version of a scientific name?
E. coli
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 capabilitie
E. coli can funnel intermediates from glycolysis, the intermediate step, and the Krebs cycle to synthesize amino acids, fatty acids, glycerol, and nucleotides.
All of the following are limitations of ELISA and agglutination assays except:
ELISA and agglutination assays lack specificity.
Which of the following diagnostic tests paired with their descriptions is mismatched?
ELISA: detects antibodies or antigens with a precipitation reaction
Which of the following eukaryotic organelles plays an essential role in protein and lipid production in the cell?
ER
What makes agglutination by antibodies possible?
Each antibody has at least two antigen-binding sites.
Which is not an example of virulence as an evolving property?
Each of these is an example of virulence as an evolving property.
How can a sufficient humoral immune response occur if a plasma cell only lives for a few days?
Each plasma cell can produce up to 2000 antibodies every second.
All of the following viruses exhibit narrow tropism except ____________.
Ebola virus
Which of the following may help in controlling outbreaks of Lassa virus?
Effective rodent control and storing food in rodent-proof containers
Choose the false statement about electrolytes:
Electrolyte imbalances are difficult to treat.
Which of the following does not rely on isotopes?
Electrolyte therapies
___________ 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 is the most effective method for culturing viruses used in the development of the influenza and mumps vaccine?
Embryonated eggs
The brain tissue of the birds indicated the possibility of encephalitis. What is encephalitis, and why should this type of infection cause concern among health care professionals?
Encephalitis is an inflammation of the brain tissue. It is a concern to health care professionals because an infection in the brain means the virus has breached protective measures.
Substances from the exterior environment enter eukaryotes through:
Endocytosis
Which organelle is connected to the nuclear membrane?
Endoplasmic reticulum
What bacterial structures are revealed through the use of heated malachite green and safranin?
Endospores
Which of the following is true about endospores?
Endospores are highly resistant to environmental stress.
Which is not a reason why endospore-forming bacteria pose challenges in healthcare settings?
Endospores are only produced by Gram-positive organisms.
Which of the following statements is incorrect about endospores?
Endospores are reproductive structures.
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.
Which species of amoeba would be considered the causes this patient's disease?
Entamoeba histolytica
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
Which of the following are fecal coliforms?
Enterobacter Klebsiella Serratia
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
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?
Fluconazole
How does immunofluorescence microscopy detect rabies in 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 statements accurately compares foodborne infections to food poisoning?
Foodborne infections are due to pathogen establishment, whereas food poisoning is a toxigenic infection.
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
How does cytolysis occur via the complement pathway?
Formation of the MAC in invading cells, killing them
Each of the following describes eukaryotic cilia except:
Found in both prokaryotes and eukaryotes.
Which of the following statements is true regarding hand washing?
Frequent and proper hand washing should be routinely done by patients and by healthcare workers, both prior to and after interaction.
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.
Mitosis is characterized by
Genetically identical cells
Which of the following is characterized as a Mastigophora, or "flagellated protozoan"?
Giardia intestinalis
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 do not have a beta-lactam ring, so they are not susceptible to beta-lactamases.
Which of the following is not a type I hypersensitivity reaction?
Goodpasture syndrome
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
The first question in this dichotomous key addresses
Gram stain differences.
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
Which of the following best describes the Enterobacteriaceae group (enteric bacteria)?
Gram-negative bacillus found in many locations including animal intestines
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 of the following statements correctly describes endotoxins?
Gram-negative bacteria mainly release endotoxin when they die, although a small amount can be released as the bacteria divide.
Septic shock is typically associated with
Gram-negative infections.
_____________ bacteria lack an outer membrane, have a thick layer of peptidoglycan, contain teichoic acid, and lack mycolic acid.
Gram-positive
Which molecule triggers apoptosis?
Granzyme
Your patient presents with oral lesions. The patient states that her mouth had a tingly sensation for 3 days before fluid-filled blisters appeared on the lips. Which of the following pathogens is the most likely etiological agent?
Herpes Simplex-1 Virus
Which of the following DNA virus families includes viruses that cause oral herpes, genital herpes, and chickenpox?
Herpesviridae
Which of the following is the family name for the HHV-1 virus?
Herpesviridae
The main function of the nucleus is __________.
Houses the cell's DNA; serves as the cell's command center.
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 is the species name of HHV-1?
Human herpesvirus-1 or Herpes simplex virus 1.
Which of the following viruses causes a chronic infection?
Human immunodeficiency virus
Which of the following is oncogenic?
Human papilloma viruses
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 independently synthesize folic acid (the target of sulfa drugs), but acquire it from their diet.
Which of the following enzymes breaks down the "glue" that holds cells together?
Hyaluronidase
____________ 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
Tubular structures that form the structure of most fungi are __________.
Hyphae
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.
What was the best treatment for this patient once he had gone to the ER?
IV fluids, sedation, and respiratory support
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
Health care providers determine the specific allergen that is generating symptoms by using a blood test to look at ________ levels.
IgE
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
Choose the false statement.
IgG binds to the surface of mast cells and basophils.
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 class of antibody is the first produced during the primary response?
IgM
_________can exist as either a monomer or a snowflake-shaped pentamer and is central to _________.
IgM; agglutination and precipitation reactions
What is the recommended course of treatment when a rabid animal bites a person?
Immediately wash the wound with soap and water, inject the bite area with rabies immunoglobulin, and begin a series of four rabies vaccine injections.
What is graft-versus-host disease?
Immune system cells in transplanted bone marrow attack the body of its new host.
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.
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.
Choose the true statement about a bacterial colony?
In theory a colony derives from a single cell.
Which of the following statements is true concerning a patient with an acute HIV infection?
Inability to detect HIV antibody in the patient's serum
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. A dark image is contrasted on a bright background. Bright field microscopy is the most simple and common form of microscopy.
Which of the following is an incorrect statement about aseptic technique?
It is a sterile technique.
Which of the following statements about fermentation is true?
It is an alternative way to return electron carriers to their oxidized state.
Choose the false statement about the eukaryotic cytoskeleton.
It is an extension of the glycocalyx.
Which of the following is false about the tropical disease African sleeping sickness?
It is carried by a blood-sucking mosquito from host to host.
What is the fate of the prophage during the lysogenic stage?
It is copied every time the host DNA replicates.
Which of the following is not a characteristic of the prokaryotic nucleoid region?
It is enclosed in a membrane.
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.
Which statement is not true about leishmaniasis?
It is preventable by a vaccine which is recommended for travelers to endemic areas.
What is meant by light rays being divergent?
It is spreading out
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.
What does halophilic mean?
It means the organism is "salt-loving."
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.
Choose the false statement about binary fission.
It produces daughter cells that are genetically unique from one another
Some microorganisms, such as E. coli and B. subtilis, can move glucose 6-phosphate into the pentose phosphate pathway instead of glycolysis. Which of the following statements describes an advantage of this pathway?
It provides an alternative pathway for creating nucleotides and amino acids.
What is the fate of the NAD+ newly regenerated by fermentation?
It returns to glycolysis to pick up more electrons.
What is the role of pyruvic acid in fermentation?
It takes the electrons from NADH, oxidizing it back into NAD+.
Which of the following statements about the lagging strand is false?
It uses only one molecule of DNA polymerase I.
How would the results be different if this organism was Salmonella?
It would produce hydrogen sulfide.
What is the purpose of an anticodon?
It's a region on a tRNA that binds to a complementary codon on mRNA to ensure the proper amino acid is added to a growing protein.
Which of the following is true about antimicrobial peptides?
It's rare for microbes to develop resistance to AMPs.
An inflammatory response would result from which of the following?
Jellyfish sting
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.
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 is an acid produced by fermentation?
Lactic acid and propionic acid
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.
Which of the following word pairs describing chronic and latent viral infections is mismatched?
Latent infections: run their course and are cleared by the host immune system
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
What is the role of lenses in microscopy?
Lenses focus either light or electrons to create a magnified image of a specimen.
Which of the following is one of the categories of the second-line defenses?
Leukocytes
Which statement does not apply to pneumocystis pneumonia and its causative organism, Pneumocystis jirovecii?
Like all other pathogenic fungi, the reservoir is soil.
Which of the following is the best mode of controlling the spread of West Nile infections?
Limit exposure to mosquitoes to prevent the transmission of West Nile virus.
Which of the following is not one of the three main ways microbes evade antimicrobial drugs?
Limit production of peptidoglycan
A physician swabs an inflammed raised area on patient's arm for testing to determine if Staphylococcus aureus is the cause of the infection. The test should confirm the presence of S. aureus, but also rule out other species found in the patient's normal skin microbiota. What selective and differential media would be the best choice to use to determine an S. aureus infection?
MSA
The typical composition of MSA is as follows: 5.0 g/L enzymatic digest of casein 5.0 g/L enzymatic digest of animal tissue 1.0 g/L beef extract 10.0 g/L D-mannitol 75.0 g/L sodium chloride 0.025 g/L phenol red 15.0 g/L agar pH 7.4 ± 0.2 at 25°C Whcih of the following statements about the media composition is FALSE?
MSA is a chemically defined media
Which of the following media is used to isolate Gram-negative organisms?
MacConkey agar plate
Urinary tract infections are commonly caused by Staphylococcus saprophyticus and Escherichia coli, less commonly caused by Proteus mirabilis. You have a mixed culture of these pathogens, which you inoculate onto both MacConkey agar and nutrient agar, and then you incubate the plates at optimal growth conditions. On the MacConkey agar, E. coli appears pink, P. mirabilis appears colorless, and S. saprophyticus does not grow. All three microorganisms appear cream on the nutrient agar plate. What is the best explanation for this data?
MacConkey is both a differential and a selective medium.
Which of the following antimicrobials does not match its potential shortcomings?
Macrolides: This narrow-spectrum drug must be administered parenterally.
Which of the cells listed below can present antigens on Class II MHC proteins?
Macrophages
________ media would be most effective for selecting for Staphylococcus aureus growth.
Mannitol-Salt Agar (MSA)
In terms of personal health, why should vegetarians still care about the misuse of antibiotics in livestock?
Manure-contaminated water and manure-based fertilizers introduce resistant bacteria into the food chain.
Which of the following most accurately describes icosahedral viruses?
May appear spherical, but are three-dimensional polygons
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
Which cells are involved in a secondary response?
Memory B cells and plasma cells
Which of the following is false about toxoplasmosis?
Meningitis results in a majority of patients since there are currently no treatment options.
Which of the following antimicrobial drugs can be inactivated by beta-lactamase?
Meropenem
What does the term mesophile mean?
Mesophiles grow well at body temperature.
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 organisms grow best in low levels of oxygen?
Microaerophiles.
Which of the following is not a characteristic of prokaryotic flagellum?
Microtubules sprout from a centriole.
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
The organelle involved with making amino acids and vitamins, regulating cell division, and carrying out apoptosis is the __________.
Mitochondria
Where are 70S ribosomes found in eukaryotic cells?
Mitochondria and chloroplasts
Which of the following provides supporting evidence that mitochondria and chloroplasts may have once been free-living prokaryotes?
Mitochondria and chloroplasts contain 70S ribosomes.
What are leukocidins?
Molecules that are capable of destroying phagocytes
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.
Choose the false statement.
Most viral disease require treatment.
During a pertussis infection, the pathogenic bacterium Bordatella pertussis produces tracheal cytotoxin, which destroys cilia. Which of the following would most likely result from ciliary destruction?
Mucus would accumulate in the respiratory tract.
How long does it take for the daughter cells to initiate or start the next round of replication?
No time is required -- they are ready to divide immediately after DNA replication and separation of the daughter cells is complete if conditions are right.
Is this disease contagious?
No, the disease is not contagious.
Is it critical to determine the fungal agent or agents contributing to this case? Why or why not?
No. The treatment would be the same.
__________ uses ultraviolet light to sanitize drinking water and disinfect surfaces in operating rooms.
Non-ionizing radiation
Why would a body cell that is not a phagocyte need to present antigens?
Non-phagocytic body cells can become infected with a virus.
Which of the following is a characteristic of roundworms?
Non-segmented, elongated, cylindrical.
How do normal prion proteins (PrP) differ from the infectious prion proteins?
Normal PrP have alpha-helices; infectious PrP have beta-pleated sheets.
All of the following are common to both prokaryotes and eukaryotes except:
Nucleus
The nucleolus, chromatin, and nucleoplasm are found in the __________.
Nucleus
Why are most prokaryotic cells small?
Nutrient diffusion is most efficient for smaller cells.
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.
Where are MHC molecules located on a cell?
On the surface of the cell
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.
Which of the following statements concerning the life cycle of Chlamydia trachomatis is correct?
Once inside the body, the Chlamydia trachomatis reticulate body replicates before converting back to the elementary body.
Which of the following statements regarding polio vaccines is true?
One disadvantage of the oral polio vaccine is that immunocompromised individuals can develop illness from the attenuated virus and, in rare circumstances, develop paralytic polio.
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.
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?
Orally
Which of the following is the highest taxon for viruses?
Order
How can Organism "A" grow if it cannot ferment the carbohydrate contained in EMB media?
Organism "A" is metabolizing other nutrients contained in EMB, which do not cause acidic by-products
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.
What do the results of organism A depicted in the image indicate?
Organism A is gram-negative, but doesn't ferment lactose
Which of the following RNA virus families includes the virus that causes influenza?
Orthomyxoviridae
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
What is the final electron acceptor in aerobic cellular respiration?
Oxygen
Where would one find an uncharged tRNA molecule in a ribosome?
P and E sites
During the initiation step of translation, the fMet charged tRNA assembles in which site of the ribosome?
P site
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
Genital warts are caused by __________.
Papillomaviridae
Which of the following DNA virus families includes the viruses that cause warts and cervical cancer in humans?
Papillomaviridae
Which organelle is associated with protein modification?
Rough Endoplasmic Reticulum
A rapid Strep test is often used in the clinic to determine whether a patient is infected with Streptococcus. After swabbing the patient's throat, the sample is mixed with specified reagents and then applied to a diagnostic strip. As the sample moves up the strip, various lines will appear or not appear, depending on the reaction. The "C" line is the positive control-it should always appear. The "T" line is the test-it should only appear if the result is positive. Two samples come into the clinic lab, and the following results are obtained. How would you interpret these results?
Patient 1 is positive for Strep throat; Patient 2's results are inconclusive and must be redone.
When is the human T lymphotropic virus typically detected in a patient?
Patient develops cancer or donates blood.
Which of the following does not describe naked animal virus replication?
Penetration through membrane fusion
After a lytic bacteriophage attaches to a bacterium, what is the correct order of the next steps in the lytic replication cycle?
Penetration, replication, assembly, release
Which of the following is the correct sequence of animal virus replication after attachment?
Penetration, uncoating, replication, assembly, release
The following are concepts that relate to animal viruses. Choose the mismatched pairing.
Penetration: genetic material injected into the cell
Which type of bond links amino acids together to form a protein's primary structure?
Peptide bonds
________ is characterized by tender, swollen gums with a bright red or purplish coloration; the gums may also pull away from teeth, and bad breath and tooth loss are also frequent manifestations.
Periodontal disease
Which of the following devices is most commonly used for manual cell counting?
Petroff-Hausser chamber.
Which of the following best describes the role of mucosa-associated lymphoid tissue (MALT)?
Phagocytic protection from pathogens and mediation of immune responses
Which of the following is also known as "cell eating"?
Phagocytosis
Which of the following is not a key antibody function?
Phagocytosis
Which component of adenosine triphosphate (ATP) is responsible for releasing energy to fuel anabolic reactions?
Phosphate
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
Choose the true statement about phototrophs.
Phototrophs use light for energy.
Which of the following RNA virus families includes the virus that causes polio?
Picornaviridae
Which of the following processes means "cell drinking"?
Pinocytosis
You are tending to your preschool-aged patient who presents with excessive anal itching. The child's mother notes that the child woke several times during the night due to anal irritation. Gastrointestinal symptoms are absent. You recommend performing a tape test on the child. Which of the following diseases is the pediatric patient most likely afflicted with?
Pinworm
Which of the following body sites would least likely contain a biofilm?
Placenta
Which of the following eukaryotic kingdoms does not contain organisms that are pathogenic to humans?
Plantae
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
What is produced by the process of clonal expansion?
Plasma cells and memory B cells
What is the role of plasma cells in humoral immunity?
Plasma cells produce antibodies.
Which of the following statements is NOT a characteristic of plasmids?
Plasmids are part of the cell's chromosome.
Which of the following techniques is the best way to directly count viable cells?
Plate counts
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.
Your 3-year-old patient presents to you with high fever, shaking chills, cough, chest pain, and shortness of breath. The patient's mother stated that symptoms began suddenly last night. The patient is up to date on all vaccinations. Based on this information, which of the following diseases did your patient most likely contract?
Pneumococcal pneumonia
How does Helicobacter pylori cause stomach ulcers?
Polar flagella help bacteria burrow into mucosal lining to escape stomach acid, where enzymes decrease the acidity around them, and they release a toxin to kill host cells.
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.
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 paralyzes the parasite, allowing it to detach from host tissues.
What carbon molecules remain at the end of glycolysis?
Pyruvic acid
Which of the following is a drug used to treat malaria and gives tonic water its characteristic bitter taste?
Quinine
The picture shows the amino acid tryptophan. The highlighted group in green is also known as the _________.
R group
Which of the following functional groups is matched with its correct name?
R-OH: hydroxyl group
Primase lays down a short piece of __________ as a primer to start DNA replication.
RNA
Which of the following molecules is a defining characteristic of a ribozyme?
RNA
According to the animation, which of the following makes mRNA from the information stored in a DNA template?
RNA polymerase
What is the main enzyme required for transcription of a gene?
RNA polymerase
Which of the following is not an enzyme involved in DNA replication?
RNA polymerase
The role of transcription factors is to signal __________.
RNA polymerase to the promoter region of the intended gene to be transcribed
RNA viruses are able to mutate more rapidly than DNA viruses because _______________.
RNA polymerases do not have proofreading capabilities
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
The binding of a ligand to a receptor, which induces the formation of a clathrin-coated pit, is the first step of _________.
Receptor-mediated endocytosis
Which of the following is not a subunit vaccine?
Recombinant vector vaccine
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
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 does not describe enveloped virus replication?
Release through host cell rupture
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 (HIV-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 patient's 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 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.
Which of the following diseases is incorrectly matched with its characteristics?
Roseola: rare childhood infection that tends to present without a fever
Which of the following is not a characteristic of the eukaryotic flagellum?
Rotary motion
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 fluoresced red. Taken together, these results indicate that:
SASH1 is underexpressed in breast cancer patients, whereas HER2 is overexpressed is breast cancer patients.
What is the etiologic agent of typhoid?
Salmonella
Eating peanut butter, cantaloupe, chicken products, seafood, spinach, or handling a pet turtle are all sources of infection for which of the following bacteria?
Salmonella enterica serotype Enteritidis
Which of the following is incorrectly matched?
Salt: Formed by the combination of hydrogen ions (H+) and hydroxide ions (OH-)
Which of the following is a genus of fluke?
Schistosoma
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
Which of the following is not a viral genome arrangement?
Segmented DNA
__________ media are best described as singling out bacteria with specific properties by encouraging the growth of certain bacteria while suppressing the growth of others.
Selective
Which of the following is mismatched?
Selective media: Specialized media that allow us to visually distinguish one microbe from another based on how they look when grown.
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 describes hyphae with divisions between each cell?
Septate
Siderophores such as enterobactin promote virulence through which mechanism?
Sequesters iron from the host
Information located in the exercise, "Think Clinically: Be S.M.A.R.T. About Cases- Cholera", stated that before it was determined that Vibrio cholerae was the causative agent of cholera, it was theorized that the stench of bilge (sewage) water caused the disease to spread. We now know the miasma "harmful air" theory is wrong, but discovered that proper sewage management reduces the incidence of disease. How did proper sewage management help reduce cholera cases, if not by reducing the stench?
Sewage management led to decreased incidence of human feces in drinking water.
__________ are complexes that remove iron from transferrin for their own use.
Siderophores
How is simple diffusion different from other types of passive transport?
Simple diffusion does not require a permease.
Choose the false statement.
Single-stranded DNA (ssDNA) viruses use RNA-dependent RNA polymerases to build mRNA.
Which of the following characteristics of a catheter should be considered, to help minimize the spread of nosocomial infections?
Single-use
Which of the following diseases was eradicated after a successful vaccination program?
Smallpox
The kingdom Protista is sometimes referred to as the "catchall kingdom." All of the following describe characteristics of organisms in the kingdom of Protista except:
Some only utilize RNA.
Which of the following indirect methods of enumerating bacteria measures the turbidity of a sample?
Spectrophotometer.
Which of the following is an asexual fungal spore?
Sporangiospores
Gamogony is the sexual phase of reproduction of ________.
Spore-forming protozoans
Your patient from Zambia presents with shivering, fever, sweats, hypotension, headaches, body aches, fatigue, nausea, and vomiting. You presumptively diagnose the patient with malaria and then perform a liver biopsy. Which of the following forms of the malarial parasite would you most likely observe within the patient's liver biopsy?
Sporozoites within infected liver cells, and merozoites emerging from affected, lysed liver cells
A catalase test would be helpful to distiguish which of the following organisms?
Staphylococcus and Streptococcus species
Which of the following is one of the most common agents to cause endocarditis?
Staphylococcus aureus
Which organism is most likely to be responsible for the boils?
Staphylococcus aureus
Which of the following is not an example of intrinsic resistance of a bacterium to an antimicrobial drug?
Staphylococcus aureus (VRSA) strains with altered cell wall-building enzymes
Which of the following could be used as evidence for spontaneous generation?
Uncovered meat will give rise to maggots.
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.
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 bacteria has an affinity for the heart valves?
Streptococcus mutans
Most bacterial meningitis cases in the United States are pneumococcal meningitis, caused by which of the following bacteria?
Streptococcus pneumoniae
Infections with these symptoms are generally caused by which of the following pathogens?
Streptococcus pyogenes
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
How are superantigens different from other types of exotoxins?
Superantigens cause an overstimulation of the host immune system.
A patient's preliminary diagnosis, as well as the stage and site of infection, affect how and when a representative sample is obtained for microbiological analysis. 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
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
An antigen that is potent enough to activate a B cell on its own is known as
T-independent antigens.
Which T cell class is incorrectly matched with its description?
TC: attack other T cells during self-tolerance screening
Which receptor on the helper T-cell recognizes the specific antigen from an antigen-presenting cell?
TCR
Which of the following uses cows as the intermediate host?
Taenia saginata
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.
Gumma lesions on the skin and bones, heart damage, and neurological symptoms are characteristic of which stage of syphilis?
Tertiary syphilis
Which of the following bacterial pathogenicity factors is not the result of phage conversion?
Tetanus toxin
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?
Tetracycline
Natural killer cells are activated by
Th1 cells
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 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.
What is a drawback of live attenuated vaccines?
The agents present in this type of vaccine could cause disease in an immune-compromised host.
If a person turns their ankle, how would one determine if damage to the tissue in the ankle has occurred?
The ankle is red, swollen, and warm to the touch.
Which of the following most accurately describes how a pathogenic bacterium might be affected by antibodies?
The antibodies may block proteins necessary for binding the pathogen to the host, may opsonize the bacterium, or may agglutinate bacteria.
How does the ribosome know if the entering charged tRNA is correct?
The anticodon on the tRNA base pairs to the codon on the mRNA.
How does a capsule help certain bacteria evade detection by the immune system?
The capsule is composed of polysaccharides that are similar to those found in the host; thus, the immune system does not recognize it as foreign.
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.
What enables the copied chromosomes to separate during binary fission?
The chromosomes are attached to different parts of cell membrane, which elongates and thus separates the chromosomes.
Which of the complement pathways was discovered first?
The classical pathway
Why is no energy required in passive transport?
The concentration gradient drives the movement.
This disease is spread from person to person only. How contagious a disease is it considered to be?
The disease is rarely transmitted from person to person.
How is fermentation of lactose detected?
The drop in pH turns the indicator dye yellow.
Which of the following is false of Shigella infections?
The elderly are most likely to become infected.
Which organelle assists directly with the presentation of MHC-I antigens?
The endoplasmic reticulum
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.
How is the lytic cycle different from the lysogenic cycle with respect to the infected host cell?
The host cell dies during the lytic stage.
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.
Why is hyphal morphology (as opposed to a unicellular morphology) necessary for symptomatic vaginal candidiasis to develop?
The hyphal form produces proteases that cause cellular damage which results in inflammation.
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 false about the lepromatous form of leprosy?
The lepromatous form is more common than the milder tuberculoid form.
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.
What test result indicates that the unknown can utilize citrate as its sole carbon source?
The medium turns blue.
Which of the following correctly describes Infectious Dose-50 (ID50)?
The more infectious the pathogen is, the lower the ID50.
Why are the beta-pleated multimers of PrP potentially pathogenic?
The multimers are more stable and resistant to protease.
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
In a typical brightfield microscope (seen in the animation), at which point does magnification begin?
The objective lens
Based on this graph, what is the best conclusion you can make about the microbe being analyzed?
The optimal pH is 4
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.
What would be a drawback when using the API Profile System?
The organism may not grow outside its original environment.
Which of the following about Naegleria fowleri is true?
The organism prefers warm stagnant waters.
Which of the following is not one of the four postulates of disease developed by Koch?
The organism should be present in mixed culture.
Which of the following is not a consideration when collecting a clinical sample from a patient?
The organism's Gram property
What would happen if the septum did not form during binary fission?
The parent cell would now have two copies of the chromosome.
Which of the following is not a property used to group viruses?
Unicellularity versus multicellularity
Your patient presents with fever, body aches, rash, vomiting, and nausea. A presumptive diagnosis of dengue fever is made. Assuming that the diagnosis is accurate, which of the following statements is also true concerning this patient?
The patient should be monitored for anemia and be kept hydrated.
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.
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 is an example of vehicle disease transmission?
The presence of Listeria on undercooked chicken served for dinner
Which of the following is a trait unique to photosynthetic eukaryotes?
The presence of chloroplasts
Which of the following statements about the primosome is false?
The primosome includes RNA polymerase to build the protein.
Where does the name "scrapie" come from?
The prion disorder causes infected sheep to scrape against objects until their skin is raw.
What is apoptosis?
The process of programmed cell death.
Which of the following best characterizes clonal selection?
The production of identical B cells producing the same antibody
Which of the following is a feature true for the adaptive immune response only?
The response is tailored to a specific antigen.
How is the secondary response different from the primary response in terms of antibody concentration in the blood?
The secondary response is faster and produces more antibodies than the primary response.
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.
Which of the following statements help to explain the pathogenesis of human transmissible spongiform encephalopathy?
The shape of normal host PrpC protein is altered by abnormal PrpSc protein, transforming it into infectious PrpSc protein.
Choose the false statement(s) about the simple staining technique. To be marked correct, you'll need to select all false statements, as there may be more than one correct answer.
The simple staining method uses a single acidic dye that stains the slide background.
If mosquitoes are the mode of transmission for West Nile virus, why did the students in Bill's virology class focus on finding the virus in the dead birds rather than collecting mosquitoes to examine?
The students tried to isolate and identify West Nile virus from birds because they are an amplifying host for the virus, making it more likely that the virus can be isolated from these animals.
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.
Why should the actor worry about the spread of the injected Botox from the forehead to other parts of the body or face?
The toxin spreading to other areas of the body would inhibit muscle contractions required for normal daily activities.
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
Which is not an innate protection of the female reproductive tract?
The vaginal lining contains ciliate cells which trap and expel bacteria from the tract.
How do arboviruses cause nervous system infections?
The virus invades and destroys the blood vessel cells that form the blood-brain barrier.
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.
What would be the fate of a lytic bacteriophage if the host cell died prior to the assembly stage?
The virus would not be able to infect new hosts.
How does a patient typically become infected with hookworms?
The worm penetrates the skin when the patient walks outside barefoot.
How is Streptococcus pneumoniae able to avoid destruction by a phagocyte?
Their capsules make them "slippery" to phagocytes.
Which of the following viral features does not contribute to their classification as nonliving?
Their extremely small size
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 invasive procedures likely to increase the risk of nosocomial infections?
These procedures allow microbes from the skin to enter the bloodstream of the patient
Listeria monocytogenes is an intracellular bacterial pathogen that replicates within macrophages. Secretion of listeriolysin O and phospholipase helps the pathogen to escape phagolysosome formation following internalization by the host cell. In this example, listeriolysin O and phospholipase A perform which essential function?
These virulence factors help the pathogen evade host defenses.
What direct effect do histamines and leukotrienes have on capillaries?
They allow capillary walls to open and become leaky.
Why are flowcharts useful for dichotomous keys?
They allow the researcher to visualize relationships between different bacteria.
Why are Koch's postulates important to microbiology?
They allowed us to identify the causative pathogens of many infectious diseases.
Which statement is true about standard precautions?
They apply to all healthcare providers working with all patients.
How are immune cells able to detect foreign pathogens?
They are able to detect structures on the surfaces of foreign cells that are not found in the host.
Which of the following is not a feature of eukaryotic flagella?
They are built from flagellin proteins.
All of the following describe 70S ribosomes except:
They are found in the cytoplasm of eukaryotes.
which of the following would be considered a FALSE statement about small noncoding RNAs?
They are found only in prokaryotic cells.
Which of the following is true about inorganic cofactors?
They are nonprotein agents.
What happens to the light rays when they hit the specimen?
They are reflected, refracted, or absorbed by the specimen.
What is a feature of the small fragments presented by MHC-I proteins?
They are small peptides, roughly 8-10 amino acids long.
Why are biochemical tests referred to as "fingerprint methods of bacterial species"?
They are used to identify bacterial species.
How are Cryptosporidium sporozoites able to evade the immune system?
They attach to host cells and build a protective membrane from modified host cell membrane materials.
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.
How do Shigella cells move between host cells?
They can polymerize actin molecules from the epithelial cells into tail-like structures that propel them from one cell to another.
How do superantigens enable pathogens to hide from the immune system if they actually stimulate the immune system?
They cause the immune system to produce an exaggerated response, distracting it from the actual pathogen.
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.
What is the hallmark of dichotomous keys?
They consist of a series of paired statements, in which only one statement of each pair applies to a given organism.
Which of the following statements describes eukaryotic cells?
They contain membrane-bound organelles such as a nucleus.
Of the following statements, which one is NOT related to transposable elements?
They create a stable, non-changing genome.
Which of the following statements about type III hypersensitivities is false?
They develop when IgD or IgE antibodies bind to insoluble targets.
Which of the following best describes the genomes of influenza, measles, Ebola, and rabies viruses?
They each have an RNA genome that is complementary to mRNA.
Why might broad spectrum antimicrobials be initially used when treating a patient?
They may initially be used to protect the patient since it can take several days to make a definitive bacterial identification.
How do phagocytes communicate to other cells what they have captured?
They present antigens from engulfed foreign cells.
How are viruses different from eukaryotic cells?
They require a host in order to reproduce.
How can surgeons help to limit nosocomial infections?
They should perform surgeries and invasive procedures only when absolutely necessary.
Choose the false statement about oncoviruses.
They stimulate cells to undergo apoptosis.
A virulence study was performed using Staphylococcus aureus in mice. It was determined that the LD50 for the S. aureus alpha-toxin was 0.045 µg/kg of body weight toxin (a relatively low LD50). In the same mouse population, the ID50 was determined to be 200,000 cells (a relatively high ID50). What do these results taken together mean?
This S. aureus strain is less infectious, but its alpha-toxin is highly-toxic.
How is this disease transmitted?
This disease is most commonly transmitted by unprotected sex.
Choose the true statement about pre-transcriptional regulation.
This form of regulation controls when and how often RNA is produced from a DNA template.
Which of the following lipids tends to be liquid at room temperature?
Unsaturated lipids
David had a lesion on his hand that was assessed by a nurse at his college's Student Health Services. The lack of bacterial growth on a nutrient agar plate indicated that the lesion was not caused by a bacterial infection. He was referred to an infectious disease specialist who ordered gram and acid-fast stains, and bacterial culturing on a blood agar plate of the lesion sample. The absence of bacteria observed by gram staining, and lack of bacterial growth the agar plate initially implied that bacteria were not present, but the detection of acid-fast organisms confirmed that the lesion was indeed cause by a bacterial infection. Why did the cultures at Student Health and at the Hospital not grow originally?
This organism is suited for growth at lower temperatures.
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
David had a lesion on his hand, so he went to his college's Student Health Services to have it assessed. After the nurse asked him background questions, she decided to swab the wound. Why did the healthcare provider swab the wound?
To get samples of any pathogens in the wound.
What is the role of epidemiology?
To learn how to treat and prevent various diseases
What is the function of the structural elements of a virus?
To package and protect the viral genome
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
What is the role of the ocular lens?
To recreate the image in the viewer's eye
What is the function of inflammation in response to a burn from a hot iron?
To repair the damaged tissue
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 of the following describes a case of food poisoning?
Toxins from Staphylococcus aureus, Bacillus cereus, and Clostridium perfringens are responsible.
________________ is caused by a Chlamydia species and is the leading cause of preventable microbial blindness.
Trachoma
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
Which of the following types of microscopy would be best to study how a novel virus interacts with its host cell?
Transmission electron microscopy
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
Which of the following microorganisms actually grows inside the macrophage?
Tuberculosis bacterium
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
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
Bacillus anthracis is a Gram-positive bacterial pathogen known to cause anthrax. B. anthracis secretes a three-protein toxin: protective antigen, lethal factor, and edema factor. Protective antigen binds the host cell surface at cell receptor TEM8. Following proteolytic cleavage, protective antigen forms a membrane channel that allows the passage of lethal factor and edema factor into the cytoplasm. Once inside, edema factor acts as an adenylate cyclase, while lethal factor acts as a zinc metalloprotease, both leading to reduced host cell signaling. Anthrax toxin is best described as a(n) ___________.
Type III exotoxin
Which of the following hypersensitivities are characterized by the slowest onset?
Type IV
Which of the following statements regarding type IV hypersensitivities is true?
Type IV hypersensitivities are delayed and typically manifest slowly over 12--72 hours after the stimulating antigen is encountered.
Why are type IV hypersensitivities called delayed hypersensitivity reactions?
Type IV reactions manifest slowly over 12-72 hours after the stimulating antigen is encountered.
What mRNA sequence is synthesized using the DNA template strand AATCCGAGGT?
UUAGGCUCCA
Which of the following is the primary distinguishing factor between uncomplicated and complicated urinary tract infections?
Uncomplicated urinary tract infections occur in otherwise healthy individuals with normal urinary tract structure, whereas complicated urinary tract infections usually occur in people with catheters, urinary tract malformations/obstructions, or immune-compromised people.
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?
Vancomycin
Which of the following antiviral drugs is mismatched with its mechanism of action?
Vapendavir: prevents rhinovirus attachment
Which of the following conditions in human is linked to bovine spongiform encephalopathy?
Variant Creutzfeldt-Jakob disease
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 methods uses samples from a liquid broth culture that are serially diluted and either spread on solid agar or poured into a petri plate with melted agar media to enumerate bacteria?
Viable plate count.
Which of the following is not used to classify and name viruses?
Virus size
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.
Which of the following is mismatched?
Viruses: Replication through mitosis.
Which of the following is mismatched?
Viruses: Usually viewed with light microscopy.
The first human virus was discovered in 1901. What scientist discovered the first human virus?
Walter Reed
Which statement is not true about viral warts?
Warts result from abnormal cell growth and so are highly likely to become cancerous.
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
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.
Your 30-year old patient presents to a Florida emergency room with fever, headache, flu-like symptoms, stiff neck, disorientation, and convulsions. You notice that there are several insect bites on her arm, which she tells you are mosquito bites from a camping trip two days ago. Based on the patient's case history and disease presentation, which of the following pathogens did your patient most likely contract?
West Nile virus
What features of West Nile virus make it an emerging disease of special concern?
West Nile virus is an arthropod-borne virus transmitted by mosquitoes. West Nile virus has a high mortality rate in immunosuppressed humans and infects many species of birds in southern Europe, the Mediterranean basin, and North America. West Nile virus is maintained in nature through biological transmission between susceptible hosts by blood-feeding arthropods
Which of the following best describes why West Nile Virus is considered to be an emerging infectious disease?
West Nile virus outbreaks have increased in number and affected areas since 1937.
Which of the following best describes a prophage?
When a phage genome is integrated into the host cell's chromosome
How is translation terminated?
When a protein called a release factor enters and binds to the A site
When would endotoxins be released from a bacterial cell?
When the cell dies
When could hemolytic disease of the newborn occur?
When the father is Rh+ and the mother is Rh-
Which of the following skin infections is caused by a protozoan?
Which of the following skin infections is caused by a protozoan?
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
While working at a clinic in Angola, you attend to a patient who presents with jaundice, high fever, and severe headache. Upon close inspection, several mosquito bites are observed on the patient's arms and legs. Which of the following is the most likely cause of the patient's symptoms?
Yellow fever
Is it possible for Rudy's warts to spread to other areas of his body?
Yes. Papillomaviruses are spread by direct contact.
Is Grandfather Davis contagious?
Yes. The twins would probably develop chicken pox 2 weeks after their visit with Grandfather Davis
What observations could you make in the case of a positive catalase test?
You may see bubbles develop upon adding hydrogen peroxide to the sample.
Which of the following types of transport would only be found in living cells?
active transport
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.
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.
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.
Which of the following scenarios is an example of a primary immunodeficiency?
Your patient is born with agammaglobulinemia, a genetic condition that leads to decreased antibody production
Which of the following would be observed as a result of vulvovaginal candidiasis?
a "cottage cheese" discharge
Pelvic inflammatory disease is characterized by all the following except
a clear set of signs and symptoms that make diagnosis straightforward.
The chromatin is
a collection of DNA and protein.
Autoimmune disorders are diagnosed using
a collection of tests and careful assessment of signs and symptoms.
Hyphae are
a collection of tubular structures that result from fungal growth.
Secondary immunodeficiences are commonly caused by __________.
a decline in immune system rigor
In streptococcal toxic shock syndrome, pathology results from toxins in the bloodstream which may cause both a red skin rash, as well as
a decrease in blood pressure leading to organ failure.
A major factor in the re-emergence of vaccine-preventable diseases in the early 21st century has been
a flawed research study incorrectly linking vaccination to autism was published in the late 1990s.
The cytoplasmic membrane could best be described as _________.
a highly selective, permeable barrier
An antibiotic is
a naturally occurring compound that kills microbes or inhibits their growth.
A DNA vaccine involves placing genes into a 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
Lysogenic viral DNA which has integrated into the host genome is referred to as
a prophage
Which of the following is considered a pre-transcriptional regulation and NOT a post-transcriptional regulation?
a repressed operon
In an inducible operon, what protein is used to turn off transcription by binding to the operator sequence?
a repressor protein
A transposon that relies on an RNA intermediate is called __________.
a retrotransposon
Anatomical factors that cause women to be at higher risk of urinary tract infections than men include
a shorter urethra positioned closer to the anus in women.
The primary immune response involves
a slow rise in the concentration of antibodies, followed by a gradual decline.
What is the intermediate product formed by pyruvic acid during alcoholic fermentation?
acetaldehyde
Which molecule is the product of the intermediate step which is a direct input into the Krebs cycle?
acetyl CoA
Organisms that are found growing in sulfur hot springs and volcanic vents are __________.
acidophiles
If a superbug is resistant to an antibiotic due to horizontal gene transfer, the microbe is said to have
acquired resistance.
Antibodies do all the following except
activate killing by T cytotoxic cells.
A variety of bacteria normally inhabits the vagina. How could a practitioner differentiate between these normally present bacteria and Candida albicans just by looking at a wet mount sample under the microscope without differential staining procedures?
all of the statements are correct
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 phagocytosis
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
Which protozoan disease would be responsible for the symptoms seen in this patient?
amebiasis
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 ______.
aminoglycosides
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
The infectious agent that causes tuberculosis is
an acid-fast bacterium of the genus Mycobacterium.
An essential amino acid is __________.
an amino acid the cell cannot make and must obtain from the environment
An anion is formed when
an atom gains one or more negatively-charged electrons.
Congenital toxoplasmosis can cause all of the following except
anemia
Nematodes, tapeworms, and flukes are members of the kingdom _________.
animalia
An anamnestic response is
another name for secondary response.
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
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
A substance that may trigger an immune response, if presented in the right context is termed a(n)
antigen
Which of the following is not required for T cell activation?
antigen
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 masking
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?
antigenetic shift
Yearly vaccinations for influenza are necessary due to __________.
antigenic drift
Pandemic outbreaks of influenza are the result of __________.
antigenic shift
Along with intravenous rehydration, many of the medication groups listed below may be used for secondary infections. But which group must be used if the infection is to be controlled?
antiprotozoan medications
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
Properties that contribute to virulence
are determined by both the microbe and the host, and may evolve over time.
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.
Cutaneous mycoses usually
are superficial infections on the skin, hair, or nails.
Live attenuated vaccines
are the closest to the actual infectious agent encountered in nature and stimulate potent immune responses to multiple antigens on the pathogen.
Biochemical tests _________________.
are the main methods used to identify unknown bacteria
T-independent antigens
are usually polysaccharides and able to bind multiple B cell receptors on a given B cell.
Which of the following would be an example of a chemical mutagen?
arsenic
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
In which stage does formation of mature viruses occur?
assembly
The normal function of the PrP protein in mammals is believed to be:
assisting in normal synaptic development and function.
Which stage of animal virus replication may be blocked by a drug that binds with the viral spike?
attachment
What type of vaccine would be used to vaccinate the twins?
attenuated virus vaccine
Which of the following methods uses steam-heat and pressure to effectively sterilize microbiological media and equipment?
autoclaving
A combination of _________ and _________ must be used to eliminate prions from surgical devices.
autoclaving; chemical treatment
___________ are transplants from self, like a self-skin graft from one part of the body to another location.
autografts
A child with no known congenital problems is diagnosed with inflammation of the heart valves. The medical history of the child is unremarkable except for a sore throat and fever six weeks prior, which the parents attributed to a common cold. The heart valve inflammation is most likely due to
autoimmune complications of Streptococcus pyogenes
Quorum sensing allows bacteria within communities to communicate with chemical messages, which may help regulate gene expression. The chemical messages are called __________.
autoinducers
What does the "A" in S.M.A.R.T. stand for?
avoid distractors
Which of the following drugs are not matched correctly with their mode of action?
azoles: inhibits ribosome function by entering ribosome as a tRNA, covalently binding to mRNA, and forcing the destruction of the complex
Which organism(s) ferment(s) lactose?
b and c
Which domain of the A-B toxin binds to cell surface receptors on the host cell?
b domain
Using the more complex key on the previous slide, which organism would be described by the following characteristics: •Gram positive bacilli •Spore-former positive •Mannitol positive •Voges-Proskauer positive
bacillus subtilis
What type of microbe causes lymphogranuloma venereum?
bacteria
Which of the following is an endogenous source of infection?
bacteria from the skin entering a surgical incision
Which of the following is an example of a biofilm?
bacteria growing in plaque
The image shows the results of a type of structural staining method called a negative stain that uses the dye, crystal violet. What are the purple colored structures depicted by the arrows?
bacterial cells
Staphylococcus aureus is streaked on MSA and allowed to grow overnight at 37ºC. What results would you expect to observe on MSA?
bacterial growth with yellow colored media
Which granulocyte contains granules packed with histamine, that stain dark purple?
basophils
Prokaryotes reproduce via _________.
binary fission
Which of the following is not a mechanism for horizontal gene transfer?
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
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.
The host DNA is usually degraded during which stage?
biosynthesis
The next day Richard examines the EMB plate filters. The results are as follows: The EMB agar average two blue colonies / plate.
black: fecal colony red: nonfecal colony
Which of the following is not one of the four cardinal signs of inflammation?
bleeding
How can a chikungunya infection be differentiated from a dengue infection?
blood tests that identify viral antigens, viral RNA, or patient antibodies to the virus
In order to kill the fungus in a patient's body without causing unnecessary damage to his cells, a drug must be used that targets a structure common to fungi but not found in human cells. Which of the following would make an ideal drug target in this case?
cell wall
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
A Case of Genital Sores A 20-year-old sexually active college student reports to his campus clinic complaining of genital sores. The ulcers are soft, painful, and pus-filled. Upon questioning, the student reveals his current girlfriend is an Asian exchange student. The campus lab initially has difficulty identifying the causative agent, but finally is able to isolate a Gram-negative coccobacillus on What disease has this patient contracted?
chancroids
Sophisticated proteins require __________ to help with folding into the final protein structure.
chaperones
Medically important microbes are metabolically classified as __________.
chemoorganoheterotrophs
Organisms that breakdown chemical compounds for energy are called _________.
chemotrophs
In __________ viral infections, there is a continuous release of virions over time and a slow progression of disease.
chronic
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
Autoimmune disorders are
chronic conditions that develop from the immune system attacking healthy self-tissues that should normally be left alone.
Which of the following prion diseases is found in deer and elk?
chronic wasting disease
Which of the following suggests mitochondria evolved from prokaryotic ancestors?
circular DNA
What do chronic hepatitis infections result in?
cirrhosis, liver failure, or hepatocellular carcinoma
Which topical medication would likely be recommended for use in this case?
clotrimazole cream
What is the indicated structure on this pictured microscope?
coarse focus (inner part of knob)
You receive results back from the lab that your patient is infected with Vibrio cholera. This organism is a _________-shaped organism.
comma
Although four of the following options describe both rotavirus and norovirus, which one specifically describes norovirus?
common in long-term care facilities
If a cell is to be transformed in a lab, the cell must be __________ to uptake the available genetic information.
competent
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 and 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
What is the indicated structure on this pictured microscope?
condenser
Which of the following can cause primary immunodeficiencies?
congenital immunodeficiency
Which of the following type of fungal spores arise from mitosis and do not result in genetic variation?
conidiospores
The exchange of genetic information by use of a pilus and cell-to-cell interaction is called __________.
conjugation
The common infection known as "pink eye" is an infection of the
conjunctiva.
During optimum conditions, E. coli will replicate every 20 minutes. Because the genes required for replication are needed as part of a routine function, these genes are considered __________.
constitutive genes
When aerosols containing pathogens spread disease from a distance of less than one meter, it is considered
contact transmission
How can this disease best be categorized?
contagious and chronic
The most common cause of atypical pneumonia, Mycoplasma pneumoniae, has all the following characteristics except
contains more genes than most other bacteria.
The genetic code
contains sense codons and nonsense codons.
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
Of the following intermediates in glycolysis, which is used to generate the glycerol molecules in lipids?
dihydroxyacetone phosphate (DHAP)
Which of the following is not a sign of sepsis?
dilated pupils
The development of a pseudomembrane on the tonsils and throat is characteristic of
diphtheria
Substrate-level phosphorylation can be defined as __________.
direct transfer of a phosphate group enzymatically from one substrate to an ADP molecule
_________ reduces the number of microbes on a given non-living surface of a sample.
disinfection
All of the following are anti-influenza drugs except ____________.
docosanol
What is the definition of a true pathogen?
does not require a weakened host to cause disease
What is the order of the taxonomic hierarchy from least specific to most specific?
domain, order, class, kingdom, phylum, species, family, genus
Under ideal conditions, E. coli's generation time is 20 minutes. This means that if conditions are ideal, the number of E. coli cells in a given population will _________ in 20 minutes
double
Which of the following properties of RNA is false?
double-stranded
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
Heating an inoculating loop in a Bunsen burner until it glows red to sterilize it is an example of __________.
dry heating
Which nucleic acid is part of the varicella-zoster virion?
dsDNA
Which of the following is not directly involved in protein synthesis?
dsRNA
Which of the following would not be important when evaluating measures of association?
duration of the disease
Which factors may result in a normal microbiota species causing disease?
dysbiosis due to antibiotic therapy or invasion of other tissues by the microbiota species
What happens if lymph is not collected?
edema
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 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
A urine dipstick test can diagnose urinary tract infections by indicating
elevated levels of leukocyte esterase.
What is it called when there is only inflammation of the brain?
encephalitis
The common cold is a(n) _________ disease.
endemic
David had a painful lesion on his hand and went to his college's Student Health Services to have it assessed. After the initial test results were negative for the presence of bacteria, he was referred to an infectious disease specialist to determine the cause of his lesion. The doctor wanted to test David's lesion for Bacillus anthracis. If this organism is grown in stressful conditions, what differential stain would most add to the presumptive diagnosis of cutaneous anthrax?
endospore stain
The image shows the results of a structural staining method that uses malachite green as the primary stain and safranin as the counterstain. What is the name of the staining method?
endospore stain
All of the following are examples of inclusion bodies in prokaryotic cells except __________.
endospores
The image shows the results of a structural staining method that uses malachite green as the primary stain and safranin as the counterstain. What are the green colored structures depicted by the arrows?
endospores
The viral __________ is often comprised of the host cell membrane.
envelope
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
Which granulocyte when stained exhibits red-orange granules, is moderately phagocytic, and attacks allergens and parasites?
eosinophils
The parts of an antigen that B and T cells recognize and mount an immune response against are called _________.
epitopes
Based on the observations given, what is the probable diagnosis made by the health care provider?
erysipelas
What is one of the virulence factors associated with the causative agent for this infection?
erythrogenic toxin
What would be the best treatment options?
erythromycin
If there is not enough time between determination of an STD in the pregnant mother and time of delivery, after birth the doctor may choose to prophylactically treat the infant for infections. What would the treatment be?
erythromycin cream initially placed in the newborn's eyes
In DNA replication, protein factors are more heavily required for replication in __________.
eukaryotic cells
The process of removing incorrect nucleotides and replacing them with correct ones is referred to as __________.
excision repair
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
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
Which of the following events might trigger induction of a temperate bacteriophage?
exposure to UV light
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
You inoculate a semisolid thioglycolate medium with a pure culture of Staphylococcus aureus. You incubate the sample under optimal growth conditions (37°C). Following incubation, you observe heavy growth at the top of the tube and moderate growth near the middle and bottom portions of the tube. Based on this observation, Staphylococcus aureus would be best classified as a(n)?
facultative anaerobe
Organisms that can survive in both aerobic and anaerobic environments are known as __________.
facultative anaerobes
Although Staphylococcus aureus can grow at 7% NaCl, it grows best at NaCl levels less than 1%. This organism is a __________.
facultative halophile
A disinfectant cannot be used to achieve sterility; instead, this type of germicide is only used to achieve disinfection.
false
Next, Richard observes the HE plate. The results are as follows: Only a few yellow/orange colored colonies are observed The HE results indicate the presences of Salmonella
false
When taking a blood sample, a disinfectant is used to remove microbes from a patient's skin prior to drawing blood.
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
Of the following, which pathway is not part of cellular respiration?
fermentation
Which of the following is not a cardinal sign of inflammation?
fever
Which of the following would be the first sign of an infection that resulted in the release of endotoxin?
fever
Chlamydia and gonorrhea often present a similar clinical picture except that
few strains of chlamydia are antibiotic-resistant while gonorrhea shows extensive antibiotic resistance.
A distinctive red rash on the cheeks with an otherwise mild illness is most likely
fifth disease.
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.
Large volumes of liquids or air can be sterilized using __________.
filtration
Short, bristle-like structures that extrude from the surface of a prokaryotic cell are called
fimbriae
Which picture shows an icosahedral enveloped virus with spikes?
first one, shape with circle and spikes
Kupffer cells are examples of ________ that reside in the _________.
fixed macrophages; liver
A man presents to the physician's office complaining of irritation in the genital area. Examination reveals a bright red rash with raised pustules with clear fluid. Upon questioning, the man reports he has recently been sexually active. What is the most likely diagnosis based upon the appearance of the genital lesions?
genital herpes caused by HSV-2
The genetic makeup of an organism is its __________.
genotype
Which of the following can be a primary energy source of a bacterial cell?
glucose
Which of the following molecules is broken down in cellular respiration, providing fuel for the cell?
glucose
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
Which of the following statements about glycolysis is true?
glycolysis is also called the Embden-Meyerhof pathway.
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
Which of the following is part of the endomembrane system?
golgi apparatus
What disease does this patient have? What is the common name for this disease?
gonorrhea; "the clap"
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
Organisms that thrive in high salt conditions are known as __________.
halophiles
A 21-year-old male is admitted to the hospital in severe respiratory distress. Despite care, he died of rapid pulmonary edema within 12 hours of admission. Family members report that he had recently started work at a nearby state park. He was on a detail to clean out and renovate a group of rodent-infested rental cabins. Based on the information, what is the likely diagnosis?
hanta pulmonary syndrome
Characteristics of the human papilloma virus include all except
have a high mutation rate, meaning vaccine development is challenging.
Carriers of the sickle-cell gene
have a survival advantage in areas where malaria is common.
Which is not a specific cause of reactivation of HSV-1?
having a cold or fever
Which of the following is not needed to carry out excision repair in Escherichia coli?
helicase
Onchocerciasis, or river blindness, is caused by a ________ and is spread via ________.
helminth; blackflies
Which of the following pathogen agents is multicellular?
helminths
Which two hepatitis viruses primarily use the fecal-oral route for infection?
hepatitis A and hepatitis E
The immediate result of electron movement through the electron transport chain is the pumping of protons across the bacterial cell membrane, creating a _____ outside the cell than inside the cell.
higher concentration of protons
Cytopathic effects induced by a virus include __________.
hijacking cellular machinery and disrupting normal host cell function
Which of the following acts as a proinflammatory factor?
histamine
The Ames test is used to identify if a chemical will result in mutations. This test uses the microorganism S. typhimurium and the amino acid __________.
histidine
Bacteria used to make yogurt produce lactic acid only as a byproduct of fermentation. These organisms are said to use _________.
homolactic fermentation
The process of transferring of genetic information between cells in the same generation is referred to as __________.
horizontal gene transfer
Which factor may influence the specific types of microbes found on the skin?
hormones, moisture levels, and soap and cosmetics usage
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
Which virulence factor of Group A streptococci (GAS) is responsible for the rapid spread of tissue death in necrotizing fasciitis?
hyaluronidase and streptokinase
The partial positive charge on the hydrogen end of a water molecule forms a __________ bond with the partial negative charge on the oxygen end of an adjacent water molecule.
hydrogen
Which of the following would be the weakest bond?
hydrogen bond
A chemical reaction that breaks down complex molecules using water is a(n) __________ reaction.
hydrolysis
You are working with a substance that readily dissolves in water. It is said to be _______.
hydrophilic
Who is primarily at risk for a candidiasis infection?
immunocompromised individuals who have underlying conditions such as cancer, diabetes mellitus, AIDS, or who are taking medication that suppresses the immune system
A patient with a newly transplanted organ is likely prescribed __________ in order to limit the risk of transplant rejection.
immunosuppressants
Several forms of keratitis are linked to
improper handling of contact lenses.
Lophotrichous flagella are found:
in a cluster at one end pole of the cell.
Adhesins
include molecules that bind to host factors such as fibronectin, sialic acid, and heparin / heparin sulfate.
Distinct collections of substances inside prokaryotic cells are known as _________.
inclusion bodies
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.
Which factor is not a reason Propionibacterium acnes (P. acnes) is often associated with acne?
increased oxygen levels in clogged pores favoring bacterial growth
Which of the following is not a factor in increased incidence of fungal infections?
increasing antibiotic resistance
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
Which of the following would be considered a fomite?
infected toy
In order to successfully and safely deliver a gene to a human cell, a virus vector must be
infectious but not pathogenic.
1) In the complement pathway, C3a and C5a are both involved with ______________. ]
inflammation and enhancement of phagocytosis
In the United States, most common exposure to Clostridium botulinum and its toxins occurs through __________.
ingestion of the spores or toxins in improperly canned foods
How did this couple become infected with C. jejuni?
ingestion of undercooked poultry
Transmission of the causative bacterial agent is via this route.
inhalation of respiratory droplets
Patients who suspect exposure to rabies are
injected with both antirabies antibodies and the inactivated vaccine.
Which portion of the mitochondria is folded to create a large surface area?
inner membrane
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
Where do Salmonella pathogens grow and replicate in the infected host?
inside phagocytes
An effective treatment for hepatitis B and hepatitis C is __________.
interferon-alfa
_________ play a role in hematopoiesis.
interleukins
What would be the best course of action to treat someone who has been exposed to Clostridium boltulinum toxin or has had a Botox injection that is spreading?
intravenous immunoglobulins
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
In eukaryotic mRNA, there are sequences of mRNA that do NOT encode for specific amino acids and do NOT contribute to the protein. These sequences are called __________.
introns
Chloride (Cl-) is most likely to form a(n) _________ bond with _________.
ionic; Na+
Antigen processing and presentation
is a way for a cell to give information about its activities.
In a 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.
Characteristics of Treponema pallidum, the bacterium which causes syphilis, include all except
not treatable with any of type antibiotic.
The most common drugs that block replication are ________.
nuceloside analogs
Where is the chromosomal DNA found in prokaryotic cells?
nucleoid
Prokaryotic cells house a single circular chromosome in their __________.
nucleoid region
The DNA of a prokaryotic cell is found within the ___________.
nucleoid region
Prokaryotic DNA is found in the __________ region and eukaryotic DNA is located in the ___________.
nucleoid, nucleus
Where is the genetic information of the cell stored?
nucleus
Which of the following cell structures are only found in eukaryotic cells?
nucleus
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 _________.
nystatin
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-
What is the indicated structure on this pictured microscope?
objective lens
Organisms that have an absolute dependence on abundant oxygen for cellular processes are __________.
obligate aerobes
Organisms that die in the presence of oxygen because they cannot eliminate reactive oxygen species are known as __________.
obligate anaerobes
Of the following, which would be considered a biochemical test?
observing a change in pH after the breakdown of a substrate
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.
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
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 is an outcome of complement activation?
opsonization, cytolysis, and inflammation
Which term represents the temperature that bacteria grow the fastest at?
optimal
What should the course of treatments for this infection entail?
oral antibiotics
What is the recommended course of therapy?
oral fluids
Halophiles are able to tolerate osmotic stress by concentrating __________ in the cytoplasm.
organic materials
This image shows the results of three different bacterial species grown on EMB. All three organisms have grown on the media. What does the appearance of the growth of organism "C" indicate?
organims "C" exhibited an abundance of lactose fermentation resulting in a metallic sheen
At what site on the chromosome does DNA replication begin?
origin of replication
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.
outer membrane; negative
If some students wanted to determine if an organism used cytochrome c in cellular respiration, which test would they perform?
oxidase
Which route of entry occurs when microbes enter the body through bites, cuts, injections, or surgical incision?
parental
Which portal of entry is mismatched to its description?
parenteral: pathogen is passed from mother to child through the placenta
Which of the following does the mumps virus infect?
parotid glands
Riboswitches are best defined as __________.
parts of mRNA that are not translated and act as post-transcription regulators
__________ uses moderate heat to reduce levels of pathogens in liquids.
pasteurization
In which stage is the viral DNA introduced into the cell?
penetration
What kind of bond is formed when two amino acids join together?
peptide bond
Which of the following molecules is not found in the plasma membrane?
peptidoglycan
What cells or tissues will harbor the bacteria in a patient with Hansen disease?
peripheral nerve endings, mucous membranes, and skin cells in the fingers, toes, lips, and earlobes
Bacteria with flagella distributed all over the cell surface are described as having:
peritrichous flagella
Infectious mononucleosis is spread through kissing or other close contact between the host and a healthy individual. This is considered _________.
person-to-person transmission
These two secondary lesions arise when bleeding or burst capillaries occur in the skin.
petechiae and purpura
Botulinum toxin causes all of the following except
petechial rash.
Prophages sometimes provide bacteria with genes that encode pathogenicity factors through a process called _________.
phage conversion
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
Which functional group is found at the 5' end of DNA?
phosphate group
The prokaryotic plasma membrane is primarily made of____________.
phospholipids.
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
UV radiation can result in DNA mutations called thymine dimers. Which of the follow DNA light-repair enzymes remediate thymine dimers?
photolyase
Which subcategory of first-line defenses does skin belong to?
physical
Which of the following structures allow bacteria to transfer genetic information through conjugation?
pili
Phytosterols are characteristic of the plasma membrane of __________ cells.
plant
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
Growth of bacteriophages on a lawn of bacteria is indicated by the presence of __________.
plaques
When mixed with their host bacterium and plated on solid agar, lytic phage will form clear areas in the bacterial growth. What are these clear areas called?
plaques
What structure acts as a selective barrier, regulating the traffic of materials into and out of the cell?
plasma membrane
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
Prokaryotic and eukaryotic extrachromosomal DNA is called ______ DNA.
plasmid
Prokaryotic and eukaryotic extrachromosomal DNA is called ______.
plasmid
Which type of genetic material may be found in both prokaryotic and eukaryotic cells and may contain genes conferring antibiotic resistance?
plasmids
All the following apply to B cells except
play a critical role in both the cellular and humoral responses.
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
One major difference between prokaryotic and eukaryotic translation is __________.
prokaryotic translation is polycistronic, and eukaryotic translation is almost always monocistronic.
What is the initial target of RNA polymerase?
promoter
An antiretroviral regimen usually consists of two reverse transcriptase inhibitors and a(n)
protease inhibitor, integrase inhibitor, or reverse transcriptase inhibitor.
What role do capsules and protein A play as virulence factors of Staphylococcus aureus?
protect the bacterium from phagocytosis
Deamination is important in __________.
protein catabolism
Each element is identified by their atomic number, or number of _________.
protons
__________ is not an official taxonomic rank, rather it is a convenient term for describing animal-like protists that are unicellular, lack a cell wall, exhibit asexual and sexual reproduction, and live by heterotrophic means.
protozoan
Organisms that prefer to grow at temperatures between -20°C and 10°C are called_________.
psychrophiles
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
Listeria monocytogenes grows best at refrigerator temperatures and is therefore considered 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 particle and are then mixed with GEM particles, an adjuvant. This type of vaccine is known as a(n):
purified, subunit vaccine.
Which of the following primary skin lesions is a raised lesion that contains pus and is found below the skin surface?
pustules
Of the following, which is the most serious condition?
pyelonephritis
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 is NOT an end product of fermentation?
pyruvic acid
Which of the following are contributors to viral genome evolution?
quick replication time and the large number of virions released within a host
Ribosomes contain which of the following?
rRNA
What disease is transmitted from bats to humans and produces the signs/symptoms displayed by this patient?
rabies
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 presence of specific ___________ on viruses determine whether it can infect a particular cell or not.
receptors
The 2014 outbreak of Ebola spurred the development of a new vaccine for this disease. The newly designed vaccines were ________.
recombinant vector vaccines
Compared to complicated urinary tract infections (UTIs), uncomplicated UTIs are less likely to
recur after initial treatment.
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
Which stage of viral replication is shown?
release by budding
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.
the golgi apparatus:
resembles a series of disc-like, flattened sacs called cisternae that stack upon one another.
_________ is the ability to distinguish two distinct points as separate.
resolution
Endemic mycoses are
restricted to a specific geographic location.
Which enzyme is used to generate compatible sticky ends in order to join a desired gene to a plasmid vector in recombinant DNA techniques?
restriction enzymes
Latent tuberculosis
results when M. tuberculosis bacteria are phagocytized and effectively walled off within granulomas in the lungs.
cDNA is a product of the action of __________.
reverse transcriptase
The CRISPR-Cas9 system uses all except which of the following?
reverse transcriptase enzyme
RNA nucleotides are made of a sugar, a phosphate, and a nitrogen base. Which sugar is unique to RNA nucleotides and NOT found in DNA nucleotides?
ribose
One of the ways smooth endoplasmic reticulum (ER) differs from rough endoplasmic reticulum is that rough ER is covered by
ribosomes
Which of the following is not needed during transcription?
ribosomes
Which of the following describes how blood travels through the heart?
right atrium, right ventricle, lungs, left atrium, left ventricle, rest of the body
Which structure pictured is the site of synthesis of proteins destined for secretion?
rough endoplasmic reticulum
Which grouping of parasitic helminths includes hookworms?
roundworms
Which factor, beginning in 1995, is responsible for the decline in chicken pox from a routine childhood disease to a rare infection?
routine vaccination
Pregnancy tests are examples of _________.
sandwich ELISAs
Which biological molecule is shown in the picture?
saturated fatty acid
Which of the following diseases makes antibodies against centromeres and topoisomerases?
scleroderma
Which disease did Stanley Prusiner first identify as being caused by prions?
scrapie
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
Which type of media has ingredients that foster the growth of certain bacteria while suppressing the growth of others?
selective
EMB media is a selective and differential diagnostic media. What does EMB select for? What does it differentiate?
selects for gram-negative organisms and differentiates between organisms that can or cannot ferment lactose
MacConkey media is a selective and differntial diagnostic media. What does MacConkey select for? What does it differentiate?
selects for gram-negative organisms and differentiates between organisms that can or cannot ferment lactose
There are two nonstandard encoding amino acids: __________.
selenocysteine and pyrrolysine
Which form of a Yersinia pestis infection can result in acral gangrene caused by intravascular coagulation?
septicemic plague
Pertussis is characterized by
severe coughing attacks where the patient struggles to catch their breath.
The role of healthcare workers in the management of disease outbreaks
should be addressed through periodic training and re-training.
The health of the patient
should be the primary concern of the healthcare worker.
Which of the following is an organic molecule made by bacteria that sequesters iron from host iron-binding proteins?
siderophore
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.
Saturated lipids have ______ bonds in their fatty acid chains.
single
Which of the following can be determined using simple stains?
size, shape and cellular arrangement
Which of the following is the most important physical barrier of the first line of defense?
skin
Athlete's foot is caused by a variety of different fungal infections. The presentation of a severe case would look much like the photograph here. The interdigital spaces and any moist areas of the foot are likely to be affected first. As the disease progresses, the nail and nail bed become affected. Once the nails are infected, the course of treatment must involve three different areas. First, the feet must be kept clean and dry. This includes allowing shoes to air dry for 24 hours between wearings, wearing shoes made of leather or other "breathable" materials, using antifungal powders inside the shoes, changing socks at least twice daily, wearing sandals whenever practical, washing the feet with soap twice daily, and applying an astringent. Additional precautions include always wearing shower shoes in public showers/locker rooms and not sharing towels or wearing another person's shoes to prevent contact with the fungus and reinfection. Second, an appropriate antifungal cream, such as clotrimazole, should be applied to clean, dry feet daily. This helps to kill the infection from the outside toward the inside of the body. Third, in advanced cases that involve the nail bed, oral medications are necessary for at least 12 weeks and often up to 6 months (until the new nail is visible and free of fungal discoloration and texture). This kills the fungus from the inside of the skin toward the surface. What would be the most effective oral agent to use for treating the condition depicted in this case?
terbinafine tablets
What part of the nervous system is most affected by fatal familial insomnia?
thalamus
One of the most commonly used viral cell cultures is __________.
the HeLa cell line
Histoplasmosis should be suspected in cases of fungal respiratory infections found in
the Mississippi and Ohio River valley regions.
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.
Guanosine triphosphate (GTP) and uridine triphosphate (UTP) can be used to provide energy during some cellular reactions; however, the cell prefers energy in the form of ATP. This preference is due to __________.
the ability of most enzymes to use ATP to catalyze reactions
TORCH pathogens are all characterized by
the ability to cross the placenta to infect a developing fetus.
The unique chemical and physical properties of an enzyme's active site allow for __________.
the active site to be specific for one substrate
Phosphorylation is __________.
the addition of a phosphate onto an ADP molecule through catabolic reactions
This image shows the results of different bacteria inoculated onto an EMB plate. What does the metallic green-colored growth indicate?
the bacteria are gram-negative lactose fermentors
An organism is inoculated on an MSA plate. After incubating the plate to allow for bacterial growth, no growth is observed. Why didn't the bacteria grow on MSA?
the bacteria couldn't grow in the presence of high salt concentrations
A chief concern of the health care provider with an infection such as this one would be which of the following?
the bacteria spreading to the blood (bacteremia) and damaging the heart or the kidneys
Where are the complement proteins found in the body?
the blood serum
Which of the following is not a virulence factor of Shigella species?
the capability to cause stomach ulcers
Which of the following would be the most complete definition of metabolism?
the cell's ability to break down carbon substances, releasing energy to create new compounds for cellular needs
The branches of adaptive immunity are
the cellular response and the humoral response.
The term used by molecular biologists to describe the flow of genetic information from DNA, to RNA, to protein is __________.
the central dogma of biology
Antibodies from cellular immune responses are used in
the classical pathway.
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.
All of the following can make interpreting the Gram stain difficult except
the culture is between 24 and 48 hours old.
Why are RNA viruses that use RNA-dependent RNA polymerase for transcription more likely to have genome mutations?
the enzyme doesn't have proofreading capabilities
Describe the function of the indicator, neutral red, when the bacteria growing on MacConkey media ferment lactose.
the indicator will change from colorless to pinkish
In DNA replication, Okazaki fragments are required in synthesizing __________.
the lagging strand, because the DNA polymerase can move only in the 5' to 3' direction
Emigration is
the migration of phagocytes through blood vessels to the site of tissue damage.
What is the major challenge with developing new synthetic antimicrobials?
the need to screen thousands of potential candidates
ID50 describes
the number of cells or virions needed to establish an infection in 50 percent of exposed hosts.
The plaque assay allows researchers to determine __________.
the number of lytic bacteriophages in a sample
Isotopes are atoms of the same element that differ in
the number of neutrons found in the nucleus.
An organism is streaked onto MSA and allowed to grow overnight at 37º C. The plate has bacterial growth, but the media remained a pinkish color. What do the results indicate about the organism?
the organism can grow in high salt conditions, but cannot ferment mannitol
A key factor in the high prevalence of otitis media in children is
the orientation of the eustachian tube in children prevents efficient fluid drainage.
What redox reactions provide energy for the electron transport chain?
the oxidation of the carbon molecules and the reduction of the electron carrier coenzymes
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.
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.
Evidence in support of the endosymbiotic theory includes
the presence of 70S ribosomes in mitochondria and chloroplasts.
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
What determines which form of Hansen disease a person will develop after infection with the causative bacterium?
the state of a person's immune response during early development of the disease
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
While there are many similarities between aerobic and anaerobic cellular respiration, the major difference occurs in __________.
the terminal electron acceptor
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
Viral tropism describes __________.
the tissues or cells a virus can infect
Influenza A strains are characterized by
the type of HA and NA spikes found on the viral surface.
Viruses are considered to be non-living pathogens for which reason?
their lack of metabolic processes
Vaccine prevention of acute respiratory infections (the common cold) is unlikely because
there are many distinct virus strains and serovars that cause the common cold.
The __________ is the minimum temperature needed to kill all microbes in a sample within ten minutes.
thermal death point
The minimum temperature needed to kill all microbes in a sample within ten minutes is called the
thermal death point
The __________ is the shortest period of time that a given temperature must be held to kill all microbes in a sample.
thermal death time
__________ are organisms that dwell in compost piles and hot springs.
thermophiles
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.
Urinary catheters pose risks of causing urinary tract infections because
they provide a surface for bacterial biofilms to establish and they can introduce bacteria from the skin, anal, or external genital areas into the bladder.
If a patient notices a healthcare worker not following suggested precautions,
they should immediately bring it to the attention of the healthcare worker.
Which of the following key chemical mediators in inflammation is not matched to its function?
thromboxanes: reduce pain receptor stimulation and reduces fever
Lyme disease is spread _________.
through biological vectors
Griffith's experiment proved that bacteria can take up naked DNA from the environment and use it as part of their genome. This process, which can occur in a laboratory or in a natural setting, is called __________.
transformation
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
Which of the following amino acids is coded by only one codon?
trp
The EMB results seen above would accurately be reported as two fecal coliforms / 100 ml water sample.
true
The symptoms point toward a form of Hansen disease. Which form of the disease best fits the symptoms that are being seen by the nurse?
tuberculoid leprosy
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
Lupus is a ________ hypersensitivity characterized by ______.
type III; a rash across cheeks and nose, fatigue, and joint pain
Which of the following hypersensitivities are T cell-mediated responses against self-antigens or otherwise harmless antigens?
type IV hypersensitivities
Allergies are classified as:
type i hypersensitivities
RNA is distinguished from DNA because only RNA:
typically exists as a single-stranded molecule.
A fungal species which can grow in varied climates and under diverse conditions is termed
ubiquitous
Artemisinin-based combination therapies are used to treat
uncomplicated and severe cases of malaria.
A major difference between protozoans and helminths is that protozoans are
unicellular
helicase
unwinds the DNA
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 nucleotides is found only in RNA and not in DNA?
uracil
Areas with a high population and low vaccination rates are susceptible to which type of transmission for yellow fever?
urban
What is the best way to protect the population against Haemophilus influenza type b infections?
use of the Hib vaccine in young children
Retroviruses produce mRNA by:
using reverse transcriptase to convert single- stranded RNA (ssRNA) to double-stranded DNA (dsDNA) and then using the dsDNA for transcription.
A parent calls the pediatrician's office about uncomfortable sores on the inside of her child's mouth. You suspect hand, foot, and mouth disease (HFMD), but need to rule out measles. Which information could help you to rule out measles?
vaccination history
To reduce the chances of bacterial meningitis, the CDC recommends what actions be taken for military recruits and college freshman?
vaccinations for meningococcus
Which of the following prion diseases may be acquired by eating beef contaminated with a cattle prion?
variant CJD
There are a variety of ways that microbes evade host immune defense mechanisms. Antigenic ___________ occurs when the pathogen changes surface antigens to remain undetected by the host immune system.
variation
Which virus results in shingles when it is reactivated with peripheral nerves?
varicella-zoster
Which virus is responsible for Grandfather Davis's shingles?
varicella-zoster virus
Which mode of transmission is not addressed by transmission precautions?
vector
HIV-positive mothers can transmit the virus through breastfeeding. This is considered __________ transmission.
vertical
Which type of molecule can diffuse through the blood-brain barrier?
very small molecules and lipophilic molecules
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.
The upper respiratory tract is lined with mucous membranes which secrete mucous. What is the purpose of mucous?
warms and humidifies, and traps microbes and debris from the air we breathe
In a dehydration synthesis reaction, macromolecules are built when ________ is removed to form a covalent bond.
water
Localized anaphylaxis tends to feature isolated symptoms such as
watery eyes, a runny nose, or a confined rash.
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
Which of the following factors would NOT contribute to the development of severe dermatomycoses?
wearing sandals
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.
Epidemiology is defined as the study of
where and when a disease occurs, and how it is transmitted.
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
DNA microarrays reveal
which genes are being expressed in a given cell.
Which of the following infectious disease transmission modes is not correctly paired with an example?
windborne: cholera
Proteins provide cells with the necessary equipment to perform normal cellular activity. Without gene expression the cell __________.
would die
A Gram stain is performed on a bacterial sample and the result for Step 1 is a Gram positive organism. According to the key, which step would you go to next?
you would go to step 2
The demographic most at risk from respiratory syncytial virus are
young children.
All of the following are anti-HIV drugs except ____________.
zanamivir
What is the word used to refer to diseases transmissible from animals to humans?
zoonoses