Microbiology 2021
According to the animation, surgical infections account for what percentage of nosocomial infections? 15% 11% 8% 40% 20%
20%
A microorganism is 20 um in size. What is its size in nm? Your answer must be numeric with unit such as 100 nm or 1,000 nm. Type a space between the number and the unit.
20000 nm
________ immunity is the vertebrate's ability to recognize and then mount a defense against specific invaders and their products.
Adaptive
(Q) Which of the following types of culture media would best be used by a veterinarian to grow any bacteria in a blood sample? A. selective and differential media B. general purpose media C. enrichment media D. selective media
Answer: C. Enrichment media
Match the parts to their functions
Ribosomes A. for protein synthesis Nucleus B. contains the cell's genetic instructions (DNA) Endoplasmic reticulum (smooth and rough) C. for transport of substances within the cell Golgi bodies D. receives, processes and packages large molecules for export
Below are groups of protozoa and their structures for movement. Which of the following is mismatched?
Sporozoa - spores
What ensures that the single strands of DNA do not come back together?
Stabilizing proteins
A reaction that involves the transfer of electrons from one molecule to another is referred to as
a redox reaction.
A bacterial genome is typically
a single circular DNA molecule.
The primary immune response involves
a slow rise in the concentration of antibodies, followed by a gradual decline.
A microarray is assembled using 58) ______ A) reverse transcriptase and DNA polymerase. B) single-stranded DNA and silicon chips. C) agarose and nitrocellulose. D) restriction enzymes. E) gold beads and magnets.
b
DNA encoding a normal gene is inserted into cells from a patient with a defective form of the gene. Recombinant cells are identified and isolated, and returned to the patient's body. This is an example of a. biotechnology. b. gene therapy. c. genetic fingerprinting. d. genomics. e. genotyping.
b
If all the following DNA fragments were analyzed on an electrophoresis gel, which one would migrate farthest from the negative electrode? 9) _______ A) 2500 base pairs B) 250 base pairs C) 1000 base pairs D) 5000 base pairs E) 750 base pairs
b
In Southern blotting, DNA molecules are immobilized on 46) ______ A) gold beads. B) nitrocellulose membranes. C) silicon chips. D) agarose. E) paper.
b
Which technique would be useful for locating a particular gene in living cells? a. PCR b. FISH c. DNA microarrays d. Next-generation sequencing
b. FISH (fluorescent in situ hybridization)
Which of the following is NOT involved in the process of DNA fingerprinting? a. using PCR to make multiple copies of a DNA sample b. addition of fluorescent nucleotides to a DNA sample c. gel electrophoresis of DNA fragments d. cutting a DNA sample with restriction enzymes
b. addition of fluorescent nucleotides to a DNA sample
Some ________ use group translocation as a means of transport.
bacteria
The drugs polymixins are effective against what group of microorganisms?
bacteria
Which of the following is a product of recombinant DNA technology
bacteria that produce insulin
Beta-lactam antibiotics have an effect on which of the following types of cells?
bacterial cells
Beta-lactam antibiotics such as penicillins, have an effect on which of the following types of cells?
bacterial cells
Which of the following groups of microorganisms can grow in the presence of oxygen but do not use oxygen to harvest energy or make ATP?
aerotolerant anaerobes
The use of microbes to make practical products such as vaccines or hormones is called (genomics/recombination/biotechnology).
biotechnology
The use of microorganisms to produce useful products is known as
biotechnology
A procedure using both reverse transcriptase and real time PCR can be used to
both determine the number of copies of an RNA sequence in a sample and produce fragments for cDNA cloning.
What is the function of the high temperature step in PCR (polymerase chain reaction)?
break hydrogen bonds for strand separation
Antibiotics used for life threatening diseases are the (narrow / broad) spectrum antibiotics.
broad
How does yeast reproduce asexually?
by binary fission
Which of the following items is NOT a part of the name of a restriction enzyme? a. Roman numerals to indicate its order of discovery b. the genus of the source bacterium c. the Gram reaction of the source bacterium d. the specific epithet of the source bacterium e. the strain of the source bacterium
c
Which of the following procedures might be used to detect the presence of genetic sequences of a virus in a sample? 16) ______ A) Southern blotting B) genome mapping C) Southern blotting or PCR D) creation of a gene library E) PCR
c
Which of the following procedures would be used to introduce DNA into a single mouse cell? a. electroporation b. gene gun c. microinjection d. protoplast fusion e. Southern blotting
c
Put the following steps of bacterial specimen preparation and staining in order: a. fixation b. application of staining dyes c. smear preparation
c, a, b
Put the following events in the construction of a recombinant DNA molecule in the correct order: a. ligation of desired gene to plasmid DNA b. introduction of the plasmid into bacteria c. restriction enzymes cut gene of interest and plasmid DNA d. growth of cells on an antibiotic-containing medium
c, a, b, d
The Hepatitis B vaccine is which type of vaccine?
Subunit vaccine
How are superantigens different from other types of exotoxins?
Superantigens cause an overstimulation of the host immune system
What is a superinfection?
Superinfection is a disease caused by an organism that is often an opportunist or one that was present in low numbers. Superinfection is a sequel to removal of the normal flora by antibiotic treatment.
Which type of active transport protein moves two molecules into the cell at the same time?
Symport
________ are used in the detection of DNA by FISH.
Synthetic DNAs and fluorescent tags
An antigen that is potent enough to activate a B cell on its own is known as
T-independent antigens.
Which receptor on the helper T-cell recognizes the specific antigen from an antigen-presenting cell?
TCR
Natural killer cells are activated by
TH1 cells.
Reverse transcriptase synthesizes a DNA molecule from an RNA template
TRUE
Southern blotting is a technique that can be used to identify microbes that cannot be cultured.
TRUE
The goals of recombinant DNA technology include production of new organisms with useful combinations of traits.
TRUE
The microbes residing on human skin are part of the human microbiome.
TRUE
Capsomere
The protein molecules that form the capsid.
Which are true statements about a DNA molecule?
The strands composing the DNA molecule are held by hydrogen bonds. It is composed of two strands. The two strands are complementary to each other; adenine-thymine and cytosine-guanine.
Which of the following genetic elements is transcribed into a single mRNA
The structural genes
Viral Enzymes Needed by RNA
They have single or double strands, and single strands can be negative or positive. In all cases, RNA viruses use a template strand of RNA to make a new viral genome. Single stranded RNA must bring in their own genomes that encode for dan polymerase.
What is the function of the connector proteins?
They link the leading strand DNA polymerase and the lagging strand DNA polymerase together
Quinolones and fluoroquinolones act against what bacterial target? Metabolic pathways unique to bacteria Cell membranes Bacterial ribosomes Cell walls DNA gyrase
DNA gyrase
Which enzyme breaks the hydrogen bonds during replication?
DNA helicase
Which of the following enzymes is responsible for "unzipping" a DNA molecule in preparation for its replication?
DNA helicase
What attaches the target gene to a desired location?
DNA ligase
The process known as PCR involves the use of
DNA polymerase.
Which statement best describes the human immunodeficiency virus (HIV) that has been shown to cause AIDS in humans?
HIV is an enveloped, positive single-stranded RNA (+ssRNA) virus of the type called retroviruses.
Microbial growth in jellies is inhibited by the (acidic/hypotonic/hypertonic) condition of the food.
HYPERTONIC
The first complete gene map was that of
Haemophilus influenzae.
What is the overall function of the trp operon?
To ensure that the cell has a supply of tryptophan at all times
Lazzaro Spallanzani was the first scientist to provide evidence disproving the spontaneous generation of microorganisms.
True
Louis Pasteur is considered the Father of Microbiology because of the many carefully conducted experiments and observations he made with microbes.
True
Which transport protein employs transporters that move molecules only in one direction?
Uniport and Symport
A researcher finds a mutant mouse with a phenotype that may have applications to human disease. What would be the most efficient means of identifying the mutated gene? a. Use a microarray to identify transcribed genes. b. Use DNA fingerprinting to identify a DNA fragment of altered size. c. Use DNA fingerprinting to identify an altered DNA fragment, sequence it and search a gene library. d. Search a mouse gene library. e. Sequence the entire genome of the mutant.
Use DNA fingerprinting to identify an altered DNA fragment, sequence it and search a gene library.
What is the function of the conjugation pilus?
It pulls the F+ and F- cells together.
What is the function of the parental DNA in replication?
It serves as the template for DNA replication.
Which of the following is NOT a reason why human proteins can be synthesized in bacteria or yeast through genetic engineering?
NOT: The protein produced by microbes works better than the original protein. CORRECT: A. There is no risk of accidentally transferring pathogens. B. This approach is usually less expensive than traditional methods. C. Large quantities of the protein can be made easily.
When a person has previously been vaccinated against a viral pathogen, which cells are activated if that same pathogen re-enters the host's cells months or years later?
Memory cytotoxic T cells
Meningitis and gonorrhea are caused by Neisseria species. Pseudomonas species. measles virus.
Neisseria species.
Compare and contrast three metabolic pathways by choosing whether the statement applies to aerobic respiration. Check all that apply.
Process involves the Krebs cycle End products are CO2 and H2O Process involves electron transport and chemiosmosis A total of 38 ATP are produced per molecule of glucose input. Process includes glycolysis The coenzyme NAD+ plays an important role in the pathway. Much or most of the ATP produced is produced by oxidative phosphorylation
Lytic Infections
Produce the most new viruses
How do mucous membranes protect the body?
Mucous membranes continuously shed cells with attached microbes.
A patient has been diagnosed with a disease caused by a drug-resistant strain of bacteria. What is a likely way that the bacterium initially acquired resistance?
Mutation
This activity requires that you sort cell structures according to whether they are found in prokaryotic cells or eukaryotic cells. Drag each of the following terms into the appropriate box, indicating whether it applies to prokaryotic cells or eukaryotic cells.
Prokaryotic cells Circular chromosome, not enclosed within a nuclear envelopePeptidoglycan-containing cell wall70s ribosomesFlagella that rotate, composed of flagellin Eukaryotic cells Linear chromosomes enclosed within a nuclear envelopeCellulose or chitin-containing cell wallFlagella that wave, composed of microtubulesGolgi apparatusLysosomesMitochondria80s ribosomesEndoplasmic reticulum Submit
How can health care workers reduce the occurrence of nosocomial infections? Administer all medications orally instead of through injections Practice more stringent aseptic techniques Limit the number of visitors who can see the patient Reduce the number of times they visit a patient
Practice more stringent aseptic techniques
Capsid
Protein shell surrounding nucleic acid
What cellular macromolecules make up the complement pathway?
Proteins
What is the color of Gram-negative bacteria after application of decolorizer? It is a one-word answer and spelling matters.
colorless
CC: The restriction enzyme EcoRI is used in recombinant DNA technology to _______________.
cut DNA at a specific palindromic sequence of N-bases.
An effective tool for screening a large number of genetic sequences at once is known as a. cDNA synthesis. b. FISH. c. gel electrophoresis. d. microarray. e. restriction analysis.
d
DNA encoding a normal gene is inserted into cells from a patient with a defective form of the gene. Recombinant cells are identified and isolated, and returned to the patient's body. This is an example of 57) ______ A) genotyping. B) biotechnology. C) genomics. D) gene therapy. E) genetic fingerprinting.
d
DNA fingerprinting can be used 41) ______ A) to detect unculturable organisms. B) to generate cDNA clones. C) to generate cDNA clones and libraries. D) for forensics and detection of unculturable organisms. E) in forensic investigations.
d
In gel electrophoresis, DNA molecules move toward the ____ electrode(s) because they have an overall ____ charge. a. negative; negative b. negative; positive c. negative and positive; neutral d. positive; negative e. positive; positive
d
Small circular DNA autonomously replicating molecules with several restriction sites and a "marker" to trace their location are commonly called a. arrays. b. clones. c. phages. d. vectors. e. vehicles.
d
The DNA double helix can be separated into single strands using a. heat. b. NaOH. c. reverse transcriptase. d. either heat or NaOH. e. heat, NaOH, and reverse transcriptase.
d
What function do restriction enzymes perform? a. They read mRNA and write cDNA. b. They replace RNA with DNA on a lagging strand. c. They splice DNA into a lagging strand. d. They cut DNA at specific sequences.
d. They cut DNA at specific sequences.
What process is used to "amplify" DNA, making large numbers of copies from a small sample? a. priming b. gene libraries c. thermocycler d. polymerase chain reaction
d. polymerase chain reaction
Which viral enzyme is used to copy nucleotide sequences to make cDNA? a. helicase b. DNA ploymerase I c. DNA polymerase III d. reverse transcriptase
d. reverse transcriptase
Pus is comprised of
dead phagocytes.
A nurse preparing a section of skin for an injection is an example of __________.
degerming
Boiling kills microorganisms by
denaturation of proteins
Endospores survive a variety of harsh conditions in part because of the presence of
dipicolinic acid.
________ are used in the detection of DNA by FISH. 3) _______ A) Reverse transcriptase and DNA polymerase B) DNA polymerase and DNA ligase C) Compressed air and gold beads D) Restriction fragments E) Synthetic DNAs and fluorescent tags
e
Semiconservative DNA replication means that
each daughter DNA molecule is composed of one original strand and one new strand.
The DNA double helix can be separated into single strands using a. either heat or NaOH. b. heat. c. NaOH. d. heat, NaOH, and reverse transcriptase. e. reverse transcriptase.
either heat or NaOH
Protoplasts are associated with which of the following?
electroporation
What is one method by which you could insert DNA from one cell into another cell?
electroporation
A disease that is constantly present in a population at low numbers is a(n) __________. pandemic outbreak endemic epidemic
endemic
Protozoa, fungi, bacteria, and viruses that reproduce inside a body's cells produce what type of antigens?
endogenous antigens
Which of the following types of toxins are produced only by Gram-negative bacteria?
endotoxins
Which of the following could be used to sterilize objects such as medical devices?
ethylene oxide
Identify the type of hypersensitivity reaction in each photograph. Drag the appropriate labels to their respective targets.
eye: type III (SLE) bump on arm: type IV (+ TB) hands: type III (RA) rash: type I (urticaria)
Gene therapy for human genetic diseases has not been successful yet.
f
It is the increase in body temperature above 37°C due to the presence of pyrogens. It is a one-word answer and spelling matters.
fever
What are the clinical signs and symptoms of typhoid fever?
fever and rose-spotted rash
Julie goes to the hospital for a surgery that will require receiving blood from a donor. She is blood type O, but a mix up in the paperwork results in blood type B entered on her forms. During surgery she received 2 units of blood, type B. After surgery she may experience __________.
fever, difficulty breathing, nausea, and vomiting
Pyrogens are ________.
fever-inducing substances
The filament and basal body are associated with which of the following external structures found in some bacterial cells?
flagella
If a scientist wanted to view the location of a particular species of bacterium within a biofilm, which technique could be used?
fluorescent in situ hybridization (FISH)
Which of the following cells is a component of the body's first line defense?
goblet cell
Staphylococcus aureus is a particularly dangerous organism when in food due to the enterotoxins some species produce. These toxins are dangerous because they are __________. acid-tolerant heat-stable superantigen toxins heat-stable, acid-tolerant superantigen toxins
heat-stable, acid-tolerant superantigen toxins
The destruction of blood cells leads to the release of large amounts of _____, which is then degraded into bilirubin.
hemoglobin
hat is the relationship of optical density (OD) to the concentration of cells in a broth culture?
high OD > high concentration of cells
chapter 16
homework
How wold one increase the concentration of a particular polypeptide in a cell?
increase the level of transcription
Which of the following is the most important part of sterilization using an autoclave?
increased pressure
Which of the following is the most important part of sterilization using an autoclave?
increased pressure While all of these are important aspects of autoclaving as a sterilization procedure, it is the increased atmospheric pressure inside the autoclave that makes the increase in steam temperature possible. This increase in pressure also reduces the time needed for sterilization.
Fever is beneficial during viral infection because the higher temperature
increases the effectiveness of interferons.
What do we call the person determined to be the first case of a disease in an outbreak?
index case
Pasteur's experiments on fermentation laid the foundation for
industrial microbiology.
Staphyloccocus aureus is an important cause of food poisoning. Several gene-encoding exotoxins are associated with S. aureus food poisoning, including SEA, an exotoxin encoded by a viral gene. What sort of life cycle must this phage have? lytic cytocidal infections budding lysogenic
lysogenic
Which of the following organelles breaks down worn-out organelles?
lysosomes
A series of vesicles are formed before, during, and after phagocytosis; the first vesicles formed are
lysosomes.
What is the antibacterial enzyme present in our sweat? It is a one-word answer and spelling matters.
lysozyme
What carries instructions for making proteins from the nucleus into the cytoplasm?
mRNA
Which of the following can be translated into protein?
mRNA
Which of the following best describes the flow of information in cells?
mRNA is made by copying specific regions of DNA called genes. Ribosomes use mRNA as instructions, which provide a code specifying the order of amino acids in a protein.
Transcription produces which of the following?
mRNA, tRNA, and rRNA are all produced by transcription
An adaptive immune response is able to generate faster and more effective responses in subsequent encounters with a particular pathogen or toxin. This description is what attribute of adaptive immunity. It is a one-word answer and spelling matters
memory
The tuberculin response is mediated by
memory T cells.
Which of the following represent the majority of pathogenic bacteria?
mesophiles
As shown in the animation, the start codon also codes for which amino acid?
methionine
A DNA (library/microarray/screen) may be used to study the complex, changing patterns of mRNA production in an organism.
microarray
An effective tool for screening a large number of genetic sequences at once is known as
microarray.
Which of the following is NOT an example of symbiosis?
microbes crossing the placenta to the fetus
Which of the following is a product of recombinant DNA technology?
microbes that produce vitamins, insulin and vaccines
The insertion of foreign DNA directly into a cell's nucleus using a glass micropipet is called (electrophoresis/electroporation/microinjection).
microinjection
The insertion of foreign DNA directly into a cell's nucleus using a glass micropipette is called ________.
microinjection
Where in a cell is ATP made?
mitochondira
DNA in bacteria is located in the region called ________. It is a one-word answer and spelling matters.
nucleoid
Where is the genetic information of the cell stored?
nucleus
The ability of a lens to gather light is referred to as its
numerical aperture
A microbe that grows only at the bottom of a tube of thioglycollate medium is probably a(n)
obligate anaerobe
The diffusion of water molecules across a plasma membrane is called ________. It is a one-word answer and spelling matters.
osmosis
The most commonly used isolation technique in microbiology laboratories is the __________.
streak-plate method
In a hypotonic environment, the vacuole of a plant cell enlarges and pushes the cytoplasm against the cell wall. Which organelles are most likely able to store that extra water?
vacuoles
Which of the following is NOT a beta-lactam antibiotic?
vancomycin
Which of the following is NOT a feature associated with filtration?
varying thicknesses of membrane filters used
TRANSDUCTION PICTURES
vertical picture with phages
The ________ method provides an estimate of the CFUs (colony-forming units) in a sample.
viable plate-count
Certain traits that allow pathogens to create infection and cause disease are termed
virulence factors
Certain traits that allow pathogens to create infection and cause disease are termed streptokinases. collagenases. virulence factors. hyaluronidases
virulence factors
Growth occurs in all except in ________.
viruses
Viral envelopes are formed when?
when the virus leaves the host cell
Epidemiology is defined as the study of how a disease is transmitted. where and when a disease occurs, and how it is transmitted. where a disease occurs. when a disease occurs.
where and when a disease occurs, and how it is transmitted.
The process of introducing animal organs into the human body is
xenotransplantation.
~*~*~*QUIZ*~*~*~
~*~*~*QUIZ*~*~*~
You have just started brewing beer at home, and your first batch is now ready. You used the yeast Saccharomyces cerevisia, which can perform both aerobic cellular respiration and fermentation. When you test the beer, you determine that the alcohol content is almost zero. What could have been present in the fermentation reaction apparatus that caused this problem?
oxygen
PCR stands for
polymerase chain reaction
Which of the following processes is used to "amplify" DNA, making large numbers of copies from a small sample?
polymerase chain reaction
In gel electrophoresis, DNA molecules move toward the ________ electrode because they have an overall ________ charge.
positive; negative
What is the filamentous structure formed by some species of yeasts?
pseudomycelium
Semmelweis advocated handwashing as a method of preventing which of the following diseases?
puerperal fever
During the 2002-2004 emergence and epidemic of Severe Acute Respiratory Syndrome corona virus (SARS-coV) the virus was found to be highly contagious, with an observed reproductive number (R) of 3.6. For this reason many rigorous means of infection control were instituted by the countries experiencing SARS outbreaks, including__________. culling of chickens. vaccination. quarantine and isolation. application of DDT to kill mosquitoes.
quarantine and isolation
Which of the following is a low-level disinfectant?
quats
Ribosomes contain which of the following?
rRNA
What is the target structure of tetracycline?
ribosome
One of the ways smooth endoplasmic reticulum (ER) differs from rough endoplasmic reticulum is that rough ER is covered by
ribosomes
Tumbles occur when the flagella
rotate clockwise
Genetic (screening/sequencing/cloning) can be used to detect mutant genes associated with genetic diseases in individuals before any clinical symptoms are noted.
screening
A culture medium that favors the growth of one group and inhibits the growth of another group is called ________.
selective culture medium
Which type of media is used to prevent the growth of certain microbes while allowing the growth of others?
selective media
Drugs that cannot be given orally are those drugs that are (sensitive / not sensitive) to acid pH.
sensitive
Mice that are injected with only the R strain of Streptococcus pneumoniae
stay healthy, because their immune systems can kill this strain easily.
RNA that has hydrogen bonded to itself forms a
stem loop
Which microorganism requires the low pH inside a phagolysosome in order to reproduce?
Coxiella burnetii
RNA viruses synthesize their nucleic acid in the host cell(s)...?
Cytoplasm
Where does transcription occur in prokaryotes?
Cytoplasm
Refrigeration is an effective germicidal method.
FALSE
Restriction enzymes are useful only on synthetic DNAs.
FALSE
Scientists were able to increase the production of naturally occurring vitamin A in rice plants.
FALSE
Sticky-end fragments generated by EcoRI will hydrogen bond to any other sticky-end sequence.
FALSE
The human microbiome is very uniform across the entire species Homo sapiens in all geographic locations.
FALSE
Sticky-end fragments generated by EcoRI will hydrogen bond to any other sticky-end sequence.
FALSE; sticky-ended fragments bind only to complementary, sticky-ended fragments produced by the same restriction enzyme
How do stabilizing proteins work on the DNA?
They bind to the single-stranded DNA
What connects layers of peptidoglycan to each other? It is a one-word answer and spelling matters
tetrapeptides
When a transducing phage interacts with a new host cell,
the DNA from the previous host can recombine with the new host chromosome
When a transducing phage interacts with a new host cell,
the DNA from the previous host can recombine with the new host chromosome.
If a patient notices a healthcare worker not following suggested precautions,
they should immediately bring it to the attention of the healthcare worker.
The heavy metal compound ________ is used as a preservative in some vaccines.
thimerosal
The line of defense that involves lymphocytes and antibodies is the (first / second / third) line of defense.
third
Clonal deletion occurs in the __________.
thymus
Which of the following are primary lymphoid organs in humans?
thymus bone marrow
In the laboratory, recombinant DNA technologists use restriction enzymes __________.
to cut specific genes from one organism for the purpose of inserting the genes into the DNA of another organism
In the laboratory, recombinant DNA technologists use restriction enzymes __________.
to cut specific genes from one organism for the purpose of inserting the genes into the DNA of another organism Submit
If an anti-A serum is shown in this agglutination test, then the patient's blood contains A antigens.
true
Reverse transcriptase synthesizes a DNA molecule from an RNA template.
true
Southern blotting is a technique that can be used to identify microbes that cannot be cultured.
true
The goals of recombinant DNA technology include production of new organisms with useful combinations of traits.
true
The microbes resident on human skin are part of the human microbiome.
true
Under ideal conditions, the number of DNA molecules produced during PCR increases exponentially.
true
What is the basic function of the lac operon?
To code for enzymes involved in catabolizing lactose.
(Q) Which enzyme catalyzes the reaction: 2H2O2 → 2H2O + O2? A) Catalase B) Oxidase C) Peroxidase D) Superoxide dismutase
Answer: A) Catalase
Axial filaments are found on
spirochetes.
(Q) Most bacteria reproduce by: A) binary fission. B) fragmentation. C) mitosis. D) aerial hyphae. E) budding.
Answer: A) binary fission.
Differentiate diffusion from facilitated diffusion.
Diffusion does not need transport protein while facilitated diffusion needs transport protein.
A technique using fluorescent-tagged probes to detect specific DNA sequences in their natural locations is known as (FISH/PCR/BLOTTING).
FISH
Michelle wants to know which cells in a particular organ produce a specific gene product. She has a cDNA clone of the gene available. What method would be the most useful to answer this question?
FISH (fluorescent in situ hybridization)
Which of the following does NOT happen above the maximum growth temperature of a microorganism?
Membranes become rigid and fragile.
Where are MHC molecules located on a cell?
On the surface of the cell
According to the animation, which of the following makes mRNA from the information stored in a DNA template?
RNA polymerase
When the cell is NOT in the presence of tryptophan,
RNA polymerase can transcribe mRNA.
(Q) The source of nutrients in nutrient agar is: A) Agar. B) Nutrient. C) Peptone and beef extract. D) Peptone and NaCl.
Answer: C) Peptone and beef extract.
(Q) T or F: Filtration methods are used to count bacteria present in very low concentrations, such as in lakes and streams.
Answer: True
(Q) T or F: Nitrogen-fixing bacteria, such as cyanobacteria, can use atmospheric nitrogen (N 2 ) for their nitrogen source.
Answer: True
How do the strands separate during PCR?
The high heat of the denaturation step breaks the hydrogen bonds between the two strands
How do the strands separate during PCR?
The high heat of the denaturation step breaks the hydrogen bonds between the two strands.
Acidic stain has ________ charge chromogen and forms ionic bond with ________ charge part of the cell.
negatively ; positively
What new technology increases the precision of gene editing, and may make gene therapy easier? CRISPR-Cas9 FISH next-generation sequencing microarrays PCR
CRISPR-Cas9
Spirillum have wider spirals due to their flexible cell walls and spirochetes have narrower spirals due to their rigid cell walls.
False
Where could a research scientist find copies of all the genes of a microbe without having to isolate them from the microbe?
Gene library
Which of the following would not be a potential medical application of recombinant DNA technology: gene library, genetic mapping, gene therapy, xenotransplantaton?
Gene library
What is considered to be the average natural mutation rate that occurs during DNA replication?
One in every billion nucleotides replicated.
How often do silent mutations occur?
One out of every three mutations
Which statements are true about pilus?
Only one or two are present per cell. It is shorter than flagellum. It is longer than fimbriae.
The presence of which of the following can substitute for nitrogen fertilizers in legume crops? Rhizobium Bacillus Clostridium Azotobacter
Rhizobium
How does RhoGAM prevent hemolytic disease of the newborn?
RhoGAM attaches to Rh antigen, leading to its removal before the mother's immune system mounts an adaptive response.
Which finding is most surprising from Griffith's experiments?
S strain cells are isolated from the blood of mice infected with heat-killed S strains and live R strains.
What happens to the packaged DNA of a specialized transduced phage when it infects a new recipient cell?
The host DNA integrates, with the prophage, into the new recipient chromosome.
How does specialized transduction differ from regular lysogeny?
The prophage in specialized transduction carries with it pieces of the host chromosomal DNA.
Autotrophs are organisms that use CO2 as source of carbon (can photosynthesize) while heterotrophs are organisms that use organic carbon as source of carbon.
True
DNA fingerprinting produces a unique banding pattern of DNA fragments for comparison with other DNA samples.
True
TRANSFORMATION
-requires the recipient cell to be competent -Naked DNA is transferred from donor to recipient
Label the parts of the B cell receptor. Drag the appropriate labels to their respective targets.
...
Match the key terms and concepts of the immune system with their descriptions.
...
Which of the following is a true statement concerning bacteria and archaea?
While some bacteria are pathogenic to humans, no archaea are known to cause human diseases.
What results from the process of translation?
a polypeptide
Which of the following is not involved in the process of DNA fingerprinting?
addition of fluorescent nucleotides to a DNA sample
Which of the following is generally NOT considered an ethical issue regarding recombinant DNA technology?
answering basic research ques
Rabies is an example of a zoonosis that is hard to control because __________.
its reservoir contains both domestic and sylvatic animals
Air-dried bacterial smears are passed in the flame of the Bunsen burner 3-4 times in order to ________.
kill and attach the cells on the slide
Put the following events of bacterial conjugation in order. 1) fusion of cell membrane 2) attachment of sex pilus 3) transfer of F factor 4) pulling of donor and recipient cells together
2-4-1-3
What structure acts as a selective barrier, regulating the traffic of materials into and out of the cell?
plasma membrane
Synthesis of cDNA requires the use of a. reverse transcriptase. b. agarose. c. DNA ligase. d. restriction enzymes. e. fluorescent synthetic nucleotides.
reverse transcriptase.
Which of the following recombinant tools is NOT used in DNA fingerprinting?
reverse transcription
A new arrow labeled "lengthens" could be added between __________.
"Taq polymerase" → "primers"
In vitro means
"within glassware."
Both bacteria and archaea are prokaryotes and unicellular. What is the difference between them?
Cell wall composition of archaea is different from the cell wall composition of bacteria.
An antibiotic that inhibits cell wall synthesis will result in which of the following?
Cells become more susceptible to osmotic pressure.
BOTH TRANSCRIPTION AND TRANSLATION
-mRNA
Module Quiz
5
Newly formed virus can be released from the cell by which of the following?
A. Budding C. Cell Lysis
Animal Viruses can have any of the following types of nucleic acids except...?
A. Double-stranded RNA B. Single-stranded RNA C. Single-strands of RNA or DNA*** D. Single-stranded DNA E. Double Stranded DNA C
During events associated with penetration and attachment theses are ALL true.
A. Viruses can share host cells receptors B. Virus/receptor interactions facilitate the infection process C. Host cell receptors used by viruses represent a large portion of the cell membrane proteins D. For enveloped viruses, fusion occurs between the viral envelop and the host cell membrane E. Fusion is facilitated by specialized fusion proteins
Viruses can spread through which of the following methods?
A. Fusion of the host cell with a neighbor cell B. The formation of syncytia C. The rupture of the host cell ALL OF THE ABOVE
Viral structures can contain any of the following EXCEPT?
A. capsomeres B. a capsule C. an envelop D. a capsid B
Why is ATP necessary for active transport?
ATP provides energy to transfer material against its concentration gradient.
Which of the following would be useful as part of the drug cocktail ART taken to treat HIV infections?
AZT, a nucleoside compound
Which of the following is a characteristic of an F+ cell?
Ability to synthesize sex pili, presence of a fertility factor, and ability to mate with an F- cell.
Explain why is adding high amount of salt and sugar prevent food spoilage caused by microorganisms?
Adding high amount of salt and sugar creates a hypertonic environment to microorganisms. The process removes water from microorganisms killing them.
Which of the following has been genetically modified to stop the spread of a human disease? a. Pseudomonas b. Bacillus thuringiensis c. Haemophilus influenzae d. Aedes aegypti e. Thermus aquaticus
Aedes aegypti
When do helper T-cells develop into TH1 or TH2 cells?
After proliferation into a clonal population
What amino acid is carried by the tRNA illustrated below? It is a three-letter word such as Phe.
Ala
(Q) A microbe reproduces by binary fission every 20 minutes under favorable conditions. How long would 10 generations take and how many bacteria would be present if all the conditions were just right? (1) 18 hours and 40 minutes, producing 1 million bacteria (2) 3 hours 20 minutes, producing 1,024 bacteria (3) 2 hours and 10 minutes, producing 1,048,576 bacteria (4) 24 hours, producing 262,144 bacteria
Answer: (2) 3 hours 20 minutes, producing 1,024 bacteria. Extra: The organism produced 210 over 10 generations, which would take a little over 3 hours and produce over a half million bacterial cells.
Baking bread, creating a genetically modified vegetable, using a microbe to make human insulin . . . Which of these is NOT considered "biotechnology"? Baking bread Using a microbe to make human insulin All of these are biotechnology Creating a GMO vegetable
All of these are biotechnology
Match the given protozoa to their locomotive structures.
Amoeba proteus C. pseudopodium Blepharisma americana A. cilia Peranima sp. D. flagella
Which of these antibiotics can be used to treat the infection caused by Micrococcus luteus? Assume that the antibiotics diffuse at the same rate, are equally safe and easily administered. Write correct spelling of the antibiotic
Amoxicillin
What is the key difference between donor cells and recipient cells?
An F plasmid
what is the key difference between donor cells and recipient cells?
An F plasmid
What type of ABO blood group antibodies does a person with blood type B typically have?
Anti-A antibodies
When are anti-Rh antibodies developed by the adaptive immune system?
Anti-Rh antibodies are produced after exposure to the Rh antigen.
Which type of active transport protein uses one protein to pump two different molecules?
Antiport and Symport
Why is a specimen smaller than 200 nm not visible with a light microscope?
Anything smaller than 200 nm cannot interact with visible light.
Attachment 2/2
Attachment occurs when s a vision binds to specific receptors Some cells require a co-receptor to attach, and without a co-receptor, they can't infect host cell.
All are illustrating microbial antagonism between normal flora and pathogen except ________.
Attachment of normal flora is blocked by pathogens
Which type of vaccine could possibly cause a person to develop the disease?
Attenuated live vaccine
TH2 cells produce cytokines that activate
B cells.
Which domain of the A-B toxin binds to cell surface receptors on the host cell?
B domain
What lymphocytes transform into antibody-producing cells?
B lymphocytes only
Which of the following microbes produces a protein that kills a variety of insect pests?
Bacillus thuringiensis
Which of the following microbes produces a protein that kills a variety of insect pests? Plasmodium falciparum Pseudomonas Thermus aquaticus Haemophilus influenzae Bacillus thuringiensis
Bacillus thuringiensis
The figure represents a Petri plate. The gray area is where bacteria A is growing, the black area is where bacteria B is growing. The white area is a zone where neither organism is growing. What is the best interpretation of what is observed on the plate?
Bacteria B is producing an antibiotic that inhibits the growth of bacteria A.
How is bacterial translation different from eukaryotic translation?
Bacteria can begin translation before transcription has terminated.
Which of the following situations is not a way in which a baby acquires his normal flora?
Bacteria cross the placenta during pregnancy.
Which of the following statements concerning sugar utilization in E. coli is true?
Bacteria growing on glucose as the sole carbon source grow faster than on lactose
An antimicrobial that inhibits bacterial cell wall synthesis will result in which of the following?
Bacterial cells become more susceptible to osmotic pressure.
All of the following are Gram-positive genera typically found on the skin EXCEPT __________. Propionibacterium Bacteroides Staphylococcus Corynebacterium
Bacteroides
Which of the following defensive cell types is not phagocytic?
Basophils
Why are Gram-negative (G-) bacteria more resistant to antimicrobial agents than Gram-positive (G+) bacteria?
Because G- have an outer membrane.
What is the function of the CD8 receptor?
Bind to MHC molecules
What is the function of boosters?
Boosters are injections that are given periodically to maintain immunity.
How does water enter and exit a cell?
By simple diffusion or by use of an integral transport protein
The skin and the mucous membranes are similar in which of the following aspects?
Both have epithelial cells packed closely together.
Which molecule shown in the animation, the square or the circle, is moving against its concentration gradient?
Both the circle and the square
Based on the animation, which of the following is cleaved by C1?
C2 and C4
Based on the animation, which of the following is responsible for cleaving C3?
C2aC4b
In the classical pathway, which of the following directly activates cellular responses?
C3a, C5a, and C5bC6C7
Based on the animation, which of the complement proteins can directly bind to the surface of a bacterial cell?
C3b
What causes thrush?
Candida albicans
Icosahedral Virus
Capsid arrangement seen in some viruses in which there are 20 geometric sides that make up the virus protein coat.
How can capsules enable bacteria to evade the immune system?
Capsules block the complement biding sites on the surface of the pathogen.
What causes cell damage in a type III hypersensitivity?
Chemicals released by neutrophils.
What is meant by selective toxicity?
Chemotherapeutic agents should act against the pathogen and not the host.
What is meant by selective toxicity? Chemotherapeutic agents should work on certain types of pathogens. Chemotherapeutic agents should act against the pathogen and not the host. Chemotherapeutic agents should have only one mode of action. Chemotherapeutic agents should work on many different targets on a pathogen.
Chemotherapeutic agents should act against the pathogen and not the host.
Which of the following would you likely see on the surface of a human dendritic cell following phagocytosis of a bacterium?
Class I MHC with dendritic cell antigens and Class II MHC with engulfed bacteria
What is the term for three RNA nucleotides that code for a specific amino acid during polypeptide synthesis?
Codon
Which statement about conjugation is false?
Conjugation is a process of bacterial reproduction.
Why does conjugation between an Hfr strain and an F- strain not result in two Hfr strains?
Conjugation is typically disrupted before the fertility factor can be transferred.
Why does conjugation between an Hfr strain and an F- strain not result in two Hfr strains?
Conjugation is typically disrupted before the full copy of fertility factor can be transferred.
Match the terms with its description.
Contamination D. mere presence of microbes in or on the body Infection A. invasion of the host by pathogens Disease C. normal body functions are altered due to invasion by pathogens Etiology B. study of the cause of disease
Which of the following are likely to be found on an MHC-I protein?
Damaged mitochondrial fragment
Place the stages of maturation of the light organ in Euprymna scolopes in the correct order. A. migration to light organ B. monoculture of bacteria established C. reproduction of bacteriaD. mature light organE. mucus secretion by squid E, A, C, B, D E, C, A, B, D E, B, C, A, D E, B, A, C, D
E, B, A, C, D
Which of the following phagocytic processes occurs last in the sequence?
Exocytosis
Which of the following would not be a potential medical application of recombinant DNA technology: gene library, genetic mapping, gene therapy, xenotransplantaton? Genetic mapping Xenotransplantation Gene library Gene therapy
Gene library
What structural part of a bacterial flagellum is composed of flagellin?
Filament
Which of the following statements about bacterial flagella is true?
Flagella can rotate 360 degrees.
Penetration
For enveloped viruses, penetration occurs through a fusion event between the viral envelope and the host cells plasma membrane
A periplasmic space is found in which of the following?
Gram-negative cells only
If a microbiology lab student left the safranin out of the Gram stain procedure, what would be the result?
Gram-positive cells would be purple and Gram-negative cells would be colorless.
Clostridium difficile is a common healthcare associated infection. It is a Gram-positive spore-forming anaerobe that is associated with antibiotic therapy. It is most commonly transferred between patients on the hands of health care workers. Based on this information, rank the following prevention and control strategies from most beneficial (1) to least beneficial (4).
Hand hygiene with soap and water Use of gloves Use of approved chemical disinfectants in patient rooms Hand hygiene with alcohol gels
What is the mordant in endospore staining? It is a one-word answer and spelling matters.
Heat
Which chemical released during type I hypersensitivity responses causes contractions of smooth muscle, such as in the bronchi?
Histamine
Ch 1
Homework
Ch 3
Homework
Chapter 14
Homework
Which of the following enzymes breaks down the "glue" that holds cells together?
Hyaluronidase
What are the differences between hypersensitivity pneumonitis, rheumatoid arthritis, glomerulonephritis, and systemic lupus erythematosus?
Hypersensitivity pneumonitis is caused by foreign antigens, while rheumatoid arthritis and systemic lupus erythematosus are caused by autoantigens and glomerulonephritis can be caused by either foreign or autoantigens.
What combination of mother/child blood types might develop into hemolytic disease of the newborn?
If the mother is Rh- and the fetus is Rh+, this may lead to hemolytic disease of the newborn.
Which of the following antibodies is transferred to newborns through the mother's breast milk? Your answer is a three-letter word such as IgD.
IgA
What antibody triggers mast cells and basophils to release inflammatory chemicals, such as histamine, associated with allergies? Your answer is a three-letter word such as IgD.
IgE
Which type of antibody is involved in a type I hypersensitivity response?
IgE
Which of the following mediators are involved in anaphylactic reactions?
IgE Basophils mast cells
Where would one find an uncharged tRNA molecule in a ribosome?
In the P and E sites
Bacteriophages are viruses that?
Infect bacteria
What is electroporation used for?
Inserting DNA into cells
Which of the following molecules would be blocked by a cell membrane?
Ions
The Process of Reverse Transcriptase
Is very error-prone and it is during this step that mutations may occur. Such mutations may cause drug resistance.
What benefit does the F- strain receive from mating with an Hfr strain?
It acquires new, potentially beneficial genes from the Hfr strain.
According to the animation, how do the repressor proteins block the transcription of the structural genes?
It binds to the operator when activated.
What is the effect of immersion oil on resolution?
It decreases refraction of light. It increases numerical aperture. It increases resolution.
Why is the alternative pathway of complement useful in the early stages of an infection?
It does not rely on activation by antibodies.
Which of the following statements regarding the surface of the skin is FALSE?
It has goblet cells.
Why does immersion oil improve resolution?
It increases numerical aperture and maintains a uniform light speed.
Which of the following characteristics of a chromosome would identify it as a prokaryotic chromosome rather than a eukaryotic chromosome?
It is a circular molecule.
Eosin-methylene blue agar inhibits the growth of gram-positive organisms while allowing gram-negative organisms to grow. Colonies of lactose fermenters turn a blackish color while nonfermenters are colorless. How would you classify EMB? Is EMB a differential medium or a selective medium? Think about the meaning of the terms differential and selective to choose your answer. It is a differential medium and a selective medium. It is a selective medium only. It is neither differential nor selective. It is a differential medium only.
It is a differential medium and a selective medium.
What is the reason for the delayed response in a type IV hypersensitivity?
It takes macrophages and T cells time to travel to the site of the antigen.
A plasmid unexpectedly converts to a linear form inside a cell. What will happen to it?
It will be degraded by cellular enzymes
A plasmid unexpectedly converts to a linear form inside a cell. What will happen to it?
It will be degraded by cellular enzymes.
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 a virulence factor specific to Gram-negative pathogens?
Lipid A
Microbes in the __________ phase of the microbial growth curve are most susceptible to antimicrobial drugs.
Log
Which of the following types of bacterial cells would have flagella located at only one end of the cell?
Lophotrichous and monotrichous
A scientist develops a dye that changes from red to yellow when it is exposed to an acidic environment. If she uses the dye to stain a macrophage, which of these cellular organelles would be yellow?
Lysosome
How does lysozyme on the skin and in tears protect against bacterial pathogens?
Lysozyme breaks bonds in peptidoglycan in bacterial cell walls.
As shown in the animation, the start codon also codes for which amino acid?
Methionine
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 legionellosis contagious?
No. Legionellosis is not contagious.
Cookies have a water activity of 0.3. Can normal bacteria grow on this food? Support your answer.
Normal bacteria cannot grow on this food because the water activity is too low to support their metabolism.
Which requires a higher temperature and longer time to sterilize? Support your answer.
Oven sterilization because penetration of heat is slower due to absence of water.
Bacteria that are resistant to sulfonamide have enzymes that have a greater affinity for what?
PABA
Bacteria that are resistant to sulfonamide have enzymes that have a greater affinity for what? PABA Sulfonamide Tetrahyrdrofolic acid Tetracycline
PABA
How might efflux pumps increase antibiotic resistance in bacteria?
PABA
Which of the following describes opportunistic pathogen?
Pathogen that cause disease in person with weakened resistance.
Neutrophils are "first responders" during an inflammatory response. What is their specific role?
Phagocytosis
Which structure do antigen presenting cells utilize to directly help them present bacterial antigens?
Phagolysosome
How can health care workers reduce the occurrence of nosocomial infections?
Practice more stringent aseptic techniques
What is produced by the process of clonal expansion?
Plasma cells and memory B cells
Which of the following microbes has been genetically engineered to contain a protein that helps protect crops from freezing?
Pseudomonas
Why did the skin turn red and swell up?
Redness and swelling are due to the release of histamine during degranulation of mast cells and basophils.
Individuals with which of the following diseases would be expected to have very low antibody titers overall?
SCID
Which of the following mutations would not result in antibiotic resistance?
Silent mutation
How is simple diffusion different from other types of passive transport?
Simple diffusion does not require a permease.
Which of the following characteristics of a catheter should be considered, to help minimize the spread of nosocomial infections?
Single-use
How many codons code for the amino acid arginine?
Six
GM crops have raised issues among communities in which they are produced. Which of the following are concerns raised by the public about genetically engineered crops?
The Bt toxin could negatively affect the taste of the food that is produced from these crops The Bt toxin could result in the death of non-pest species of insects The Bt gene could ultimately make the plants pathogenic to humans
How do axial filaments differ from regular bacterial flagella?
The axial filament is located between the cell membrane and the outer membrane.
Where are the complement proteins found in the body?
The blood serum
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.
What characteristic of the S strain allows it to evade the immune system of the mice?
The cells have a capsule.
What must occur for bacterial conjugation to take place?
The cells must come into contact with each other
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
What is hemolysis?
The destruction of red blood cells.
Why is reduction the term used to describe the gain of an electron?
The electron acceptor's net charge decreases
What is a thermocycler
The machine that controls the heat of the reaction, cycling between the different temperatures of the different steps during PCR
What is a thermocycler?
The machine that controls the heat of the reaction, cycling between the different temperatures of the different steps during PCR
Which is an example of vehicle disease transmission?
The presence of Listeria on undercooked chicken served for dinner.
What is apoptosis?
The process of programmed cell death.
Tegument
The viral protein layer located between the capsid and the envelop in the complex icosahedral viruses
A lytic virus has infected a patient. Which of the following would best describe what is happening inside the patient?
The virus is causing death of the infected cells in the patient.
Explain why algae cannot grow inside the human body to cause diseases?
There is no light inside the human body.
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.
How are the bacteria and the archaea different from all the other cellular microbes?
They have no nucleus.
Which of the following is NOT a characteristic of protozoa?
They are all photosynthetic.
Why are anaerobes killed when exposed to oxygen?
They cannot produce catalase and superoxide dismutase. Because when exposed to oxygen they can produce reactive oxygen species (ROS).
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.
How does a competitive inhibitor slow enzyme catalysis?
They compete with the substrate for the enzyme's active site.
What is the role of opsonins?
They create "handles" that make it easier for the pseudopods of phagocytes to attach to the microbe invader.
What is the fate of activated cytotoxic T-cells?
They proliferate into a clone of cells specific to the same antigen; some of these cells then differentiate into long-lived memory T-cells, while others mature to attack infected cells.
What is the function of the primers in PCR?
They provide a 3' end for the DNA polymerase
A skin test was carried out with three potential allergens. The results (at 15 minutes after exposure) are shown below. What do these results suggest?
This person has been sensitized to peanuts and has IgE bound to mast cells.
What is the purpose of staining?
To increase contrast.
In general, how might recombinant DNA technology be used to prevent a genetic disorder caused by a mutation in a single gene?
To insert a desirable gene, remove an undesirable gene, or replace a defective gene with a functioning gene
Enzymes Needed by DNA
Transcription of viral DNA is preformed by the host cell's RNA polymerase (except poxviruses, which bring their own)
What is unique about transduction compared to normal bacteriophage infection?
Transduction transfers DNA from the chromosome of one cell to another.
What is unique about transduction compared to normal bacteriophage infection?
Transduction transfers DNA from the chromosomes of one cell to another
Which of the following is the current standard test used in the United States to evaluate disinfectants and antiseptics.
Use-dilution test
What is the name of genetic tools that can deliver genes into a cells?
Vectors
Which of the following statements regarding vectors is FALSE?
Vectors are generally over 100,000 base pairs in size
Which of the following statements regarding vectors is FALSE
Vectors are generally over 100,000 base pairs in size.
Which of the following statements regarding vectors is FALSE?
Vectors are generally over 100,000 base pairs in size.
Which of the following is NOT a vector?
Vectors: Transposons, Plasmids, Viruses
Lysogenic Infection
Viral genome becomes incorporated into host cell's DNA and can remain this way for an extended period. This causes a latent infection in which there is no new viruses made and no increase in infection.
Why is it difficult to find good chemotherapeutic agents against viruses?
Viruses depend on the host cell's machinery, so it is hard to find a viral target that would leave the host cell unaffected.
Why is it difficult to find good chemotherapeutic agents against viruses? There is no effective way to deliver the drug to the virus. Viruses are not cells, and therefore not sensitive to such compounds. Viruses infect both bacteria and human cells. Viruses depend on the host cell's machinery, so it is hard to find a viral target that would leave the host cell unaffected.
Viruses depend on the host cell's machinery, so it is hard to find a viral target that would leave the host cell unaffected.
Complex Viruses
Viruses without either helical or icosahedral symmetry
How is osmosis different from simple diffusion?
Water movement is driven by the concentration of solutes rather than its own concentration
What does a vaccine contain?
Weakened or killed pathogen or parts of a pathogen
How is translation terminated?
When a protein called a release factor enters and binds to the A site
Virus / Receptor Infection
When a virus binds to a receptor it facilitates the infection process by enhancing virus entry into host cell
Which of the following is NOT an important consideration when preparing to use a chemical to disinfect a diaper changing table in a public restroom?
Whether or not hand sanitizer is available at the changing table
Wild rodents are the major reservoir of the plague organism, Yersinia pestis, but pandemic plagues were historically associated with crowded, unsanitary urban areas. Why is this the case? Yersinia pestis can be transmitted by fleas from wild rodents to urban rats, which quickly die of the disease. Humans are accidental hosts due to fleas seeking out blood meals after most rats have succumbed to the disease. Wild rodents tended to have high plague mortality rates, but most urban rats survived infection. This allowed the disease to be passed on to nearby humans by the vector. At one time, it was fashionable for city dwellers to keep rats as pets, bringing humans into close contact with these plague hosts. Crowded urban areas have more garbage and filth, allowing plague to spread more easily due to unsanitary conditions.
Yersinia pestis can be transmitted by fleas from wild rodents to urban rats, which quickly die of the disease.
Application uses PCR Y/N? Diagnosing a disease
Yes
Application uses PCR Y/N? Providing enough DNA for cloning into another organism
Yes
Application uses PCR Y/N? sequencing a gene
Yes
During a flood, a community's well water system is contaminated with a pathogenic fungus. If the residents boil their water for 15 minutes prior to consumption, will they be protected?
Yes, Most likely; 100º C, >/= 10 min kills vegetative bacterial cells, fungi, protozoan trophozoites, most viruses
If you used a broken thermocycler that could not heat above 75°C, which of the following problems could you expect?
You would not get any amplification of DNA.
A library of cloned sequences representing the expressed genes of an organism is known as a a. cDNA library. b. DNA fingerprint. c. FISH library. d. gene library. e. microarray.
a
A researcher inserted DNA fragments from an organism into plasmids and introduced the modified plasmids into bacterial cells. Which of the following methods would be the most efficient means of identifying which clones contain a specific gene of interest? 24) ______ A) use a labeled synthetic probe complementary to the gene sequence B) use electrophoresis to identify plasmids containing an insert of the expected size C) sequence the DNA of the plasmids from each isolate D) assay for activity of the gene product E) use a microarray to detect a transcript of the gene
a
Which of the following devices is used for PCR?
a thermocycler
In the 20th century, scientist harnessed the natural metabolic reactions of bacteria to make ________ for the first time in an industrial setting
acetone
In the 20th century, scientists harnessed the natural metabolic reactions of bacteria to make ________ for the first time in an industrial setting.
acetone
Sebum contains ________ which contributes to creating an inhospitable environment on the surface of the body.
acids
Which of the following transport process need ATP?
active transport
During DNA electrophoresis, DNA molecules pass through __________, which separates the molecules according to size.
agarose
Disinfectants known as (alcohols/oxidizers/aldehydes) have the chemical group -CHO, which reacts with and damages both proteins and nucleic acids.
aldehydes
Which of the following is NOT an example of a fungus?
algae
Which of the following is generally NOT considered an ethical issue regarding recombinant DNA technology? the modification of crop plants screening of humans for genes that predispose them to disease unforeseen impact on the environment answering basic research questions the modification of animals to produce pharmaceuticals for humans
answering basic research questions
The restriction enzyme KpnII probably originated __________.
as the second discovered restriction enzymes from Klebsiella pneumoniae bacterium
GAU codes for
aspartic acid
A microbial control agent that kills bacteria is _
bactericidal
A (bacteriostatic/bacteriocidal/minimum) concentration of a drug is one at which microbes survive but are not able to grow and reproduce.
bacteriostatic
A library of cloned sequences representing the expressed genes of an organism is known as a a. cDNA library. b. microarray. c. DNA fingerprint. d. gene library. e. FISH library.
cDNA library
A library of cloned sequences representing the expressed genes of an organism is known as a(n)
cDNA library.
Lactobacillus bulgaricus ferments milk sugars as a step in the production of some cheeses. antibiotics. soy sauces. wines.
cheeses.
Which of the following processes did NOT contribute to the development of genetic engineering?
chemiosmosis
Which type of metabolic diversity contains most pathogens?
chemoheterotroph
The microorganisms that use carbohydrates as sources of carbon and energy are called ________. It is a one-word answer (plural) and spelling matters.
chemoheterotrophs
The process by which a phagocyte moves toward a chemical signal at the site of an infection is called
chemotaxis.
Based on energy source, animals, fungi and most bacteria are ________. It is a one-word answer (plural) and spelling matters.
chemotrophs
Which of the following is characteristic of prokaryotic genomes but NOT eukaryotic genomes?
circular chromosomes
The part of taxonomy that is responsible for the arrangement of organisms into groups or taxa is called ________. It is a one-word answer and spelling matters.
classification
Gram-negative, rod-shaped bacteria that are facultative anaerobes, are non-spore formers, and ferment lactose to acid and gas are __________. fecal bacteria pathogens coliforms indicator organisms
coliforms
Obligate anaerobes are likely to be found in the __________. mouth urogenital tract nasal cavity colon
colon
A collection of bacterial clones each of which contains a portion of the gene sequences of an organism is known as a microbiome of that organism's genome.
false
Gene therapy for human genetic diseases has not been successful yet.
false
Which of the following is NOT a direct mode of action of antimicrobial drugs?
inhibition of flagella formation
An important characteristic of antibacterial drugs is their selective toxicity. If antibacterial drugs were not selectively toxic, then they would kill or interfere with the hosts' cells as well as bacterial cells. Examining cellular differences between bacterial (prokaryotic) cells and host (eukaryotic) cells suggests strategies to achieve selective toxicity. We can capitalize on these differences and take advantage of them in the design of antibacterial drugs Identify antibacterial strategies that would likely be selectively toxic for bacteria.
interfering with translation at 70s ribosomes inhibition of peptidoglycan synthesis inhibition of fimbriae synthesis
The disinfectant that can kill mycobacteria but not endospores are the ________.
intermediate level disinfectant
A glycoprotein
is a type of peripheral protein above that can be used as a receptor or in enzymatic functions.
Okazaki fragments are formed because DNA replication __________.
is discontinuous on the lagging strand
A drug with high therapeutic index is ________.
less toxic to the patient
A set of clones representing the entire genome of an organism is known as a gene (recombinant/map/library).
library
A set of clones representing the entire genome of an organism is known as a gene ________.
library
What is the enzyme that is used to join the DNA together? It is a one-word answer (singular) and spelling matters.
ligase
The presence of microbes in the bladder is __________. likely to lead to a UTI used to prime the immune response more likely to occur in men than women normal
likely to lead to a UTI
Helical Viruses
long rigid/flexible rods consisting of capsomeres arranged helically around NA (form hollow capsid tube) influnza in a Helical virus.
They are the smallest leukocytes and have nuclei that nearly fill the cell. It is a one-word answer (plural) and spelling matters.
lymphocyte
Which of the following is NOT a goal of recombinant DNA technology?
making it possible to clone humans
After a successful endospore staining, the endospores are colored by what stain? And the vegetative cells are colored by what stain?
malachite green ; safranin
After tuberculosis, malaria causes more annual deaths worldwide than any other single disease. Recent research has attempted to control the spread of malaria by genetically-modifying a bacterium (Pantoea agglomerans) commonly found in the guts of mosquitos to produce a toxin that kills the malaria parasite Plasmodium falciparum. If this project is effective it could significantly decrease the incidence of malaria because__________. malaria is a vectorborne disease. the mosquitoes will die. Pantoea agglomerans would be killed. malaria is a person-to-person disease.
malaria is a vectorborne disease.
Vectors usually contain genetic (markers/sequences/probes) such as antibiotic genes or fluorescent tags.
markers
Type I hypersensitivity involves degranulation of
mast cells
DNA microarrays can be used to
monitor gene expression
Which of the following serve as portals of entry of pathogens?
mouth placenta mucus membranes in the eyes
Taxis is
movement towards or away from a stimulus.
________ are chemical and physical agents used to create changes in the genome of the microorganisms to effect desired changes in the phenotype of the microorganisms. It is a one-word answer (plural) and spelling matters
mutagens
Chemical and physical agents can cause changes in nucleotide squences in DNA. Such agents are polymerase chain reactions. reverse transcriptase. mutagens. restriction enzymes.
mutagens.
What is the waxy fatty acid present in AF+ that prevents uptake of dyes? It is a two word answer and spelling matters.
mycolic acid
Which of the following chemical substances contributes to the unique characteristics of acid-fast bacteria?
mycolic acid
A patient who has been hospitalized with uncontrolled muscle spasms has probably been infected with bacteria that secrete a(n)
neurotoxin.
Stethoscope is what type of medical instrument based on risk for transmitting infectious agents?
non-critical instrument
Which of the following types of mutations always creates a stop codon where one did not exist before?
nonsense mutation
Fermented foods such as sauerkraut or pickles are kept from spoiling by the effects of which of the following?
pH
What is the pH of our skin? Support your answer.
pH is low because the secretion of the sebaceous gland makes the skin acidic.
The process of heating milk or fruit juice to levels that kill any pathogenic microbes present is known as (pasteurization/sanitization/lyophilization).
pasteurization
The ability to cause disease is __________. virulence pathogenicity colonization infection
pathogenicity
Clavulanic acid could be used to protect which of the following antibiotics in a drug formulation?
penicillin
What mainly composed bacterial cell walls? It is a one-word answer and spelling matters.
peptidoglycan
Which of the following is a sterilizing agent?
peracetic acid
Antimicrobial agents that damage the viral envelope __________.
prevent attachment of the virus to its target cell
The natural role of restriction enzymes in bacteria is to
protect the cell from invading phages
The natural role of restriction enzymes in bacteria is to
protect the cell from invading phages.
Which of the following recombinant tools is NOT used in DNA fingerprinting? a. reverse transcription b. neither PCR nor gel electrophoresis is used. c. restriction enzyme digestion d. gel electrophoresis e. PCR
reverse transcription
What enzyme is used to copy nucleotide sequences to make cDNA? It is a two-word answer (singular) and spelling matters.
reverse transcriptase
Which of the following is necessary to produce an "expression" library representing the active genes of an organism? a. synthetic nucleic acids b. mutagens c. a gene gun d. nucleic acid probes e. reverse transcriptase
reverse transcriptase
Synthesis of cDNA requires the use of
reverse transcriptase.
Which of the following virulence factors would be found in Staphylococcus aureus? Hyaluronidase Collagenase Streptokinase Staphylokinase
staphylokinase
Point mutations are those that alter a single base pair or base location, and include substitutions and frameshift mutations. They can range in severity from no phenotypic change to complete loss of function. Rank the following point mutations in order of least damaging to most damaging if they occur in the middle of the coding sequence of a polypeptide.
silent missense Frameshift Nonsense
Which of the following mutations would not result in antibiotic resistance? Missense mutation Nonsense mutation Silent mutation Frameshift insertion Frameshift deletion
silent mutation
What type of culture medium is nutrient agar based on form and composition? Components of the medium are given below. Nutrient agar g/L Peptone - 3 Beef extract - 5 Agar - 15
solid and complex
Termites are capable of digesting cellulose and hemicellulose due to the presence of __________. enzymes that digest these compounds symbiotic bacteria in their gut endosymbiotic bacteria none of the listed responses
symbiotic bacteria in their gut
purple oval long chain bacterial cell image
streptobacillus
What kind of chemical does Saccharomyces cerevisiae ferment to produce alcohol? proteins fats amino acids sugars
sugars
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.
The absence of ________ leaves obligate anaerobes susceptible to killing by oxygen.
superoxide dismutase
What is translation?
synthesis of proteins from mRNA
CC: Keesha's treatment uses polymerase chain reaction (PCR). PCR is used in recombinant DNA technology to ________________.
synthesize millions of copies of a DNA molecule
The enzyme reverse transcriptase
synthesizes DNA from an RNA template
Which of the following groups of drugs can become incorporated into the bones and teeth of a fetus?
tetracyclines
Tumbles occur when
the flagella rotate clockwise and the flagellum separate
Peritrichous bacteria make a run when
the flagella turn counterclockwise and become bundled.
A clinical sample labeled as "sputum" was collected from
the lungs.
Four different fluorescent dyes are used in automated DNA sequencing because __________.
there are four different bases in DNA
Four different fluorescent dyes are used in automated DNA sequencing because
there are four different nucleotides in DNA
Which of the following devices is used for PCR?
thermocycler
Which of the following processes is involved in the "central dogma" of genetics?
transcription and translation
In ggeneralized transduction, the donor DNA is carried by the ________.
transducing phage
The process of acquiring antibiotic resistance by means of bacteriophage activity is called transduction. R-plasmid acquisition. point mutation. transformation.
transduction
The process of acquiring antibiotic resistance by means of bacteriophage activity is called
transduction.
Which RNA carries amino acids to the ribosome?
transfer RNA
When the recombinant plasmid is introduced to E. coli, what type of gene transfer is it?
transformation
Which of the following will most likely contribute to the spread of a genetic mutation among bacterial species?
transformation
A patient is infected with a bacterium that produces the enzyme beta-lactamase; this enzyme
inactivates penicillins, carbapenems, and cephalosporins.
The typical progression of symptoms for an acute infection would be __________. infection-acute period-incubation-decline period-convalescence incubation-acute period-infection-decline period-convalescence incubation-infection-acute period-decline period-convalescence infection-incubation-acute period-decline period-convalescence
infection-incubation-acute period-decline period-convalescence
As a bacterium approaches a food source, one would expect
runs to become more frequent.
If eight spherical cells are grouped and forms a cube, the arrangement is called ________. It is a one word answer and spelling matters.
sarcina
What is the primary benefit of vaccination?
An immune response will occur quicker upon future exposure to the pathogen.
Why might a transfusion of Rh+ blood cells into an Rh- individual be dangerous?
An individual with Rh- type blood will produce antibodies against the Rh+ blood cells.
Why is DNA replication essential for a cell?
An organism must copy its DNA to pass genetic information to its offspring.
(Q) What Is Happening during Stationary Phase? After a period of rapid growth (log phase), bacterial growth rates will slow and enter the stationary phase. The number of viable cells no longer increases, but instead stays constant. In this activity you will indicate the statements that correctly describe what is happening during stationary phase. Select each statement that accurately describes what is happening to bacterial cultures during stationary phase. (1) Harmful waste products may be accumulating. (2) The number of cells that are dying is balanced by the number of new cells that are being formed. (3) Cells are not increasing in number because they have not yet adjusted to the nutrient availability in the new media. (4) The cells are likely running out of nutrients. (5) The cells are dead; therefore, the number is staying constant.
Answer: (1) Harmful waste products may be accumulating. (2) The number of cells that are dying is balanced by the number of new cells that are being formed. (4) The cells are likely running out of nutrients. Extra: During the stationary phase, the number of viable cells does not increase and remains constant, or stationary. This phase begins as the nutrient supply is depleted and/or waste products begin to accumulate at a toxic level. During log phase, bacteria are actively growing and metabolizing. If the bacteria are being cultured for industrial purposes, such as producing amino acids or some other desirable product, they are generally most productive during log phase. For this reason, it is desirable to extend or prolong log phase.
(Q) The Lake of the Ozarks is a human-made lake, so it collects runoff from coal strip-mining, fertilizers, resort wastewaters, and septic drainages. The average lake temperature is between 10∘C and 21∘C Consider the physical requirements for growth and multiplication that would allow fecal coliforms to "blossom" in the Lake of the Ozarks. Which of the following would accurately describe these organisms? (1) Hyperthermophiles (2) Facultative halophiles (3) Extremophiles (4) Psychrophiles (5) Mesophiles
Answer: (2) Facultative halophiles (4) Psychrophiles (5) Mesophiles Extra: The bacterial growth process depends on the microorganism's ability to adapt to environmental conditions. Being able to grow to larger numbers increases the chances for survival and spread to new hosts. Requirements for growth have led us to develop descriptive terms for the organisms that refer to temperature range [Chapter 6, section 6-1], pH range [Chapter 6, section 6-2], and pressure range [Chapter 6, section 6-3]. More Extra: Growth of the fecal coliform bacteria in the lake involves more than just simple physical conditions. Nutrients must also be available to build and support the new cells. As such, we also must consider the chemical requirements associated with this outbreak.
(Q) In addition to physical requirements, bacterial growth and multiplication also entails chemical requirements. Which of the following statements would accurately describe chemical requirements and conditions associated with growth in the Lake of the Ozarks environment? (1) The lake environment will support only the growth of obligate anaerobes. (2) The lake environment will support the growth of facultative anaerobes. (3) Fecal coliforms will need to acquire trace elements for growth in the lake environment. (4) Fecal coliforms will likely contain enzymes to counteract toxic oxygen forms. (5) Fecal coliforms will not need organic growth factors to grow in the lake environment.
Answer: (2) The lake environment will support the growth of facultative anaerobes. (3) Fecal coliforms will need to acquire trace elements for growth in the lake environment. (4) Fecal coliforms will likely contain enzymes to counteract toxic oxygen forms. Extra: With chemical and physical requirements met, bacteria are able to replicate in their environment and potentially increase numbers enough to find or invade a new host. More Extra: Recall that fecal coliforms are generally found in the intestines of warm-blooded animals. As such, they are adapted to be a part of a specific community of gut flora. The coliform organisms in the Lake of the Ozarks now find themselves in a completely different environment and bacterial community.
(Q) Which of the following would you expect to be a function of MacConkey agar? Mark all that apply. (1) allow for the growth of all organisms in a sample regardless of nutritional requirements (2) allow for the growth of all organisms in a sample that require only the most common nutrients (3) inhibit the growth of certain bacteria (4) change the color of some organisms based on their metabolic characteristics
Answer: (3) inhibit the growth of certain bacteria (4) change the color of some organisms based on their metabolic characteristics
What is the role of normal microbiota in preventing disease?
Normal microbiota compete with pathogens for resources, limiting their growth.
What cellular macromolecule is the fertility factor compromised of?
Nucleic Acid
What cellular macromolecule is the fertility factor comprised of?
Nucleic acid
A bacterial culture that grows only near the surface of a thioglycolate broth is an example of what type of organism?
Obligate aerobes
Un-Coating
Once inside cell, virus must uncoat its capsid. This takes place in either: -The Plasma membrane -The cytoplasm -At nuclear membrane
The process of filtration is a(n)
sterilizing method
Which of the following phenomena produces magnification?
the refraction of radiation as it passes through a lens
Which of the following statements concerning osmosis is FALSE?
During osmosis, water crosses to the side of the membrane with a lower solute concentration
When does MHC-II loading occur?
During the fusion of vesicles containing MHC-II proteins with vesicles containing digested pathogens
CONJUGATION
-donor and recipient cells must be of an opposite mating type -requires direct contact between bacterial cells, which is typically mediated by a sex pilus
SPECIALIZED TRANSDUCTION
-during phage infection, particular bacterial genes are transferred to the recipient
Reverse Transcriptase (HIV has this)
-is a DNA polymerase enzyme that transcribes single-stranded RNA into single-stranded DNA. -It also helps in the formation of a double helix DNA once the RNA has been reverse transcribed into a single strand cDNA. -Normal transcription involves the synthesis of RNA from DNA; hence, reverse transcription is the reverse of this.
REPLICATION
-picture with 3 cells -DNA -> 2 DNA (copying one DNA molecule to make two identical DNA molecules)
RECOMBINATION
-picture with donor and recipient cell -transformation -transduction -conjugation
Diphtheria toxin kills eukaryotic cells by affecting translation. More specifically, the toxin prevents movement of tRNAs from the A site to the P site of the ribosome. Predict what the result(s) of this inhibition would be.
-protein synthesis will be interrupted because the peptide chain is inhibited from growing -New tRNAs will not be able to enter the ribosome.
Which of the following situations is NOT a way in which a baby acquires normal microbiota?
Microbes cross the placenta during pregnancy.
Which of the following procedures would be used to introduce DNA into a single mouse cell?
Microinjection
Not all changes in amino acid sequence are deleterious, some may even be beneficial. Which of the following point mutations is most likely to alter a protein product without destroying its function?
Missense
Which of the following types of bacterial cells would have only a single flagellum?
Monotrichous
Which of the following scientists provided evidence in favor of the concept of spontaneous generation?
Needham
Whose experiments supported the existence of a "life force" that causes inanimate matter to spontaneously come to life?
Needham
Acidic dyes are commonly used for ________ stains.
Negative
Which type of staining is suitable to color bacterial capsules?
Negative staining
Meningitis and gonorrhea are caused by
Neisseria species.
The enzyme reverse transcriptase
Converts RNA into DNA
Which of the following describes rDNA technology?
Deliberate modification of the genome of an organism for practical purposes.
What provides the energy for DNA polymerization in a PCR reaction?
Deoxyribonucleoside triphosphates
Membrane transport proteins are required for which mode(s) of antibiotic resistance?
Efflux pumps, beta-lactamases, and modification of porins all utilize membrane transport proteins.
Membrane transport proteins are required for which mode(s) of antibiotic resistance? Efflux pumps Modification of a porins Modification of a metabolic enzyme Beta-lactamases Efflux pumps, beta-lactamases, and modification of porins all utilize membrane transport proteins.
Efflux pumps, beta-lactamases, and modification of porins all utilize membrane transport proteins.
Viruses Contain?
Either RNA or DNA
Non-enveloped animal viruses penetrate host cell by...?
Endocytosis
In which direction does the replication fork move?
It moves ahead of the newly synthesized DNA.
What is a hallmark of passive transport across cell membranes?
It occurs along an electrochemical gradient, and may involve the use of transport proteins.
Which of the following statements regarding active transport is false?
It powers the diffusion of water across the cell membrane.
What are leukocidins?
Molecules that are capable of destroying phagocytes
What are leukocidins? Molecules that can degrade IgA Molecules that destroy the complement proteins Molecules that are capable of destroying phagocytes
Molecules that are capable of destroying phagocytes
Match the Gram stain with their functions.
Mordant A. forms CV-I complex, intensify color Crystal violet B. primary stain Safranin C. secondary stain Alcohol D. decolorizer
A researcher mistakenly uses a heat-sensitive version of DNA polymerase in a PCR. Which of the following will occur?
The PCR will stop after one cycle
A researcher mistakenly uses a heat-sensitive version of DNA polymerase in a PCR. Which of the following will occur?
The PCR will stop after one cycle.
First line defenses have what aspect in common with each other?
They are physical barriers against invading pathogens.
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.
A (capsule/slime layer/matrix) is a type of glycocalyx that is firmly attached to the cell.
capsule
Some bacteria have an outer layer called a ________ which allows them to adhere to surfaces and contributes to their ability to cause disease.
capsule
A person who tests positive for the human immunodeficiency virus but shows no symptoms of AIDS would be termed a __________. vector carrier reservoir vehicle
carrier
TLRs are located in what part of the phagocytes?
cell membranes
How did the multi-drug-resistant strains of Mycobacterium tuberculosis, like those in the prison, arise?
conjugation and exchange of resistance factors located on plasmids
Transgenic organisms
contain genes from other organisms
Transgenic organisms
contain genes from other organisms.
Transgenic organisms have genomes that have been sequenced completely. contain cells from other organisms. contain genes from other organisms. contain genetically engineered microbes. are the same as clones.
contain genes from other organisms.
A transducing phage
contains fragments of the host chromosome instead of the viral genome
A transducing phage
contains fragments of the host chromosome instead of the viral genome.
What is the role of plasma cells in humoral immunity?
Plasma cells produce antibodies.
Many bacteria have additional small molecules of DNA in addition to their main genome. What are these small molecules called?
Plasmids
What are plasmids?
Plasmids are small, usually circular, molecules of DNA often found in prokaryotes that replicate independently.
Which of the following antibiotics are properly matched with their target of action? macrolide-30S ribosomal subunit Platensimycin-lipid biosynthesis aminoglycoside-50S ribosomal subunit tetracycline-50S ribosomal subunit
Platensimycin-lipid biosynthesis
Match the examples to their method (terms) of microbial control
Plates and silverwares are washed in boiling water in campus dining hall D. sanitization You wash your hands with plain soap and water. E. degerming Heat is used to kill potential pathogens in milk. C. pasteurization An autoclave is used to prepare nutrient agar. B. sterilization You apply hand sanitizer (alcohol) in your hands. A. antisepsis
Why are smokers more likely to have infections with respiratory pathogens?
Poisons and tars in tobacco smoke damage ciliated columnar cells.
If a microbe were capable of preventing a phagosome from fusing with a lysosome, which of the following would occur?
The microbe would survive inside the phagocyte.
When might Rh antigens from the fetus be introduced into the mother's blood stream?
The mother may be exposed during labor or delivery.
What is the cause of hemolytic disease of the newborn?
The mother produces anti-Rh antibodies which cross the placenta and react with baby's Rh antigens.
Mucous membranes are quite thin and fragile. How can such delicate tissue provide defense against microbial invaders?
The mucus physically traps microbes, contains a variety of antimicrobial chemicals, and is shed constantly, along with the outermost layer of cells.
Louis Pasteur's experiments disproving spontaneous generation were different from John Needham's in which important way?
The necks of the flasks Pasteur used were bent into an S-shape and left open to the air.
Protoplasts are valuable in techniques that are used to insert DNA in cells because __________.
They have no cell wall to interfere with the entry of DNA into the cell
Which of the following amino acids is coded by only one codon?
Trp
Which of the following statements is TRUE of eosinophils?
They secrete toxins onto the surface of helminth parasites
A single basic dye is used in simple stains.
True
Amino acid and vitamin supplements are prepared from extracts of microbial cultures. . True False
True
Koch's postulates can be used to determine the causes of infectious diseases.
True
Why is the tryptophan operon turned off in the presence of tryptophan?
Tryptophan binds to and activates the repressor proteins; the repressor proteins, in turn, bind to the operator, preventing transcription.
Which of the following microorganisms actually grows inside the macrophage? Tuberculosis bacterium Shigella Leishmania Streptococcus pneumoniae Legionella
Tubercolosis bacterium
How can surgeons help to limit nosocomial infections?
They should perform surgeries and invasive procedures only when absolutely necessary.
Which of the following statements are true about antigens?
They stimulate the production of antibodies. They possess epitopes. They can be endogenous or exogenous.
A company uses an industrial process that produces sulfurous waste products. The owners of the company want to use microbes to recycle the sulfur. You suggest they might consider using Rhizobium. Thiobacillus. autotrophs. Escherichia coli.
Thiobacillus
Which of the following microorganisms actually grows inside the macrophage?
Tuberculosis bacterium
Starting with three cells, how many cells would result from three rounds of replication?
Twenty-four
What are the products of semiconservative replication for a double-stranded DNA molecule?
Two double-stranded DNA molecules, each consisting of one parental strand and one daughter strand.
What results when a single bacterium reproduces?
Two genetically identical daughter cells
Drag the correct labels onto the nucleotides in the RNA transcript. Not all labels will be used.
UCGA
Which of the following radiations can damage the DNA by formation of dimers?
UV light
Match the microbial control methods on the left with their uses.
UV radiation B. destroys microorganisms in the air filtration of fluid A. sterilizes heat sensitive medications ionizing radiation C. sterilizes heat sensitive medical equipment incineration D. sterilizes wire loops
Milk that can be stored for months at room temperature has been treated by which of the following methods?
Ultrahigh-temperature sterilization kills all forms of living microbes: UHT-sterilized milk can be kept at room temperature indefinitely without spoilage, although flavor changes may occur
Which of the following shows the moist heat methods in order of the temperature used (highest to lowest)?
Ultrahigh>Autoclave>Boiling>Batch Pasteurization
Quiz 4
Unable to get into gradebook
A researcher inserted DNA fragments from an organism into plasmids and introduced the modified plasmids into bacterial cells. Which of the following methods would be the most efficient means of identifying which clones contain a specific gene of interest? a. Use a microarray to detect a transcript of the gene. b. Sequence the DNA of the plasmids from each isolate. c. Use electrophoresis to identify plasmids containing an insert of the expected size. d. Use a labeled synthetic probe complementary to the gene sequence. e. Assay for activity of the gene product.
Use a labeled synthetic probe complementary to the gene sequence
A scientist wants to add DNA to a particular genome using a vector. One vector she might use is reverse transcription injection. a plasmid. a mutagen.
a plasmid.
When the wasps stung Sally, the injection of venom initiated a type I hypersensitivity reaction called anaphylaxis. Which of the following best describes a hypersensitivity reaction?
a reaction that occurs in a sensitized individual resulting in tissue damage rather than immunity
A scientist wants to insert a gene into several different organisms at several different sites. The best type of restriction enzymes would be ones that produce vectors. sticky ends. blunt ends. DNA probes.
blunt ends. (Blunt-ended DNA fragments can be joined even if they are produced by different restriction enzymes.)
Which of the following is a microbial product used to reduce crop damage? saxitoxin Bt toxin ice-minus both Bt toxin and ice-minus both Bt toxin and saxitoxin
both Bt toxin and ice-minus
Which of the following is essential in PCR?
both DNA primers and DNA polymerase
Which of the following is essential in PCR? a. both DNA primers and DNA polymerase b. DNA polymerase c. reverse transcriptase d. DNA primers e. antisense RNAs
both DNA primers and DNA polymerase
When mast cells degranulate and release histamine, which of the following events may occur?
both bronchial spasms and increased mucus production
The DNA double helix can be separated into single strands using
both heat and NaOH.
Which of the following may be a component of bacterial cell walls?
both lipoteichoic and mycolic acids
The technique of ________ is a means of determining the function of a gene by the phenotype resulting from its absence.
gene knockout
The removal of a gene from an organism's genome to study its function is a technique known as
gene knockout.
Competent cells are cells that
can take up DNA from their surrounding environment and integrate it into their own chromosomes by recombination.
What part of the viral particle encloses the genetic material? It is a one-word answer and spelling matters.
capsid
If a scientist wanted to view the location of a particular species of bacterium within a biofilm, which technique could the scientist use?
fluorescent in situ hybridization (FISH)
Illness that results from ingestion of pathogen-contaminated food is __________. foodborne disease food infection food poisoning food intoxication
food infection
DNA fingerprinting can be used
for forensics and detection of unculturable organisms.
DNA fingerprinting can be used for forensics and detection of unculturable organisms. b. to detect unculturable organisms. c. in forensic investigations. d. to generate cDNA clones. e. to generate cDNA clones and libraries.
for forensics and detection of unculturable organisms.
An antigen is a
foreign substance that stimulates immunity.
A base insertion or deletion in the translated region of the gene may lead to
frameshift mutation
A new chemotherapeutic agent is developed that alters the structure of all thymines in DNA. These thymines are then misread during the production of mRNA. Which of the following could NOT result from this type of mutation?
frameshift mutation
Insertions and deletions usually lead to which of the following types of mutations?
frameshift mutations
Which of the following pairs of industrial microbial products and their uses is MISMATCHED? citric acid; antioxidant in food gluconic acid; release of cellulose from flax to make linen phenylalanine; the sweetener aspartame indigo; cloth dye streptokinase; dissolving blood clots
gluconic acid; release of cellulose from flax to make linen
Which of the following is part of the endomembrane system?
golgi apparatus
Attenuated virus vaccines can be produced by which of the following processes?
growth in tissue culture cells for many generations
Application of ________ in acid-fast staining facilitate the uptake of the primary stain by AF+ bacteria. It is a one-word answer and spelling matters.
mordant heat
In the first reported epidemiological study in 1854, John Snow attempted to discover the source of a London cholera epidemic by going house-to-house and recording deaths. When he mapped the results, he was able to identify the Broad Street water pump as the likely source of contaminated water. The data collected in this study was__________. morbidity. incidence. prevalence. mortality.
mortality
What microorganisms are killed by low level disinfectants/ and antiseptics?
most Gram positive and Gram-negative bacteria large non-enveloped viruses trophozoites enveloped viruses
In gel electrophoresis, DNA molecules move toward the __________ electrode because they have an overall __________ charge.
positive, negative
In gel electrophoresis, DNA molecules move toward the ________ electrode(s) because they have an overall ________ charge. a. positive; negative b. negative; positive c. positive; positive d. negative and positive; neutral e. negative; negative
positive; negative
A mutant bacterium has a net positive charge on its surface. If the bacterium is stained with Congo red (an acidic stain), what would be the color of the cells? Hint! Principle of staining.
red
Of the following events in a type I hypersensitivity reaction, which one would be expected to occur LAST?
release of leukotrienes by eosinophils
Washing your hands with plain soap can control the spread of COVID-19 because the process ________.
removes microorganisms mechanically
Which drug for the treatment of tuberculosis inhibits RNA production and colors body secretions red-orange?
rifampin
The lowest number of pathogens or pathogen produced products that can be detected is a measure of __________. sensitivity specificity discrimination selectivity
sensitivity
Which of the following is not an example of direct contact transmission of disease?
sharing a drinking glass
Drugs with (longer / shorter) half-life are given to patients more frequently?
shorter
The health of the patient
should be the primary concern of the healthcare worker.
According to the animation, for approximately how many days is IgG present in the serum?
ten days
Which of the following items is NOT a part of the name of a restriction enzyme?
the Gram reaction of the source bacterium
Which of the following items is NOT a part of the name of a restriction enzyme? a. the strain of the source bacterium b. the genus of the source bacterium c. Roman numerals to indicate its order of discovery d. the Gram reaction of the source bacterium e. the specific epithet of the source bacterium
the Gram reaction of the source bacterium
Which of the following is the preferred method of determining the efficacy of an antimicrobial chemical in the European Union?
the Kelsey-Sykes capacity test
What is microbial antagonism?
the ability of the normal flora to outcompete and outgrow pathogens
A strain of Neisseria gonorrhea has a mutation which has caused it to lose the ability to produce fimbriae and become less virulent as a consequence. What function has this pathogen lost?
the ability to adhere to cells of the body
A microbiologist is using heat to drive the stain carbolfuchsin into a smear. Which of the following staining procedures is being used?
the acid-fast stain
Both the innate and adaptive defenses of the immune system work to prevent
the penetration and colonization by pathogens, and the diseases they cause.
Which of the following is the best definition of "microbial antagonism"?
the presence of normal microbiota that protect the body by competing with pathogens in a variety of ways to prevent pathogens from invading the body
When the cell is not in the presence of lactose,
the repressor proteins bind to the operator.
A patient is sickened after being infected with Escherichia coli (E. coli) from consuming contaminated lettuce; this is a type of _______________ disease transmisson.
vehicle
Of the arthropod-borne diseases, there is a vaccine to prevent __________. West Nile fever yellow fever Lyme disease dengue fever
yellow fever
Infection and disease are NOT the same thing because __________.
disease does not necessarily result from an infection
Streptokinase is useful for which of the following? producing antibiotics cheese production dissolving blood clots insecticide biosensors
dissolving blood clots
In which direction does DNA polymerase synthesize the new DNA strand?
5' to 3'
What enzyme is used to make specific cuts in DNA molecules?
Restriction enzymes
________ are used for cutting DNA molecules into fragments.
Restriction enzymes
__________ are used for cutting DNA molecules into fragments.
Restriction enzymes
An example of a mechanical vector is:
a housefly at a picnic.
RNA polymerase is guided by the
template strand of DNA
RNA polymerase is guided by the
template strand of DNA.
TRANSCRIPTION
-RNA polymerase -DNA -ribonucleotides -promoter
Chapter 8
Homework
What is the temperature used for the extension step?
72 °
(Q) T or F:
Answer: False
Which of the following statements about fungi is FALSE?
Fungi are photosynthetic.
When is the repressor protein transcribed?
It is always transcribed
Which DNA strand is synthesized continuously?
Leading strand
Synthesis of cDNA requires the use of
Reverse Transcriptase
Which of the following are prokaryotes?
archaea
R-plasmids are most likely acquired via
bacterial conjugation.
Which of the following can be used to disinfect air?
both HEPA filters and ultraviolet light
GENERALIZED TRANSDUCTION
-a phage infects the bacterial cell, thereby transferring bacterial, plasmid, and/or viral DNA to the recipient
Distinguishing Features of Gene Transfer Mechanisms in Bacteria: TRANSDUCTION
-a virus that infects bacteria is a key component in this transfer mechanism
Ways for Viruses to spread
-decoy virions -cell to cell -syncytia
NEITHER TRANSCRIPTION NOR TRANSLATION
-deoxyribonucleotides -DNA polymerases -
GENE EXPRESSION
-DNA -> mRNA -> protein -Transcription -Translation -Picture with one cell
Select the statements that accurately describe DNA replication.
-DNA replication can copy plasmids, which can be transferred among bacterial cells of the same generation. - DNA replication provides an exact copy of -DNA for daughter cells (next generation). - DNA replication occurs prior to mitosis and prior to binary fission. - DNA helicase separates the DNA strands, creating a replication fork. - DNA replication is semiconservative. -Topoisomerase and DNA gyrase remove supercoiling ahead of the replication fork. -The major replication enzyme is DNA polymerase.
Which of the following situations is an example of biogeochemical cycling? Select all that apply. Photoautotrophs incorporate carbon dioxide into organic matter using energy from sunlight. Some microbes decompose proteins from dead cells and waste products to their amino acid subunits, which are ultimately converted into ammonia. Bacteria were added to the Gulf of Mexico to degrade oil that was spilled after a deep-water drilling accident. Plants and bacteria incorporate sulfates to become part of sulfur-containing amino acids for humans and other animals.
-Photoautotrophs incorporate carbon dioxide into organic matter using energy from sunlight -Some microbes decompose proteins from dead cells and waste products to their amino acid subunits, which are ultimately converted into ammonia. -Plants and bacteria incorporate sulfates to become part of sulfur-containing amino acids for humans and other animals.
TRANSLATION
-Ribosome -tRNA -codon and anticodon pairing -amino acids
Which of the following situations is an example of a symbiotic relationship? Haemophilus influenzae growing in the respiratory tract Staphylococcus epidermidis growing on the skin E. coli growing in the large intestine of humans fungi growing on the root hairs of plants
-Staphylococcus epidermidis growing on the skin -E. coli growing in the large intestine of humans -fungi growing on the root hairs of plants
GM crops have raised issues among communities in which they are produced. Which of the following are concerns raised by the public about genetically engineered crops? Genetically engineered crops could harm the economy. The Bt toxin could result in the death of non-pest species of insects. The Bt toxin could negatively affect the taste of the food that is produced from these crops. The Bt gene could ultimately make the plants pathogenic to humans.
-The Bt toxin could result in the death of non-pest species of insects. -The Bt gene could ultimately make the plants pathogenic to humans. -The Bt toxin could negatively affect the taste of the food that is produced from these crops.
After their field trips to the cheese factory and the winery, Alexis and her classmates are asked to discuss what they have learned about the microorganisms in these processes. They are also asked to do a group presentation on a beneficial aspect of microbes in an area other than food microbiology. Which of the following could Alexis's group use as the topic for their group project? Select all that apply. Microorganisms, primarily bacteria and fungi, return carbon dioxide to the atmosphere when they decompose organic wastes and dead plants and animals. The bacterium Escherichia coli synthesizes vitamin K and some B vitamins in the large intestine of humans. The eutrophication of bodies of water, such as lakes and rivers, due to the addition of nitrates and phosphates results in increased growth of algae and phytoplankton. Bacteria can be used to remove toxins from underground wells, chemical spills, toxic waste sites, and oil spills, such as the massive oil spill in the Gulf of Mexico in 2010.
-The bacterium Escherichia coli synthesizes vitamin K and some B vitamins in the large intestine of humans. -Microorganisms, primarily bacteria and fungi, return carbon dioxide to the atmosphere when they decompose organic wastes and dead plants and animals. -Bacteria can be used to remove toxins from underground wells, chemical spills, toxic waste sites, and oil spills, such as the massive oil spill in the Gulf of Mexico in 2010.
Distinguishing Features of Gene Transfer Mechanisms in Bacteria: CONJUGATION
-a chemical that blocked the formation of a pilus would block this genetic transfer mechanism -this mechanism requires cell-to-cell contact -this mechanism is initiated by cells with F plasmids
Distinguishing Features of Gene Transfer Mechanisms in Bacteria: TRANSFORMATION
-this mechanism was first explored by Griffith as he studied smooth and rough strains of Streptococcus pneumoniae -This mechanism may result in the transfer of genes that encode antibiotic resistance -Extracellular DNAases would block this transfer mechanism -This mechanism of genetic transfer always involves a one-way transfer from a donor cell to a recipient cell
An Rh- mother has an Rh- baby. What is the risk of her next baby developing hemolytic disease of the newborn?
0% chance
How many endospore/s will be formed from one vegetative cell? Your answer must be numeric only such as 2.
1
Refer to a result of an E-test below. Determine MIC. Your answer must be numeral only such as 2.
1
Typically, how many chromosome/s is/are there in bacteria? Your answer must be numeric only such as 2
1
Which of the following are examples of symptoms of a disease? 1) pain 2) fever 3) itching 4) high blood pressure 5) numbness
1, 3 & 5 only
The United States leads the world in the making of cheese, producing millions of tons each year. What is the correct sequence of events in the production of cheese? Arrange in chronological order the following steps in cheese production. -the curd must be separated from the whey. - lactic acid producing bacteria provide the characteristic flavors and aromas of fermented dairy products - the cheese is allowed to age. -An enzyme is added to the milk that causes clumping and the formation of curd. - the solid portions of the cheese is cut into pieces, drained completely, and compressed for the ripening process.
1. An enzyme is added to the milk that causes clumping and the formation of curd. 2. lactic acid producing bacteria provide the characteristic flavors and aromas of fermented dairy products 3. the curd must be separated from the whey. 4. the solid portions of the cheese is cut into pieces, drained completely, and compressed for the ripening process. 5. the cheese is allowed to age.
1. Food poisoning is usually accompanied by signs like diarrhea, fever, and fatigue. These are all Symptoms that either toxins or Microorganisms may have been ingested. 2. In a Common source epidemic, a single food source is responsible for many individuals getting sick. 3. There are over 250 foodborne illnesses that have been characterized, Microorganisms like Salmonella enterica, E. coli, and Toxoplasma gondii can all cause disease. 4. A Food infection is caused by the consumption of living Microorganisms. 5. When toxins are consumed instead of live microorganisms, this is considered Food intoxication.
1. Food poisoning is usually accompanied by signs like diarrhea, fever, and fatigue. These are all Symptoms that either toxins or Microorganisms may have been ingested. 2. In a Common source epidemic, a single food source is responsible for many individuals getting sick. 3. There are over 250 foodborne illnesses that have been characterized, Microorganisms like Salmonella enterica, E. coli, and Toxoplasma gondii can all cause disease. 4. A Food infection is caused by the consumption of living Microorganisms. 5. When toxins are consumed instead of live microorganisms, this is considered Food intoxication.
1.______ : Organisms that thrive in salt concentrations of more than 25%. 2.______ : Organisms that thrive in environments between 50 and 60 degrees C. 3._____ : Organisms that can be found growing at pH values below 4. 4.________ : Organisms that thrive in environments above 80 degrees C.
1. Halophiles : Organisms that thrive in salt concentrations of more than 25%. 2. Thermophiles : Organisms that thrive in environments between 50 and 60 degrees C. 3. Acidophiles : Organisms that can be found growing at pH values below 4. 4. Hyperthermophiles : Organisms that thrive in environments above 80 degrees C.
put in chronological order. A single plant cell is chosen to produce a plant that now produces Bt toxin. The gene for Bt toxin is isolated from the bacterium and inserted into the plasmid. The Ti plasmid is isolated and prepared for the insertion of foreign DNA. The plasmid is taken up by a bacterium. The bacterium is used to introduce the Bt toxin gene into the chromosome of plant cells.
1. The Ti plasmid is isolated and prepared for the insertion of foreign DNA. 2. The gene for Bt toxin is isolated from the bacterium and inserted into the plasmid. 3. The plasmid is taken up by a bacterium. 4. The bacterium is used to introduce the Bt toxin gene into the chromosome of plant cells. 5. A single plant cell is chosen to produce a plant that now produces Bt toxin.
Place the following statements in the correct order of events for replication of the leading strand.
1. double stranded DNA is unwound by helicase 2. proteins bind to the DNA in order to stabilize the single strands 3. Primase synthesizes an RNA primer 4. Hydrogen bonds form between the complementary bases 5. DNA polymerase catalyzes formation of a sugar-phosphate bond between neighboring nucleotides
A NEWLY ACQUIRED GENE
1. transformation introduced the penicillinase gene to this strain of Neisseria gonorrhoeae 2. recombination occurred, placing the penicillinase gene in the Neisseria gonorrhoeae genomre 3. The penicillinase gene was replicated along with all of the other DNA prior to cell division, resulting in the vertical transmission of the gene to daughter cells 4. the penicillinase gene was transcribed into mRNA 5. the penicillinase mRNA was translated into the protein penicillinase
Bacterium Y, which has a generation time of 30 minutes, was inoculated in a sterile nutrient broth. After 3 hours of incubation, there are 7 x 105 cells of Bacterium Y in the broth. How many cells of Bacterium Y were inoculated in the broth? Your answer must be in scientific notation with unit such as 1.6 x 10^2 cells. Round your answer to the nearest 10th. For example, your answer is 1.675 x 10^2 cells, type 1.7 x 10^2 cells. Put a space before and after the x. The x is lower case
1.1 x 10^4 cells
You are using a Petroff-Hausser counting chamber to determine the number of cells in a liquid culture. After diluting the original sample 10-fold, you place the dilution into the chamber. You count an average of 15 cells in five different squares. How many cells per mL were present in your original sample? Your answer must be in scientific notation such as 1.0 x 10^2. Round your answer to the nearest 10th. For example, your answer is 1.675 x 10^5 cells, type 1.7 x 10^5 cells. Put a space before and after the x. The x is lower case.
1.9 x 10^8 cells
Lytic Infection Cycle
1.Attachment 2.Penetration 3.Un-coating 4.Biosynthesis 5.Maturation 6. Release
Refer to figure below. What is the final dilution of tube 2? Your answer must be in fraction such as 1/10.
1/1000
The total magnification using a 10X ocular and a 100X objective would be (110/1000/10000)X. (Be sure your answer is a numeral.)
1000
As an epidemiologist, Dr. Thompson is interested in determining the frequency with which a specified event occurs within a particular population at a certain instant or during a particular period. This measure is known as a rate. In epidemiologic practice, an attack rate is the most commonly used method of determining the extent or frequency with which a disease is experienced by a population of individuals. In this instance, Dr. Thompson is interested in knowing what percentage of the individuals who attended the July 4 celebration became ill. What is the attack rate of food poisoning among the group who attended the July 4 celebration? 40/65(100)= 61.5% 65/105(100)= 61.9% 40/150(100)= 26.6% 105/150(100)= 70.0%
105/150(100)= 70.0%
Guacamole can be pasteurized by exposure to ________.
130,000 psi pressure
Based on the data supplied, what was the approximate mortality rate for this outbreak?
14% (43 / 300) ×× 100 = 14%
What is the time and temperature requirement of sterilization in dry heat ovens?
160oC-170oC for 2-3 h
If all the following DNA fragments were analyzed on an electrophoresis gel, which one would migrate farthest from the negative electrode?
250 base pairs
If all the following DNA fragments were analyzed on an electrophoresis gel, which one would migrate farthest from the negative electrode? a. 1000 base pairs b. 750 base pairs c. 250 base pairs d. 2500 base pairs e. 5000 base pairs
250 base pairs
At present, the organisms are grouped into _______ domains based on the differences in ________.
3 ; rRNA
What is the nucleotide sequence of the complementary strand of the DNA strand below? 5' AATTCGGA 3'
3' TTAAGCCT 5'
A DNA molecule is shown below. If the upper strand, is used as template to make RNA, what is the sequence of nucleotide of the RNA? 5' AGTTTGCAT 3' 3' TCAAACGTA 5'
3' UCAAACGUA 5'
One g of fecal matter was suspended in 9 ml saline solution (tube1). After mixing gently but thoroughly, one ml from tube 1 was removed and added to tube with 99 ml saline solution (tube 2). One ml suspension from tube 2 was plated in nutrient agar and after 24 h incubation, 45 bacterial colonies were counted. Determine cfu/g bacteria in the fecal sample. Your answer must be in scientific notation such as 1.0 x 10^2. Round your answer to the nearest 10th. For example, your answer is 1.675 x 10^5 cfu/g, type 1.7 x 10^5 cfu/g. Put a space before and after the x. The x is lower case.
4.5 x 10^4 cfu/g
A scientist is using an objective lens with 40X magnification on his microscope. If the ocular lens magnifies 10X, what is the total magnification being used to visualize the specimen?
400X
What is the total magnification if a protozoan is observed at 4x objective in a microscope with an ocular magnification of 10x? Your answer must be numeric with lowercase letter x such as 100x. Do not put a space between the number and the letter.
40x
At which point does a recipient cell become an F+ cell? 1. Fusion of the cell membranes 2. Attachment of the sex pilus 3. Transfer of the single stranded F factor 4. Pulling of donor and recipient cells together 5. Formation of the complementary strand of the F factor
5
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'
During elongation, how is the RNA synthesized?
5' to 3'
Which of the following correctly orders the successful application of epidemiology to control the emergence of SARS? 1. Sales restriction of civets and other wild food sources. 2. Containment and infection-control of virus in healthcare settings 3. Source of SARS traced to bats and civets. 4. Travel restricted to and from endemic areas. 5. Initial outbreak of SARS identified. 5, 4, 1, 3, 2 4, 5, 3, 2, 1 5, 3, 2, 4, 1 3, 5, 4, 2, 1
5, 3, 2, 4, 1
Refer to figure below and determine cfu/mL bacteria in the sample. Your answer must be in scientific notation with unit such as 1.0 x 10^2 cfu/mL. Round your answer to the nearest 10th. For example, your answer is 1.675 x 10^5 cfu/mL, type 1.7 x 10^5 cfu/mL. Put a space before and after the x. The x is lower case.
5.0 x 10^5 cfu/mL
If you started with a single DNA molecule, how many would you have at the end of six PCR cycles?
64
If you started with a single DNA molecule, how many would you have at the end of six PCR cycles? a. 64 b. 6 c. 32 d. 100 e. 16
64
RNA is composed of four nucleotides, A, U, C, and G. Each codon is composed of three nucleotides. The number of possible codons is
64.
A broth containing one million bacterial cells is treated with an antimicrobial agent that kills 90% of the cells in 1 minute. What is the minimum amount of time it will take before all the cells in the broth are dead?
7 minutes
A broth containing 1 million bacterial cells is treated with an antimicrobial agent that kills 90% of the cells in 1 minute. What is the minimum amount of time it will take before all the cells in the broth are dead?
7 minutes Because 90% of the cells present are killed each minute, the decline of the bacterial population gives a straight line when the experimental values are plotted on a semilogarithmic graph. The last cell will be killed at some point between 6 and 7 minutes of exposure.
Denaturation requires water and denaturation of proteins is the antimicrobial action of alcohol. Which of the following solutions of alcohol is more effective against COVID-19?
70%
What is the temperature used for the extension step?
72' C
What is the temperature used for the extension step?
72º C
Which of the following describes flash pasteurization?
72ºC FOR 15 SECONDS
If the MBC for a particular drug is 16 g/ml, which of the following serial dilutions of the drug is likely to be the MIC?
8 g/ml
If the MBC for a particular drug is 16 μμg/ml, which of the following serial dilutions of the drug is likely to be the MIC?
8 μμg/ml
Refer to figure below and determine MIC. Your answer must be numeric with % sign like 16%. Do not type a space between the number and %.
83%
What is the sequence of the temperatures of a typical PCR reaction?
94 °C, 60 °C, 72 °C
What is the sequence of the temperatures of a typical PCR reaction?
94' C, 60' C, 72' C
Which of the following would be an appropriate temperature for the first step of PCR?
94°C
Which of the following would be an appropriate sequence of temperatures for PCR?
94°C, 65°C, 72°C
Which of the following would be an appropriate sequence of temperatures for PCR? a. 72°C, 65°C, 94°C b. 94°C, 55°C, 37°C c. 94°C, 65°C, 72°C d. 65°C, 72°C, 94°C e. 94°C, 37°C, 55°C
94°C, 65°C, 72°C
Differentiate flagellum of Gram-negative bacteria from flagellum of Gram-positive bacteria?
A Gram-positive flagellum has only two rings in its basal body; Gram-negatives each have four.
How are Gram-positive and Gram-negative flagella different?
A Gram-positive flagellum has only two rings in its basal body; Gram-negatives each have four.
Based on the animation, what is transferred during bacterial conjugation?
A bacterial plasmid
Which of the following scenarios is an example of bacterial motility?
A bacterium moving towards a food source
What effect might a buildup of bilirubin have on a fetus?
A buildup of bilirubin may lead to severe neurological damage or death.
What is a zoonotic disease?
A disease that can spread from animals to humans.
You are a scientist and are studying how viruses attach to its host cell. You find a virus attachment area that is dense and full of fatty acid molecules. This area is most likely to be?
A lipid raft
Drag the labels onto the diagram to identify how nucleotides pair up. Labels can be used once, more than once, or not at all.
A pairs with T G pairs with C
What kind of bond is formed when two amino acids join together?
A peptide bond
In which of the following do the mucous membranes serve as a portal of entry for disease?
A person rubs the eye with contaminated fingers and the pathogen is washed into the nasal cavity by way of tears.
Which of the following is an example of the parenteral route?
A person steps on a nail.
Lipid raft
A portion of the plasma membrane of the host cells that contains increased numbers of receptors required for virus attachment
Which part of a plasmid vector is necessary to stimulate gene expression?
A promoter
Virion
A single viral particle is called a virion
What would happen if the DNA sequence that coded for Cys was mutated in the third position from a U to an A?
A stop codon would be introduced prematurely.
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.
Bacteriophage
A virus that infects bacteria
A person with type O blood can donate to individuals with which of the following blood types?
A, B, AB, or O
What type of staining can be used to detect the presence of bacteria causing tuberculosis?
Acid-fast staining
If a microbiologist omitted the decolorizer from a Gram-stained smear, which of the following would happen?
All cells in the smear would be purple.
Which of the following statements is NOT accurate about microbial DNA?
All of the DNA in eukaryotic cells is contained within a nucleus.
Which of the following statements is NOT accurate about prokaryotic and eukaryotic genomes?
All of the DNA in eukaryotic cells is contained within a nucleus.
What is the inducer molecule in the lac operon?
Allolactose
During the infection, there are many different environments that P. multocida will encounter. In order to cause an infection like the one in Sam's forearm, P. multocida must regulate its metabolic pathways in order to adapt to the changing environments. The process of glycolysis is regulated at several steps by allosteric inhibition. Which of the following are features of allosteric inhibition?
Allosteric inhibition can be reversed. Allosteric inhibition can be irreversible. The allosteric inhibitor binds to a site distinct from the active site resulting in decreased affinity of the enzyme for the substrate.
What is the function of the low temperature second step in PCR (polymerase chain reaction)?
Allowing primers to bind complementary sequences.
A particular drug works by interfering with cellular metabolism in Gram-negative bacteria. How might these bacteria become resistant in a way that Gram-positive bacteria never could?
Alter porin proteins in the cell's outer membrane
Which of the complement pathways employs properdin?
Alternative pathway
(Q) Bacteria that can grow in the presence or absence of oxygen (O2) are called _____. (1) facultative anaerobes (2) obligate anaerobes (3) microaerophiles (4) obligate aerobes
Answer: (1) facultative anaerobes. Extra: Facultative anaerobes are able to use oxygen if it is present but also to grow in the absence of oxygen, although with decreased efficiency.
(Q) Which of the following methods used to count microbes is correctly matched as direct or indirect? (1) filtration--direct method (2) dry weight--direct measurement (3) plate count--indirect measurement (4) turbidity--direct method
Answer: (1) filtration--direct method. Extra: A specific volume of fluid is filtered through a membrane, which is then placed on media and allowed to grow, representing a direct count of the viable cells.
(Q) Microbes have very narrow optimum temperature ranges. Which of the following classifications of microbes are most likely to cause human disease, based on temperature requirements? (1) mesophiles (2) hyperthermophiles (3) thermophiles (4) psychrophiles
Answer: (1) mesophiles. Extra: The temperature range of mesophiles overlaps that of normal human body temperature, allowing the greatest growth.
(Q) For which of the following types of microbes would a microbiologist use culture techniques for living host cells? (1) obligate intracellular organisms, such as chlamydia and viruses (2) capnophiles (3) normal skin bacteria (4) Campylobacteria sp.
Answer: (1) obligate intracellular organisms, such as chlamydia and viruses. Extra: These organisms cannot grow on media but require living host cells when cultured.
(Q) Bacterial growth measures increases in the size of a(n) _____________, while the growth of a multicellular organism refers to an increase in the size of a(n) _____________. (1) population; individual organism (2) individual organism; population (3) eukaryotic cell; prokaryotic cell (4) prokaryotic cell; eukaryotic cell
Answer: (1) population; individual organism
(Q) Prolonging Exponential Growth: A chemostat is continuous culture system that is designed to promote and prolong exponential growth and prevent bacteria from entering stationary phase. How might this work? (1) Chemostats include detoxifying agents that inactivate growth-inhibiting toxins that develop during continued microbial growth. (2) Chemostats provide a continued source of fresh nutrients and remove wastes and dead bacterial cells. (3) Chemostats promote the formation of endospores, which enable the long-term survival of the bacteria. (4) Chemostats include growth-promoting agents that prolong microbial growth.
Answer: (2) Chemostats provide a continued source of fresh nutrients and remove wastes and dead bacterial cells.
(Q) Bacterial generation times are typically measured using which units of time? (1) Months (2) Hours (3) Days (4) Seconds
Answer: (2) Hours
(Q) Which of the following statements regarding infections involving biofilms is FALSE? (1) It is estimated that nearly 70% of all infections are caused by biofilms. (2) There is no way to prevent biofilms from developing on surfaces. (3) Microbes in biofilms are 1000x more resistant to antimicrobials than are independent organisms. (4) The majority of hospital acquired infections (nosocomial infections) are related to biofilms.
Answer: (2) There is no way to prevent biofilms from developing on surfaces. Extra: This is false. Antimicrobials can be applied to the surface of catheters and IV tubing to prevent biofilm development.
(Q) Which of the following describes the correct equation used to calculate generation time? (1)(Number of cells at time zero) - (Number of cells at the end of a specified time) (2) Number of generations (doublings)/Total time (3) Total time/Number of generations (doublings) (4) (Number of cells at the end of a specified time) - (Number of cells at time zero)
Answer: (2) Total time / Number of generations (doublings)
(Q) Which of the following phases of the bacterial growth curve is matched with the correct definition? (1) death phase--the phase where the curve is flat; microbial deaths balance the number of new cells (2) log phase--the phase where organisms are actively dividing and the generation time is constant (3) lag phase--the phase where the death of organisms exceeds the creation of new cells and the curve declines (4) stationary phase--the phase where cells are not dividing very rapidly as they acclimatize to a new environment
Answer: (2) log phase--the phase where organisms are actively dividing and the generation time is constant. Extra: This is the steep upward slope of the bacterial growth curve, where organisms are rapidly multiplying.
(Q) Bacteria naturally prefer company instead of solitude for growth. Examples of this kind of communal growth pattern can be found everywhere, from surfaces of the teeth and the intestines, to the surface of a slimy rock in the lake, to the thick floc that clogs water pipes. These examples of communal bacterial growth are known by what name? (1) colony (2) infectious unit (3) biofilm (4) planktonic unit
Answer: (3) Biofilm. Extra: Biofilms are a large collection of mixed populations of organisms that form a matrix of "slime" for protection and assemble a complex, coordinated, and functional community on a surface. Biofilms often provide a safe haven for bacterial growth, often among "friendly" microorganisms. The complex architecture of biofilms gives the cells benefits they would not have in an individual lifestyle as a planktonic cell. As such, biofilms can play an extremely important role in colonizing a host and leading to a disease state.
(Q) Cultures of the Lake of the Ozarks water samples were grown on enrichment media for identification. However, these organisms are present to some degree in all samples. An important question from a clinical perspective is whether or not there is a significant increase in the fecal coliform populations that would put people's health at risk. If you were part of the team investigating this outbreak, how would you best enumerate the fecal coliform threat? (1) direct microscopic counts (2) plate count culture (3) filtration count culture (4) serial dilution count culture
Answer: (3) filtration count culture. Extra: This method will trap organisms and keep them on the surface of the filter. Transferring the organisms to a plate will then produce an accurate count.
(Q) Most fungi grow best at pH: A) 1. B) 5. C) 7. D) 9. E) 14.
Answer: B) pH 5 (Acidic)
(Q) Which of the following is NOT a step in bacterial cell division? A. Cell elongation B. Disappearance of nuclear envelope C. Splitting apart of two new daughter cells D. Replication of the genetic material
Answer: B. Disappearance of nuclear envelope
(Q) Sampling lake water for microscopic organisms is not as easy as it sounds when you want to both count and identify species. In a given water sample, your bacteria of choice can be rare or difficult to culture, particularly given the mixture of bacteria in a biofilm. Which of the following culture media would be best for growing fecal coliforms when they are relatively less abundant than other bacteria in the lake? (1) complex culture medium (2) anaerobic culture medium (3) basic culture medium (4) enrichment culture medium
Answer: (4) Enrichment Culture Medium. Extra: Growth of microorganisms for identification is not a trivial exercise. To accurately and efficiently grow bacteria in culture, you must consider the bacteria's relative abundance, metabolic and chemical needs, and best growth conditions, as well as the cost and overall goals of the experiment. Enrichment culture medium is a good choice for environmental samples whose desired populations are low compared to the rest of the microbes present. From a sample of large numbers of organisms, complex medium favors the growth of only certain organisms.
(Q) Which of the following statements accurately describes the culture media necessary for growing Clostridium tetani? (1) Nutrient agar contains ingredients that combine with oxygen and remove it, creating an anaerobic environment. (2) A complex medium is one whose exact chemical composition is known. (3) A chemically defined medium is one made up of extracts such as those from yeasts, meat, or plants whose exact chemical composition may vary slightly. (4) Reducing media are complex media containing chemicals, such as thioglycolate, that combine with oxygen, creating an anaerobic environment.
Answer: (4) Reducing media are complex media containing chemicals, such as thioglycolate, that combine with oxygen, creating an anaerobic environment. Extra: This medium is used to create an anaerobic environment for obligate anaerobes.
(Q) Bacteria are said to exhibit logarithmic, or exponential, growth. What does that mean about the growth rate of bacterial populations? (1) Every new cell is capable of producing two daughter cells. (2) The population size increases by a power of two. (3) The number of new cells is proportional to the size of the population (the larger the population gets, the faster it grows). (4) Since each and every bacterial cell is capable of reproduction, the size of a bacterial population increases by a power of two. In effect, the larger a population gets, the faster it grows.
Answer: (4) Since each and every bacterial cell is capable of reproduction, the size of a bacterial population increases by a power of two. In effect, the larger a population gets, the faster it grows.
(Q) Which of the following factors may affect the generation time? (1) Temperature (2) Growth media used (3) Bacterial species plated (4) Temperature, growth media, and bacterial species are all examples of factors that can affect generation time.
Answer: (4) Temperature, growth media, and bacterial species
(Q) When bacteria are inoculated into a new sterile nutrient broth, their numbers don't begin to increase immediately. Instead, there is a lag phase that may last for an hour or even several days. Why don't bacterial numbers increase immediately? (1) The medium contains inhibitors that prohibit rapid growth of the bacteria, and these must be inactivated before bacterial numbers will increase. (2) The bacteria have to establish a biofilm before their numbers can increase. (3) There are not enough nutrients for the bacteria to grow, and growth is delayed until there are some dead cells to cannibalize. (4) The bacteria must adjust to the nutrient content in the new medium, synthesizing necessary amino acids, growth factors, and enzymes.
Answer: (4) The bacteria must adjust to the nutrient content in the new medium, synthesizing necessary amino acids, growth factors, and enzymes.
(Q) Which of the following statements describes what is happening in the cell during the lag phase? (1) Nutrients are depleted from the media; the microorganisms die at a rapid & uniform rate. (2) Cells are undergoing binary fission, resulting in an exponential increase in the population size. (3) The number of cells that are dividing equals the number of cells that are dying. (4) The cells are adjusting to their new environment; cellular metabolism is accelerated.
Answer: (4) The cells are adjusting to their new environment; cellular metabolism is accelerated.
(Q) Which of the following statements describes what is happening in the cell during the stationary phase? (1) The cells are adjusting to their new environment; cellular metabolism is accelerated. (2) Nutrients have been depleted from the media; the microorganisms are dying at a rapid and uniform rate. (3) Cells are undergoing binary fission, resulting in an exponential increase in the population size. (4) The number of cells that are dividing equals the number of cells that are dying.
Answer: (4) The number of cells that are dividing equals the number of cells that are dying.
(Q) What is the definition of generation time? 1) The time span from the beginning of the log phase to the beginning of the stationary phase 2)The time it takes for one bacterium to produce a new circular chromosome 3) The time span from the beginning of the lag phase and the beginning of the log phase 4) The time required for the population to double in size
Answer: (4) The time required for the population to double in size
(Q) Why are multiple serial dilutions plated when using the direct method? (1) So there are extra plates for comparison between the direct and indirect methods (2) In case one culture becomes contaminated (3) To compare rates of growth on different growth media (4) To ensure that one dilution results in a plate with a countable number of colony-forming units (cfu)
Answer: (4) To ensure that one dilution results in a plate with a countable number of colony-forming units (cfu)
(Q) The depletion of essential metabolites and accumulation of toxic metabolic waste products results in the beginning of the _________________ phase. (1) lag (2) stationary (3) log (4) death
Answer: (4) death
(Q) Which of the following statements describes what is happening in the cell during the logarithmic (log) phase? 1) Cells are undergoing binary fission, resulting in an exponential increase in the population size. 2) Nutrients have been depleted from the media; the microorganisms are dying at a rapid and uniform rate. 3) The cells are adjusting to their new environment; cellular metabolism is accelerated. 4) The number of cells that are dividing equals the number of cells that are dying.
Answer: 1) Cells are undergoing binary fission, resulting in an exponential increase in the population size.
(Q) Which of the following represents an ideal number of colony-forming units for effective enumeration using the direct method? (1) 1,000,000 (2) 100 (3) 1,000 (4) 10
Answer: 100
(Q) Calculating Population Increases during Exponential Growth: This activity asks you to calculate the size of a bacterial population during exponential growth. A broth medium has been inoculated, and microbial numbers will be counted periodically to generate a bacterial growth curve. At 2 hours after inoculation, the culture has progressed through lag phase and is now in log phase. At this point, the population size is 1 million cells. The generation time is 30 minutes. Assuming the continuation of log growth, how many cells would there be at 2 hours of growth in log phase? (1) 32 million (2) 8 million (3) 16 million (4) 2 million (5) 4 million
Answer: 16 million. Extra There would be approximately 16 million cells. In the 2-hour interval of log growth, there are four 30-minute generations. This is four doublings of the 1 million organisms present at hour 2. 1 million cells x 24 = 16 million cells
(Q) Starting with three cells, how many cells would result from three rounds of replication? A. Six B. Nine C. Twelve D. Twenty-four E. Forty-eight
Answer: 24
(Q) What is the difference between the direct and indirect methods of determining generation time with a growth curve? 1) In the indirect method, only one plate is inoculated; in the direct method, several serial dilutions are plated. 2) In the indirect method, the cells are enumerated by determining colony-forming units on a Petri dish; in the direct method, the cell numbers are approximated using a spectrophotometer. 3) In the direct method, the cells are enumerated by determining colony-forming units on a Petri dish; in the indirect method, the cell numbers are approximated using a spectrophotometer. 4) In the direct method, only one plate is inoculated; in the indirect method, several serial dilutions are plated.
Answer: 3) In the direct method, the cells are enumerated by determining colony-forming units on a Petri dish; in the indirect method, the cell numbers are approximated using a spectrophotometer.
(Q) 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
Answer: 3-1-2-4
(Q) A sample of milk is tested for its bacterial content in a plate count assay. A one-milliliter sample of the milk is diluted in a 1:10 dilution series. One milliliter of the third dilution tube is plated in a pour plate. After incubation, the plate has 54 colonies, indicating that the original milk sample contained: A) 54 cells. B) 540 cells. C) 5400 cells. D) 54,000 cells. E) 540,000 cells.
Answer: 54,000 cells.
(Q) The addition of which of the following to a culture medium will neutralize acids? A) Buffers B) Sugars C) pH D) Heat E) Carbon
Answer: A) Buffers
(Q) Pathogenic bacteria isolated from the respiratory or intestinal tracts of humans are: A) capnophiles that grow best in carbon dioxide incubators. B) facultative anaerobes that require reducing media for growth. C) strict aerobes that grow best in candle jars. D) capnophiles that prefer highly oxygenated growth conditions. E) strict aerobes that grow best in reducing media.
Answer: A) capnophiles that grow best in carbon dioxide incubators.
(Q) A culture medium consisting of agar, peptone, and beef heart is a: A) complex medium. B) chemically defined medium. C) selective medium. D) reducing medium. E) differential medium.
Answer: A) complex medium.
(Q) How long does it take for the daughter cells from one round of replication to replicate themselves? A. 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. B. No time is needed -- the daughter cells cannot replicate further. C. 20 minutes D. After the cells have matured fully.
Answer: A. 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.
(Q) Which step of binary fission is the reason for genetically identical daughter cells? A. Replication of the bacterial chromosome B. Splitting of the two daughter cells C. Elongation of the cell D. There are four new daughter cells that result from one parental cell
Answer: A. Replication of the bacterial chromosome
(Q) Lag Phase: When bacteria are inoculated into a new sterile nutrient broth, their numbers don't begin to increase immediately. Instead, there is a lag phase that may last for an hour or even several days. Why don't bacterial numbers increase immediately?
Answer: A. The bacteria must adjust to the nutrient content in the new medium, synthesizing necessary amino acids, growth factors, and enzymes. Extra:A new medium may not have the same nutrients that were available in the medium from which an inoculum was taken. The bacteria may have to synthesize different amino acids, growth factors, or enzymes to enable them to grow in this new medium. Once those are synthesized, the growth rate is likely to increase, and the cells will move into log (exponential) growth phase.
(Q) Patients with indwelling catheters are susceptible to infections because: A. biofilms develop on catheters. B. injected solutions are contaminated. C. infections can be transmitted from other people. D. their immune systems are weakened. E. bacteria cause infections.
Answer: A. biofilms develop on catheters
(Q) What does a spectrophotometer directly measure? 1) Plate count in colony-forming units 2) Absorbance of light 3) Level of contamination 4) Bacterial growth
Answer: Absorbance of light
(Q) Which of these elements is NOT correctly matched with its cellular function? A) magnesium and potassium — required as cofactors for enzymes B) sulfur — used for synthesis of thiamin and biotin C) nitrogen — needed for amino acid synthesis D) phosphorus — incorporated into nucleic acids E) None of the answers is correct; all of the elements are correctly matched.
Answer: All of the answers are correctly matched.
(Q) During which growth phase will gram-positive bacteria be most susceptible to penicillin? A) Lag phase B) Log phase C) Death phase D) Stationary phase E) The culture is equally susceptible during all phases.
Answer: B) Log phase
(Q) Which of the following is the best definition of generation time? A) The length of time needed for lag phase B) The length of time needed for a cell to divide C) The minimum rate of doubling D) The duration of log phase E) The time needed for nuclear division
Answer: B) The length of time needed for a cell to divide
(Q) What would happen if the septum did not form during binary fission? A. The chromosome could not replicate. B. The parent cell would now have two copies of the chromosome. C. Nothing; the septum is not required for binary fission. D. The daughter cells would not be genetically identical.
Answer: B. The parent cell would now have two copies of the chromosome.
(Q) The biosafety level (BSL) for most introductory microbiology laboratories is: A) BSL-1. B) BSL-2. C) BSL-3. D) BSL-4.
Answer: BSL-1
(Q) Which level of biosafety (BSL) is appropriate for handling organisms that present a moderate risk of infection? BSL-3 BSL-1 BSL-2 BSL-4
Answer: BSL-2. Extra: BSL-2 labs feature open bench tops, lab coats, gloves, and appropriate eyewear for use in working with microbes that are moderately pathogenic.
(Q) In microbiology lab, you make three different culture plates: one general purpose plate, one selective media plate, and one differential media plate. Unfortunately, you forget to label the different plates, so you do not know which is which. To determine the identity of each plate, you inoculate it with two different strains of laboratory bacteria. Which of the following results would indicate the plate you used was the general purpose media? A. Both organisms would grow equally well. B. Only one organism would grow. C. Both organisms would grow, but they would be dyed different colors. D. Only one organism would grow, and it would grow a different color.
Answer: Both organisms would grow equally well.
(Q) The biosafety level for a clinical microbiology laboratory working with potentially airborne pathogens, like tuberculosis bacteria, is: A) BSL-1. B) BSL-2. C) BSL-3. D) BSL-4.
Answer: C) BSL-3.
(Q) Which of the following is an advantage of the standard plate count? A) Can readily count cells that form aggregates B) Requires incubation time C) Determines the number of viable cells D) Chemical and physical requirements are determined by media and incubation. E) Cannot be used to count bacteria in food
Answer: C) Determines the number of viable cells
(Q) Which of the following is an example of a metabolic activity that could be used to measure microbial growth? A) MPN B) standard plate count C) glucose consumption D) turbidity E) direct microscopic count
Answer: C) Glucose Consumption
(Q) Which of the following is an advantage of the direct microscopic count? A) Can readily count organisms that are motile B) Enumerates dead cells C) Requires no incubation time D) Sample volume is unknown. E) Requires a large number of cells
Answer: C) Requires no incubation time
(Q) C) The same number of cells in both Assume you inoculated 100 cells into 100 ml of nutrient broth. You then inoculated 100 cells of the same species into 200 ml of nutrient broth. After incubation for 24 hours, you should have: A) More cells in the 100 ml. B) More cells in the 200 ml. C) The same number of cells in both.
Answer: C) The same number of cells in both.
(Q) C) The term facultative anaerobe refers to an organism that: A) Doesn't use oxygen but tolerates it. B) Is killed by oxygen. C) Uses oxygen or grows without oxygen. D) Requires less oxygen than is present in air. E) Prefers to grow without oxygen.
Answer: C) Uses oxygen or grows without oxygen.
(Q) A sample of milk is tested for its bacterial content in a plate count assay. A one-millileter sample of the milk is diluted in a 1:10 dilution series. One milliliter of the third dilution tube is plated in a pour plate. After incubation, the plate has 54 colonies, indicating that the original milk sample contained: A. 540,000 cells. B. 540 cells. C. 54,000 cells. D. 54 cells. E. 5,400 cells.
Answer: C. 54,000 cells.
(Q) Three cells with generation times of 60 minutes are inoculated into a culture medium. How many cells are there after 5 hours? A. 900 B. 180 C. 96 D. 32 E. 15
Answer: C. 96
(Q) What enables the copied chromosomes to separate during binary fission? A. The septum splits the replicated chromosomes. B. The mitotic spindle drives the separation. C. The chromosomes are attached to different parts of cell membrane, which elongates and thus separates the chromosomes. D. The nuclear membrane dissolves.
Answer: C. The chromosomes are attached to different parts of cell membrane, which elongates and thus separates the chromosomes.
(Q) In one hospital, Pseudomonas aeruginosa serotype 10 infected the biliary tract of 10% of 1300 patients who underwent gastrointestinal endoscopic procedures. After each use, endoscopes were washed with an automatic reprocessor that flushed detergent and glutaraldehyde through the endoscopes, followed by a tap water rinse. P. aeruginosa 10 was not isolated from the detergent, glutaraldehyde, or tap water. What was the source of the infections? A. fecal contamination of the bile ducts B. bacterial cell walls in the water C. a biofilm in the reprocessor D. contaminated disinfectant
Answer: C. a biofilm in the reprocessor
(Q) In microbiology lab, you make three different culture plates: one general purpose plate, one selective media plate, and one differential media plate. Unfortunately, you forget to label the different plates, so you do not know which is which. To determine the identity of each plate, you inoculate it with two different strains of laboratory bacteria. After inoculation, you see that a particular plate has allowed both organisms to grow, but one has changed color. Which plate do you think this is? A. It is impossible to distinguish between selective and differential media in this case. B. selective media C. differential media D. general purpose media
Answer: C. differential media
(Q) The term aerotolerant anaerobe refers to an organism that: A. uses oxygen or grows without oxygen. B. is killed by oxygen. C. does not use oxygen but tolerates it. D. requires more oxygen than is present in air. E. requires less oxygen than is present in air.
Answer: C. does not use oxygen but tolerates it
(Q) Thirty-six colonies grew in nutrient agar from 1.0 ml of undiluted sample in a standard plate count. How many cells were in the original sample? A) 4 B) 9 C) 18 D) 36 E) 72
Answer: D) 36
(Q) An experiment began with 4 cells and ended with 128 cells. How many generations did the cells go through? A) 64 B) 32 C) 6 D) 5 E) 4
Answer: D) 5
(Q) Salts and sugars work to preserve foods by creating: A) Depletion of nutrients. B) Hypotonic environment. C) Lower osmotic pressure. D) Hypertonic environment. E) Lower pH.
Answer: D) Hypertonic environment.
(Q) D) Metabolic activity Which of the following is NOT a direct method to measure microbial growth? A) Direct microscopic count B) Standard plate count C) Filtration D) Metabolic activity E) MPN
Answer: D) Metabolic activity
(Q) Which enzyme catalyzes the reaction: O2- + O2- + 2H+ → H2O2 + O2? A) Catalase B) Oxidase C) Peroxidase D) Superoxide dismutase
Answer: D) Superoxide dismutase
(Q) Which of the following pairs is mismatched? A) hyperthermophiles — growth at 85°C B) psychrotroph — growth at 0°C C) psychrophile — growth at 15°C D) thermophile — growth at 37°C E) mesophile — growth at 25°C
Answer: D) Thermophile → growth at 37°C
(Q) Which of the following is an organic growth factor? A) glucose B) NH₄H₂PO₄ C) peptone D) vitamin B1 E) H₂O
Answer: D) Vitamin B1
(Q) A culture medium on which only gram-positive organisms grow and a yellow halo surrounds: Staphylococcus aureus colonies is called a(n): A) enrichment culture. B) selective medium. C) differential medium. D) selective and differential medium. E) differential and enrichment culture.
Answer: D) selective and differential medium.
(Q) If cells are grown in media containing amino acids labeled with radioactive nitrogen (15N), most of radioactivity will be found in the cells. A. DNA. B. proteins. C. phospholipids. D. DNA and proteins. E. DNA and phospholipids
Answer: D. DNA and proteins
(Q) What results when a single bacterium reproduces? A. One parent cell and a genetically identical daughter cell B. One parent cell and a genetically different cell C. Two genetically identical daughter cells D. Two genetically unique daughter cells
Answer: D. Two genetically unique daughter cells
(Q) Which group of microorganisms is most likely to spoil a freshwater trout preserved with salt? A) thermophiles B) anaerobes C) psychrophiles D) hyperthermophiles E) facultative halophiles
Answer: E) Facultative Halophiles
(Q) If you begin with six cells, how many cells would you have after three rounds of division? A. Twelve cells B. Nine cells C. Eighteen cells D. Twenty-four cells E. Forty-eight cells F. It is impossible to determine.
Answer: E. Forty-eight cells
(Q) T or F: In performing a ten-fold dilutions series from a sample containing 10,000 bacteria per milliliter, the fourth tube in the dilution series will have 10 cells per milliliter.
Answer: False
(Q) T or F: Most pathogenic bacteria are thermophiles.
Answer: False
(Q) This activity asks you to consider various methods of counting or estimating the size of bacterial populations and to select the method that will provide the most accurate data for plotting a bacterial growth curve. Which of the following methods would be most appropriate for gathering data to plot a bacterial growth curve throughout the four phases? (1) direct microscopic count (2) indirect estimate based on turbidity (3) plate count (4) Any of these methods will provide reliable data for plotting a growth curve. (5) electronic cell counter
Answer: Plate Count. A plate count will provide the number of living cells. These data are most appropriate for generating a plot of a bacterial growth curve.
(Q) Why must a new pipette be used for each dilution when plating a serial dilution? 1) To avoid contamination from non-sterile pipettes 2) To avoid contamination from environmental organisms 3) To make sure organisms from the previous dilution are not carried over into the next dilution 4) To practice proper pipetting techniques
Answer: To make sure organisms from the previous dilution are not carried over into the next dilution
(Q) T or F: Agar is used as a solidifying agent in microbiological media since few bacteria can degrade it.
Answer: True
(Q) T or F: An isolated colony on a streak plate contains millions or billions of identical cells.
Answer: True
(Q) T or F: Bacterial growth refers to an increase in the numbers of cells in a bacterial culture.
Answer: True
(Q) T or F: Laboratory cultivation of obligate anaerobes requires reducing media or special growth chambers filled with inert gases.
Answer: True
(Q) T or F: Turbidity is an indirect measurement of bacterial growth that can be measured using a spectrophotometer.
Answer: True
(Q) Most bacteria grow best at pH: A) 1. B) 5 C) 7. D) 9. E) 14.
Answer: c) pH 7 (Neutral)
(Q) Which process is best for the short-term storage of bacterial cultures? (1) lyophilization (2) deep-freezing (3) freeze-drying (4) refrigeration
Answer: refrigeration Extra: Refrigeration is the best short-term storage method for microbes. Refrigeration slows down metabolic activity, but the microbes can be quickly revived at optimum temperatures.
Which of the following would be a useful phenotypic marker on a vector?
Antibiotic resistance gene
Although cholera can be treated with antibiotics, data suggest that antibiotic treatment alone is NOT the most effective therapy. Which of the following statements describes the most likely reason for supplementing antibiotic therapy? The production of cholera toxin helps V. cholerae resist antibiotic treatment. Antibiotic therapy addresses only the growth of V. cholerae; it doesn't address the extreme dehydration suffered by a person infected with V. cholerae. Because V. cholerae is a gram-negative organism, it is not very effectively treated with antibiotics. As with V. cholerae, the acidic environment of the stomach can have a negative impact on antibiotic activity.
Antibiotic therapy addresses only the growth of V. cholerae; it doesn't address the extreme dehydration suffered by a person infected with V. cholerae.
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.
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. Health care workers being treated with antibiotics may pass the antibiotic on to the patient. Visitors currently being treated with antibiotics can pass them on to the patient.
Antibiotics can be used in aerosols, thereby entering the environment.
Why are antibiotics often ineffective in treating food poisoning (food intoxication)? Oral antibiotics are degraded by stomach acid and, therefore, do not work well in the digestive tract. Pathogens in food pass through the digestive tract too rapidly to be targeted by antibiotics. Food poisoning is caused by viruses, which are not targeted by antibiotics. Antibiotics target bacteria; they do not damage toxins.
Antibiotics target bacteria; they do not damage toxins.
A response that is uniquely directed against pathogenic Bordetella pertussis would involve what component?
Antibodies
Bacillus anthracis is an endospore-forming bacterium. Which of the following is most likely? B. anthracis uses spores to reproduce, which develop into new offspring capable of causing anthrax. B. anthracis spores require a moist environment in order to stay dormant for an extended time. These spores will germinate and be capable of causing anthrax when they dry out. B. anthracis spores can remain dormant for hundreds of years without needing nutrients, remaining capable of causing anthrax when they germinate. B. anthracis spores can be killed by boiling water or ultraviolet light, so these can be used to prevent anthrax.
B. anthracis spores can remain dormant for hundreds of years without needing nutrients, remaining capable of causing anthrax when they germinate.
Which of the following microorganisms can be used as a biological insecticide? Bacillus thuringiensis Penicillium Escherichia coli Pseudomonas syringae
Bacillus thuringiensis
What type of nosocomial infection is likely to arise from intravenous catheterizations?
Bacteremia
What type of nosocomial infection is likely to arise from intravenous catheterizations? Bacteremia Urinary tract Lower respiratory Surgical Cutaneous
Bacteremia
How can capsules enable bacteria to evade the immune system? Capsules block the complement biding sites on the surface of the pathogen. Capsules can bind up IgA, rendering it inactive. A capsule is a superantigen that distracts the immune system.
Capsules block the complement biding sites on the surface of the pathogen.
Penicillin and other β-lactam antibiotics inhibit cell-wall synthesis. What makes them effective at killing bacterial cells? Bacteria are generally hypertonic relative to their environment, so they desiccate when their cell wall is weakened by the action of these antibiotics. Bacteria are generally hypotonic relative to their environment, so they burst when their cell wall is weakened by the action of these antibiotics. Bacteria are generally hypertonic relative to their environment, so they burst when their cell wall is weakened by the action of these antibiotics. Bacteria may burst or desiccate when their cell wall is weakened by the action of these antibiotics.
Bacteria are generally hypertonic relative to their environment, so they burst when their cell wall is weakened by the action of these antibiotics.
Which of the following explains why treatment of symptomatic tetanus requires an antitoxin and an antibiotic? It is always better to use multiple treatments to elicit a stronger response. Because the toxin is within the cell wall of the bacteria, it can only be eliminated by killing the bacteria. Because C. tetani bacteria excrete tetanus toxin, it is important to neutralize the toxin while also killing the bacteria that are producing more. The tetanus toxin binds irreversibly, causing damage to axons. The only way to heal the axons is with an antitoxin.
Because C. tetani bacteria excrete tetanus toxin, it is important to neutralize the toxin while also killing the bacteria that are producing more.
Explain why mycobacteria are the most resistant of all other vegetative bacteria.
Because of the presence of mycolic acids.
Why prevalence of a disease always exceeds incidence of a disease?
Because prevalence includes old and new cases.
Why viruses are called acellular obligate intracellular parasites?
Because they are not cells Because they replicate only inside their host cells.
The peptidoglycan cell wall and the one or two membranes present also impart a three-dimensional shape to the bacterial cell. The overall shape and arrangement of bacteria are genetically determined, so that each genus of bacteria has a characteristic shape (round, rod, spiral, etc.) and arrangements of the growing cell population (individual cells, chains of cells, or clustered cells). Drag the descriptive terms to the pictured bacterial shapes.
Bin 1: coccus (round) Bin 2: bacillus (oval) Bin 3: staphylococcus (grapes) Bin 4: streptobacillus (links) Bin 5: Vibrio (tube) Bin 6: spirochete (spiral)
Non-Enveloped Virus (binding)
Binding takes place between viral capsid and receptor
Enveloped Virus (binding)
Binding takes place between viral envelope proteins and receptor
Which of the pairs below are matched correctly for these clostridial pathogens involved in food poisoning? C. perfringens: produces enterotoxin C. botulinum: produces endotoxin C. perfringens: requires only a small number of cells to produce toxin C. botulinum: must grow in the body to produce toxin
C. perfringens: produces enterotoxin
During infection, C. diphtheriae expresses a variety of genes that are used to establish infection and cause disease. One of these genes encodes for diphtheria toxin. Expression of the toxin requires the genetic information contained in DNA be converted into protein. The 1st step in this process is transcription, in which DNA is converted into mRNA. The following is a short piece of the DNA sequence for diphtheria toxin (written 5' to 3'): TAA GCG TAG AAC TTG. Which of the following sequences represents the mRNA (written 5' to 3') that will be generated from this DNA sequence?
CAA GUU CUA CGC UUA
Which of the following restriction enzyme sites would produce blunt-ended fragments (the arrow represents the cutting site of the enzyme)?
CCC?GGG
Which of the following restriction enzyme sites would produce blunt-ended fragments? (The arrow represents the cutting site of the enzyme.)
CCC↓GGG
Which of the following restriction enzyme sites would produce blunt-ended fragments? (The arrow represents the cutting site of the enzyme.) a. CCC↓GGG b. C↓CGG c. A↓AGCTT d. G↓AATTC e. G↓GATCC
CCC↓GGG
What is the name of the glycoprotein molecule on helper T cells that recognizes and binds to MHC class II?
CD4
Which event happens first during cytotoxic T-cell activation?
CD8 binds to MHC molecules of infected cells
Which of the following can release histamines?
Cells from damaged tissues and the complement pathway
What would a virally infected skin epithelial cell have on its cell surface?
Class I MHC with skin cell antigens
After exogenous antigens are broken into smaller pieces, the epitopes are bound in what MHC protein and in what cell organelle?
Class II MHC, golgi body
What purpose does clonal deletion serve?
Clonal deletion destroys T cells with receptors complementary to the body's normal autoantigens.
Everyone, but particularly individuals who are farmers, gardeners, foresters, or others who spend significant time outdoors, are urged to adhere to a tetanus booster vaccinations schedule, receiving a booster if planning to travel and cannot remember when his or her last one. Why? Clostridium tetani typically causes infection when a wound is contaminated with soil, it's natural habitat. Accidental ingestion of Clostridium tetani toxin would lead to rapid onset of symptoms and an inability to call for help. Clostridium tetani typically causes infection when it produces quick-acting exotoxins that affect the nervous system. Quick treatment would not be available to victims who succumb far from help. There are no antibiotics available to treat this bacterial infection.
Clostridium tetani typically causes infection when a wound is contaminated with soil, it's natural habitat.
Which of the following statements regarding competitive inhibitors is true?
Competitive inhibitors decrease the rate of enzyme activity.
What enables competitive inhibitors to bind to a specific enzyme?
Competitive inhibitors have structures that resemble the enzyme's substrate.
What does cDNA stand for?
Complementary DNA
Which of the following statements concerning sticky-ended fragments is most likely to be true?
Complementary sticky-ended fragments were probably cut by the same restriction enzyme.
Which of the following statements are false?
Contamination is always followed by infection. Infection comes first before contamination. Every time there is an infection, disease always follows.
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.
The procedure used to identify individuals by their unique genetic sequences is known as a. microarray analysis. b. northern analysis. c. xenotransplantation. d. DNA sequencing. e. DNA fingerprinting.
DNA fingerprinting
The procedure used to identify individuals by their unique genetic sequences is known as ________.
DNA fingerprinting
Quinolones and fluoroquinolones act against what bacterial target?
DNA gyrase
Differentiate DNA from RNA.
DNA is double stranded while RNA is single stranded. DNA has thymine which is not found in RNA.
What characteristic of DNA allows two connected DNA polymerases to synthesize both the leading and lagging strands?
DNA is flexible.
Which type of molecule serves as a template during transcription, and which type of molecule is synthesized?
DNA is the template during transcription, and RNA is synthesized.
The enzyme __________ is used for connecting DNA fragments.
DNA ligase
Which of the following attaches the target gene to a desired location?
DNA ligase
A scientist who wants to monitor gene expression occurring in microbial cells under certain environmental conditions should use which of the following techniques?
DNA microarrays
A scientist who wants to monitor the gene expression occurring in microbial cells under certain environmental conditions should use which of the following techniques?
DNA microarrays
What is the genetic material of the virus?
DNA or RNA
Which enzyme is responsible for replacing RNA primers on newly synthesized DNA strands and is needed much more frequently on the lagging strand than on the leading strand?
DNA polymerase I
Synthetic nucleic acids are useful as a. DNA probes. b. DNA probes, primers, and antisense RNAs. c. antisense RNAs. d. DNA probes and antisense RNAs. e. primers for PCR.
DNA probes, primers, and antisense RNAs
Synthetic nucleic acids are useful as
DNA probes, primers, and antisense RNAs.
If a researcher used Escherichia coli DNA polymerase instead of Thermus aquaticus DNA polymerase in the PCR procedure, what would be the result? a. DNA replication would stop after one cycle. b. DNA replication would occur twice as fast as normal. c. Many mistakes would occur. d. DNA replication would occur more slowly than normal. e. DNA replication would not occur at all.
DNA replication would stop after one cycle
If a researcher used Escherichia coli DNA polymerase instead of Thermus aquaticus DNA polymerase in the PCR procedure, what would be the result?
DNA replication would stop after one cycle.
According to the animation, on what day does IgM first appear?
Day five
When an individual has severe diarrhea, as can occur with cholera, rehydration solution with glucose, salt, sodium bicarbonate, and potassium chloride can be administered. Why is it important to use a solution like this rather than simply giving the individual water? Hints The salt helps to reduce bacterial contamination and spoilage of the rehydration fluids. This type of solution is hypertonic to human body fluids and, therefore, causes water to flow into cells. It is not necessary; water would be equally effective. Patients suffering from diarrhea loose mainly water through their stools, and dehydration is dangerous. Diarrhea causes the loss of electrolytes, not just fluids. It is important to replace the electrolytes as well as the water.
Diarrhea causes the loss of electrolytes, not just fluids. It is important to replace the electrolytes as well as the water.
What test compares known concentrations of the drug with the patient samples?
Diffusion bioassay
What is DOT?
Directly Observed Therapy
Which of the following is NOT a step in bacterial cell division?
Disappearance of nuclear envelope
Many MRSA strains are sensitive to other antibiotics. Which of the following methods would be the best way to evaluate sensitivity to other antibiotics?
Disk diffusion
What domain/s composed the prokaryotes?
Domains Bacteria and Archaea
Why will the microbiota in the vagina of a woman of reproductive age differ from that of the same woman before puberty and after menopause? During the reproductive years, bacterial community in the vagina changes every month due to menstruation. Before puberty and after menopause, the vagina is colonized primarily by Lactobacillus acidophilus, which creates an acidic environment through fermentation. During the reproductive years, bacteria are introduced to the vagina during intercourse and colonize the mucosa. Before puberty and after menopause the vagina is sterile. During the reproductive years, the vagina contains significant amounts of glycogen that is fermented by Lactobacillus acidophilus to produce lactic acid, creating an acidic environment. Glycogen is absent before puberty and after menopause. During the reproductive years, the vagina is colonized only by Lactobacillus acidophilus, which produces lactic acid by fermentation, creating an acidic environment. Before puberty and after menopause the vagina is alkaline.
During the reproductive years, the vagina contains significant amounts of glycogen that is fermented by Lactobacillus acidophilus to produce lactic acid, creating an acidic environment. Glycogen is absent before puberty and after menopause.
What makes agglutination by antibodies possible?
Each antibody has at least two antigen-binding sites.
How are restriction enzymes named?
Each is named with letters referring to the genus, species, and strain of the source prokaryote and a Roman numeral denoting the order of its discovery.
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.
How could this epidemic be stopped without firing the worker?
Educate the worker about personal hygiene and use of an outhouse or designated bathroom. Instruct him to thoroughly wash his hands with clean soap and water after using the facilities.
Which of the following does not spread drug resistance throughout a population of bacteria?
Efflux pumps
Compare and contrast three metabolic pathways by choosing whether the statement applies to fermentation. Check all that apply.
End products may include lactic acid or ethanol. The coenzyme NAD+ plays an important role in the pathway. Process includes glycolysis Can generate ATP in the absence of O2. A total of 2 ATP are produced per molecule of glucose input.
Which of the following are true about exotoxin and/or endotoxin?
Endotoxin is produced only by Gram negative bacteria. Exotoxins are proteins that are secreted by G+ or G- in their surroundings.
Why do all enzymatic reactions need activation energy?
Energy is required to disrupt a substrate's stable electron configuration.
Why are enzymes important to biological systems?
Enzymes decrease the amount of activation energy required for chemical reactions to occur.
What is meant by the statement "Enzymes are biological catalysts"?
Enzymes speed up the chemical reactions in living cells.
Which scientific names are properly written?
Escherichia coli - Italic font Escherichia coli - Underlined with space b/w names
Which bacteria involved in food infections produce toxins to cause host damage? Listeria and Escherichia coli Listeria and Salmonella Campylobacter and Escherichia coli Escherichia coli and Salmonella
Escherichia coli and Salmonella
Clostridium tetani is an obligate anaerobe that can cause tetanus. When it enters the human body, it can produce tetanus toxin. Considering that C. tetani is an obligate anaerobe, which of the following explains how it can survive and cause disease in the human body? Especially in deep wounds, C. tetani can sometimes survive in areas with damaged tissue that have become anoxic because of poor-to-no blood flow. It doesn't survive but instead simply releases toxin as it dies. C. tetani can't access atmospheric oxygen, so it can grow as long as it stays on the surface of the skin rather than in well-oxygenated deeper tissues. C. tetani can only survive when other bacteria are available to consume oxygen and to keep oxygen levels low.
Especially in deep wounds, C. tetani can sometimes survive in areas with damaged tissue that have become anoxic because of poor-to-no blood flow.
Which of the following statements is MOST correct regarding the development of antibiotic resistance in populations of bacteria?
Exposure to antibiotics selects for the members of a bacterial population which already have a resistant phenotype.
Membrane transport refers to the mechanisms by which solutes cross the plasma membrane, but there are additional prokaryotic cell structures through which a solute would pass when entering or exiting a cell. Sequence the path of a solute from the external environment to the cytoplasm of a prokaryotic cell.
External Environment capsule cell wall plasma membrane Cytoplasm
Which of the following statements about extremophiles is FALSE? Extremophiles can be found in environments with high salinity, such as the Great Salt Lake, or with low temperatures, such as the Antarctic. Extremophiles can include members of the Bacteria or Archaea that live in extreme environments. Extremophiles are generally pathogenic to humans. Extremophiles use specialized enzymes in their metabolic pathways.
Extremophiles are generally pathogenic to humans.
What is required by an F- cell to become an F+ cell?
F plasmid
At the end of F plasmid conjugation, the recipient cell becomes (F+ or F-)?
F+
Gene therapy for human genetic diseases has not been successful yet.
FALSE
A cell wall is a requirement for all living bacteria.
False
At this point in writing your tutorial, you have to find a way to get across to the students the importance of a cell wall to a bacterium. How do you convey that the bacterial cell will be at the mercy of its environment? The cell wall will need to act as a support mechanism to neutralize the inflow or outflow of water that would alter the shape of the cell. The cell cannot search out for a better place in the environment that has more available water; or if there is water that it has a high enough solute concentration that the cell will not gain water. Because that's the problem for a bacterial cell, it cannot control the tonicity due to solute concentrations in the surrounding water. Water will flow in or out depending on solute concentrations and the only thing a bacterial cell can do to keep from collapsing due to water loss or rupturing due to too much water coming in is to have a strong cell wall that will hold its shape regardless of the osmotic pressures. The rigidity of the cell wall will maintain a set shape regardless of water flow. The proteins and lipids that anchor the cytoplasmic membrane to the cell wall will tether the membrane to the peptidoglycan layer so that when environmental conditions result in the loss of water from the cell, the membrane will not collapse in on itself. Similarly, changes in environmental conditions that would result in the inflow of water would expand the volume of the cell to the limits of the cell wall and no more.The composition of the cell wall allows for the expansion and contraction of the cell wall in response to the gain or loss of water from the cell.
False
Robert Koch sought a "magic bullet" for the treatment of disease caused by bacteria.
False
With the description of the different cell walls, membranes, and associated proteins set in the students' minds, you now need to introduce them to the idea that the cell wall can also act as a foundation to build things upon. Bacterial appendages require a strong foundation that will offer the support needed to move and function in a dynamic world. For example, flagella are long, whiplike protein structures that are used by many Gram-positive and Gram-negative bacteria for locomotion. In order to function effectively, a flagellum must be firmly anchored to the cell wall. How will you be able to get across the idea that the peptidoglycan cell wall is strong enough to support such a mechanism? With a protein rod that passes through the cell wall and protein rings used to anchor it in the membranes, these basal bodies are the rudimentary biological motors that use ATP power to spin the hook and the flagella attached to it.Bacterial flagella have a biological motor that spins within the cell wall and is powered by ATP. This allows the flagella to spin in a whiplike motion to propel the bacterium.
False
At which point does a recipient cell become an F+ cell?
Formation of the complementary strand of the F factor
If you begin with six cells, how many cells would you have after three rounds of division?
Forty-eight cells
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.
__________ cells would be expected to be the most susceptible to the action of polyene drugs such as amphotericin B, while __________ cells would be the least susceptible.
Fungal; bacterial
Which of the following is a DNA strand complementary to CGA ATC AGC?
GCT TAG TCG
Which of the following would be a likely cutting sequence for a restriction enzyme?
GTTAAC
How is generalized transaction different from specialized transduction?
Generalized transduction is initiated during lytic cycle of a virulent bacteriophage; specialized transduction is initiated during the lysogenic cycle of a temperate bacteriophage
__________ can be used to advise prospective parents about their risk of transmitting genetic disorders, such as Huntington's disease, to their offspring. Polymerase chain reaction Vaccine production Genetic screening Gene therapy
Genetic screening
Bt crops, including potatoes and cotton, are genetically engineered using laboratory techniques. Which of the following utilizes recombinant DNA technology to produce advantageous traits in the crops that are produced?
Genetically engineered crops have an advantageous gene from another organism inserted into their genome
Bt crops, including potatoes and cotton, are genetically engineered using laboratory techniques. Which of the following utilizes recombinant DNA technology to produce advantageous traits in the crops that are produced? Genetically engineered crops have natural characteristics that give them a genetic advantage. Genetically engineered crops have a genetic advantage because the parent strains have advantageous traits. Genetically engineered crops have an advantageous gene from another organism inserted into their genome. Genetically engineered crops naturally produce larger plants and bountiful products.
Genetically engineered crops have an advantageous gene from another organism inserted into their genome.
Which of the following is not a result of histamine release?
Glomerulonephritis
Acetobacter can oxidize ethanol to produce acetic acid. Another bacterium that does this is Lactobacillus. Gluconobacter. Saccharomyces. Streptococcus.
Gluconobacter
At the doctor's office, the doctor drains the abscess and takes a sample for culturing. She also prescribes some broad-spectrum antibiotics to treat the obvious infection. A couple days later, the doctor tells Sam that his wound contained a number of bacteria including Pasteurella multocida. When the dog bit Sam's arm P. multocida entered the wound and started to establish an infection. In order to do so, the bacteria have to grow, which requires energy. One of the most common energy sources used by bacteria is glucose. Why is glucose such a good source of energy for bacteria?
Glucose is a highly reduced compound, containing many carbon-hydrogen bonds and a lot of potential energy.
Consider the glycolysis pathway. Select all statements that correctly describe glycolysis.
Glyceraldehyde 3-phosphate is oxidized, and NAD+ is reduced to NADH. Glucose is the original electron donor. The 6-carbon skeleton of glucose is enzymatically split into two 3-carbon compounds More ATP is formed than is consumed in this process.
What does the plasma membrane of a phagocyte attach to on a microorganism?
Glycoproteins
After Gram staining, E. coli are pink in color. This result is interpreted as __________.
Gram negative
The thickness of this sugar-protein scaffold of peptidoglycan can be used to separate most bacteria into two groups. In your tutorial, you want to illustrate to the students that the thickness of the peptidoglycan layer can be used by microbiologists to differentiate many bacteria by only using an easy staining method that all microbiologists will have to master. This staining procedure, known as the Gram stain, is based on the retention of dyes within the cell wall for a positive result or the rinsing away of the dyes and leakage of the membrane for a negative result. A thicker cell wall will allow for retention of dye crystals that will give the bacterial cell a blue-purple color (positive result), but the thinner cell walls will not allow for the retention of these crystals during rinsing, which will mean that these cells will then be colorless unless another dye that does not require interaction with the cell wall to maintain its retention is used (negative result). In addition to differences in cell wall thickness, Gram-positive and Gram-negative bacteria also differ in the proteins and lipids associated with their cell walls, as well as the composition of their cell membranes. Gram-positive walls are composed of an underlying cytoplasmic membrane, with the thick peptidoglycan layer on the outside offering support. Proteins anchor the membrane and the cell wall together to provide support and structure between the two. Gram-negative staining walls have a different layout. You try to explain in your tutorial that even though these bacteria stain "negative" they do have a thin layer of peptidoglycan sandwiched in between two lipid bilayer membranes.
Gram positive bacterial cell wall: thick layer of peptidoglycan teichoic acids single lipid bilayer membrane Gram-negative bacterial cell wall: thin layer of peptidoglycan periplasmic space lipopolysaccharides dual lipid bilayer membranes
Which of the following are paired INCORRECTLY?
Gram: cholera
Which molecule triggers apoptosis?
Granzyme
If the unknown bacterium is a facultative anaerobe, mesophile and neutrophile, which conditions below will allow the unknown bacterium to grow in the laboratory?
Grow the bacterium in a culture medium which has a pH of 6.9 and incubate at 36oC with oxygen.
Match the processes with their description.
Growth B. increase in size Reproduction D. increase in number Responsiveness E. ability to react to stimuli Metabolism A. chemical reactions of organisms
What was the scientific result of Frederick Griffith's experiments with Streptococcus pneumoniae?
He showed that the DNA from strain S cells could transform strain R cells.
What is the process by which microbes are air dried and "attached" to a microscope slide using flame?
Heat fixation
What lymphocytes are involved in humoral immunity?
Helper T and B lymphocytes
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.
The Influenza virus uses which of the following for attachment?
Hemagglutinin
How does an F+ cell differ from an Hfr cell?
Hfr strains have the F plasmid integrated into the chromosome.
Please recall what you have learned about microbial metabolism and food processing methods and choose the best method for prevention of food spoilage for the food type below. There is a photo of different types of cheese. Use of salt or sugar to draw water out of foods (preservatives). High-heat treatment for a short period of time (pasteurization). Use of more than one food processing type (for example, canning and use of preservatives). Packaging into cans and jars and exposure to high heat under pressure (canning). Freezing and vacuuming to dry foods (lyophilization).
High-heat treatment for a short period of time (pasteurization).
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How does resistance to drugs spread in bacterial populations?
Horizontal gene transfer between bacteria spreads R (resistance) plasmids.
Lytic Infection
Host cell fills with new visions and bursts
Infection
Host cell must be permissive for infection to occur. It must contain all the components required to make a virion.
Attachment 1/2
Host cell receptors are used to facilitate virus attachment and entry into host cells.
Humans have species resistance to feline immunodeficiency virus for which of the following reasons?
Human cells do not have the chemical receptors required for attachment by feline immunodeficiency virus.
Why are chemotherapeutic agents that work on the peptidoglycan cell wall of bacteria a good choice of drug?
Humans and other animal hosts lack peptidoglycan cell walls.
Why are chemotherapeutic agents that work on the peptidoglycan cell wall of bacteria a good choice of drug? Bacteria are especially sensitive to these compounds. Humans and other animal hosts lack peptidoglycan cell walls. The drugs also work against DNA gyrase.
Humans and other animal hosts lack peptidoglycan cell walls.
The common cold virus (rhinovirus) uses which of the following for attachment?
ICAM molecules
The events of binary fission are I. the cell doubles in size II. the DNA is replicated III. the cell forms a septum IV. the cell separates from its offspringThe CORRECT order of these events is
II, I, III, IV
Put the following steps in the correct order needed to produce a recombinant vector containing a human gene insert. I. Introduce the recombinant plasmid into a bacterial cell. II. Isolate the human gene and the vector DNA using restriction enzymes. III. Ligate the DNA fragments to produce a recombinant plasmid. IV. Grow bacterial cells on a medium containing a selective agent (such as an antibiotic).
II, III, I, IV
What is the CORRECT order for the application of Koch's postulates?I. Inoculate suspect agent into test subject and observe that subject develops disease of interest .II. Isolate and culture suspect agent in the laboratory. III. Find suspect agent is every case of disease of interest but not in healthy hosts. IV. Recover and isolate suspect agent from test subject.
III, II, I, IV
West Nile Virus is an arbovirus that can be transmitted by birds because they develop viremia when infected. In contrast, infected humans cannot spread the disease because they do not develop viremia. Why is viremia associated with the ability to transmit the disease? Direct contact with blood is required for infection. If there are no viral particles in the blood, then infection can't occur using this mechanism. Because white blood cells are found in the blood, any virus in the blood would be attacked by the immune system. With no viral particles available for the immune system to attack, the virus cannot be spread. The virus is only found within red blood cells if there is no viremia, so it cannot be spread by mosquitoes that do not consume those cells. If there are no (or only very few) viral particles in the blood, then they are not picked up by vectors feeding on the blood in sufficient amounts to cause infection.
If there are no (or only very few) viral particles in the blood, then they are not picked up by vectors feeding on the blood in sufficient amounts to cause infection.
Arrange the following statements in the order that best represents the chronological order of events in generating an anaphylactic reaction.
IgE molecules bind to mast cells and basophils. Antigen molecules cross-link adjacent IgE molecules. Degranulation occurs. Chemical mediators such as histamine are released. Capillary permeability and smooth muscle contractions increase. Neutrophils and eosinophils move to the site.
Match the persons to their contribution in the field of microbiology.
Ignaz Semmelweis A. introduced handwashing to minimize infection in maternity wards Joseph Lister C. advanced the idea of antisepsis in health care settings with the use of phenol Florence Nightingale D. the founder of modern nursing Edward Jenner B. began the field of immunology
Antibiotic resistance is a major concern as microbes can rapidly develop resistance when antibiotics are not used appropriately. Which of the following examples best describes how this occurs? Microbes respond to the presence of antibiotics by deliberately developing resistance mechanisms. Exposure to too much of an antibiotic causes resistance. Antibiotics are mutagenic. They cause mutations, like other mutagenic chemicals. In any population of microbes, some individuals may have resistance genes. When exposed to an antibiotic, there is selection for the microbes that have these genes.
In any population of microbes, some individuals may have resistance genes. When exposed to an antibiotic, there is selection for the microbes that have these genes.
Veterinarians and spelunkers (people who explore caves that may have large populations of bats) should be vaccinated against rabies. The rabies vaccine is made by treating the rabies virus with a chemical to render it non-infective. Based on this, how is the rabies vaccine best characterized?
Inactivated
A lysogenic virus...?
Incorporates its nucleic acid with that of the host chromosome
What caused the swelling in the inflamed area?
Increase in permeability of blood vessels that increases the leakage of fluid to the injured area
How would one increase the concentration of a particular polypeptide in a cell?
Increase the level of transcription
From the preliminary analysis, it would appear that individuals who consumed barbecue with Bubba-Qs sauce had the highest attack rate, followed by the dry-rubbed barbecue. Some of the individuals who said they ate the barbecue with the sauce did not become ill. Which one of the following is the most likely explanation for such an occurrence? Not everyone who was questioned may accurately remember which foods they consumed. Individuals who did not become ill are genetically less susceptible to the food poisoning agent. Some individuals may have immunity to the illness because they have been previously exposed. Individuals who became ill may have consumed larger quantities of the food than individuals who did not become ill.
Individuals who became ill may have consumed larger quantities of the food than individuals who did not become ill.
Which operons are never transcribed unless activated?
Inducible operons
What is germ theory of disease?
Infectious diseases are caused by microorganisms.
Which of these is NOT a difference between eukaryotic and bacterial gene expression?
Initiation of translation in bacteria occurs when the ribosomal subunit binds to the 5' guanine cap, while in eukaryotes it binds to a specific nucleotide sequence.
Bt crops are engineered in the lab to produce Bt toxins due to the presence of a bacterial gene from B. thuringiensis. Why is it advantageous for the plants to produce the Bt toxin?
Insects that normally destroy non-toxin-producing crops will be killed when they eat plants that do produce the toxin
Bt crops are engineered in the lab to produce Bt toxins due to the presence of a bacterial gene from B. thuringiensis. Why is it advantageous for the plants to produce the Bt toxin? The Bt toxin will protect the plant from pathogenic bacteria. The plant will release chemicals that will repel all nearby insects. People who eat the food produced by a Bt crop will be resistant to bacterial infections. Insects that normally destroy non-toxin-producing crops will be killed when they eat plants that do produce the toxin.
Insects that normally destroy non-toxin-producing crops will be killed when they eat plants that do produce the toxin.
Which of the following enzymes is/are involved with the integration of viral DNA into the host chromosome?
Integrase
A researcher inserted DNA fragments from an organism into expression vector plasmids and introduced the modified plasmids into bacterial cells. Which of the following methods would be an effective means of identifying which clones contain a specific gene of interest?
Isolate clones that still have the vector's genetic marker.
Why is vasodilation important to tissue repair?
It allows for an increased delivery of oxygen, nutrients, and phagocytes to the site of damage
What is the advantage to spirochetes of the corkscrew movement provided by axial filaments?
It allows the cells to move more easily through viscous human tissues and fluids, such as mucus.
Why is polymyxin only used on the skin?
It can also damage living human cell membranes, but the drug is safely used on the skin, where the outer layers of cells are dead.
Why is polymyxin only used on the skin? It can also damage living human cell membranes, but the drug is safely used on the skin, where the outer layers of cells are dead. It has no effect on bacteria that live in the GI tract. It is sensitive to degradation by acid, making oral delivery unsuitable. It can disrupt the metabolic pathways found in humans.
It can also damage living human cell membranes, but the drug is safely used on the skin, where the outer layers of cells are dead.
Why would a recombinant DNA molecule be inserted into a host cell?
It can be copied, transcribed, and translated into a desired protein
Why would a recombinant DNA molecule be inserted into a host cell?
It can be copied, transcribed, and translated into a desired protein.
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.
How does the protozoan Trypanosoma evade detection by the immune system? It produces a capsule which is composed of polysaccharides similar to those found in the host. It can change the surface antigens frequently, preventing the immune system from tracking it. It prevents phagosome-lysosome fusion. It can resist oxidation inside macrophages.
It can change the surface antigens frequently, preventing the immune system from tracking it.
Why is DNA polymerase from Thermus aquaticus ideal for PCR?
It can withstand the high temperatures associated with PCR
Why does immersion oil improve resolution?
It increases the angle of refraction of the light.
Which of the following are true about the chromosome of bacteria?
It is circular in shape. It is double stranded. It is composed of DNA and non-histone proteins.
How is a secondary immune response different from a primary immune response?
It is faster and more effective.
What is meant by light rays being divergent?
It is spreading out
Which of the following statements are true about the synthesis of the lagging strand of DNA?
It is synthesized in the direction away from the replication fork. It is synthesized in short pieces.
How does the bobtail squid select only Aliiovibrio fischeri for colonization of the light organ? It produces nitric oxide in the mucus only. It produces nitric oxide in the mucus and light organ. It produces mucus that aggregates gram-negative bacteria. Aliiovibrio fischeri is present in very high numbers in marine environments, so it isn't necessary to select for it.
It produces nitric oxide in the mucus and light organ.
What is the function of the conjugation pilus?
It pulls the F+ and F- cells together
A strain of Streptococcus pneumoniae is no longer able to synthesize its capsular polysaccharide. What is a likely outcome?
It will be readily phagocytized upon entering the host
A strain of Neisseria gonorrhoeae has been genetically altered and can no longer produce fimbriae. What is a likely outcome?
It will be unable to adhere to host tissue and establish infection
Immunoassays are techniques that use immunology to determine the presence of antigens, antibodies, or both. In one type of enzyme-linked immunoassay test, antibodies are attached to a matrix (such as the bottom of a microtiter plate). Next, the sample to be tested (such as patient serum) is added. An antibody-enzyme complex is then added. Finally, the enzyme substrate is added. The enzyme must catalyze a reaction that is visible (such as a color change), meaning that it is possible to see if the antibodies were present by seeing if there is a color change. The development of the colored product is proportional to the concentration of antibody. What would this sort of test be useful for? It would be useful for detecting whether a patient had antibodies for a particular pathogen. The second antibody (attached to the enzyme) is able to bind because it is specific for the antigen. It would be useful for detecting a virus in a patient's blood, as the antibody on the matrix would bind to the virus. The second antibody (attached to the enzyme) is able to bind because it is specific for the first antibody. It would be useful for detecting whether a patient had antibodies for a particular antigen. The second antibody (attached to the enzyme) is not necessary as the enzyme can react directly with the antigen if the antigen is present. It would be useful for detecting a virus in a patient's blood, as the antibody on the matrix would bind to the virus. The second antibody (attached to the enzyme) is able to bind because it is specific for the antigen.
It would be useful for detecting a virus in a patient's blood, as the antibody on the matrix would bind to the virus. The second antibody (attached to the enzyme) is able to bind because it is specific for the antigen.
Ultraviolet light penetrates (more/less) effectively than gamma rays.
LESS
Lactose-fermenting bacteria turn eosin-methylene blue medium from colorless to black or red. What causes this change? Lactose fermentation allows pyruvate to build up. This excess of pyruvate causes the color change. Lactose fermentation generates lactic acid. Lactic acid lowers the pH of the medium, causing the medium to change colors. Lactose fermentation generates lactate, making the medium more alkaline and causing the color change. Lactose fermentation generates alcohol. The alcohol reacts with chemicals in the medium to cause the color change.
Lactose fermentation generates lactic acid. Lactic acid lowers the pH of the medium, causing the medium to change colors.
Match the phases of bacterial growth to their descriptions.
Lag phase C. enzymes required for growth are synthesized Log phase B. cells divide at a constant rate Stationary phase D. number of cells that are multiplying equals the number of cells that are dying Death phase F. number of cells that are dying is greater than the number of cells that are multiplying Phase of prolonged decline E. survivors have adapted to tolerate worsened conditions
Which of the following are terms associated with Okazaki fragments?
Lagging strand, DNA ligase, and discontinuous
Which of the following would be a reason to use bacteria or yeast to synthesize human proteins through genetic engineering? There is a risk of accidentally transferring pathogens. The protein produced by microbes works more efficiently than the original protein. This approach is usually more expensive than traditional methods. Large quantities of the protein can be made easily.
Large quantities of the protein can be made easily.
The small size of a genetic vector is an advantage because __________.
Larger molecules would be too fragile to manipulate in the lab
The amateur scientist (Koch/Leeuwenhoek/Pasteur) made his own microscopes and first reported the existence of microbes.
Leeuwenhoek
Water supplies are treated with chlorine to kill pathogens. Chlorine reacts well with many other chemicals and bacterial cells because it is a strong oxidant. However, Legionella pneumophila can sometimes evade killing by residual chlorine. How does it do this? Legionella can detoxify chlorine by metabolizing it. Legionella tends to be found in warm waters and in aerosols, both situations in which the chlorine readily evaporates and, thus, is in lower concentration in the water. Legionella tends to form biofilms and infect other microbial cells as intracellular pathogens. Legionella produces cations that bind up the negative chloride ions, thus inactivating them.
Legionella tends to form biofilms and infect other microbial cells as intracellular pathogens.
Antifungal medications are often used topically. Why is this the case? Like human cells, fungal cells are prokaryotic. To develop systemic fungal medications requires finding specific characteristics of fungal cells that can be targeted, such as the ergosterol in fungal cell membranes. Like human cells, fungal cells are eukaryotic. To develop systemic fungal medications requires finding specific characteristics of fungal cells that can be targeted, such as the ergosterol in fungal cell membranes. It is not possible for fungi to cause systemic infections, so only topical treatments are needed. Fungi force cells to help them reproduce, making it difficult to target them without harming the host.
Like human cells, fungal cells are eukaryotic. To develop systemic fungal medications requires finding specific characteristics of fungal cells that can be targeted, such as the ergosterol in fungal cell membranes.
Who performed experiment that disproved spontaneous generation theory?
Louis Pasteur Francesco Redi Lazzaro Spallanzani
Based on the animation, T cells recognized the antigen displayed by what protein of the B cell?
MHC
T cells recognize epitopes only when they are bound to __________.
MHC
Which proteins on the antigen-presenting cell are recognized by the helper T-cell?
MHC proteins
The abbreviation (MIC/MID/MBC) stands for the smallest amount of a drug that will inhibit the growth and reproduction of a pathogen.
MIC
Which of the cells listed below can present antigens on Class II MHC proteins?
Macrophages
During the initiation step of translation, the fMet charged tRNA assembles in which site of the ribosome?
P site
If high amounts of sulfanilamide are in the presence of an enzyme whose substrate is PABA, what outcome is expected?
PABA will not be catalyzed.
Microbial molecules detected by phagocytes are called
PAMPs.
A clinical lab was not able to isolate any pathogenic bacteria from a patient suffering from a high fever and elevated white blood cell count. The physician suspects a viral infection may be to blame. What detection assay may the lab want to try next? PCR followed by a nucleic acid hybridization technique to detect viral DNA or RNA an agglutination test immunofluorescence an immunoblot (Western blot) assay
PCR followed by a nucleic acid hybridization technique to detect viral DNA or RNA
Who made an experiment that finally disproved the theory of spontaneous generation?
Pasteur
_______________ is a process used to destroy pathogens in food and drinks. It must be done at a lower temperature than other methods so that _______________.
Pasteurization; the taste of the food or drink will not be altered
Match the terms with its description.
Pathogenicity E. ability of a microorganism to cause disease Virulence C. degree of pathogenicity Pathogen D. the microbe that cause the disease Normal microbiota B. microbes that live on and in our body without causing apparent harm
Which antibiotic is overcome by beta-lactamases?
Penicillin
Which antibiotic is overcome by beta-lactamases? Tetracycline Sulfonamide Penicillin Tetracycline, Penicillin, and Sulfonamide are all affected by beta-lactamase.
Penicillin
Why would an efflux pump for penicillin located on a bacterial cell membrane not be effective at providing resistance to the drug?
Penicillin disrupts the cell wall, which is located outside of the cell membrane.
Why would an efflux pump for penicillin located on a bacterial cell membrane not be effective at providing resistance to the drug? The efflux pumps would not stop penicillin from blocking metabolic pathways. There are fewer efflux pumps on the cell membrane. The cell membrane is the target of penicillin. Penicillin disrupts the cell wall, which is located outside of the cell membrane.
Penicillin disrupts the cell wall, which is located outside of the cell membrane.
Compare the thickness of peptidoglycan of Gram-positives from Gram-negatives.
Peptidoglycan of Gram-positives is thicker than peptidoglycan of Gram-negatives.
If the upper strand of the DNA molecule below acts as template to make mRNA, what is the sequence of amino acids that will be translated from the mRNA? 3' AAG-CAA-GAC-GAA 5' 5' TTC-GTT -CTG-CTT 3'
Phe-Ala -Leu-Leu
What process is used to "amplify" DNA, making large numbers of copies from a small sample?
Polymerase chain reaction
Which of the following processes is used to "amplify" DNA, making large numbers of copies from a small sample?
Polymerase chain reaction
Which technique or tool of recombinant DNA technology makes many copies of a DNA molecule? Electrophoresis Reverse transcriptase (RT) Restriction enzymes Polymerase chain reaction (PCR)
Polymerase chain reaction (PCR)
Which of the following terms refers to a bacterium moving towards a light source?
Positive phototaxis
Which of the following would not move freely across the cytoplasmic membrane?
Positively charged hydrogen ions
A researcher inserted DNA fragments from an organism into expression vector plasmids and introduced the modified plasmids into bacterial cells. Which of the following methods would be an effective means of identifying which clones contain a specific gene of interest?
Prepare and analyze restriction fragments of the plasmids.
One way to test if someone has immunity to a particular pathogen is to measure the antibody titer. What does it mean if someone has a positive antibody titer? Previous exposure to the pathogen (or through a vaccination) has caused B cells to produce memory B cells. When re-exposed to the pathogen, they rapidly produce antibodies against the antigen (resulting in a positive antibody titer). They must not have been exposed to the pathogen previously, meaning that they were able to rapidly produce antibodies. They must not have been exposed to the pathogen previously, meaning that they were not able to rapidly produce antibodies. Previous exposure to the pathogen has caused T cells to attack the pathogen, leading to a more rapid response by T cells upon repeat exposure.
Previous exposure to the pathogen (or through a vaccination) has caused B cells to produce memory B cells. When re-exposed to the pathogen, they rapidly produce antibodies against the antigen (resulting in a positive antibody titer).
Sort these characteristics based on whether they are best associated with a primary response or a secondary response.
Primary: Promoted by vaccination of an infant Lag in antibody production IgM is the only antibody produced early in the response Promoted by exposure to pathogen in an unvaccinated individual IgG is produced later in the response secondary: Extremely rapid antibody production Occurs after the second exposure to the pathogen IgG is produced early in the response Occurs upon exposure to pathogen after vaccination
Compare and contrast three metabolic pathways by choosing whether the statement applies to anaerobic respiration. Check all that apply.
Process includes glycolysis The coenzyme NAD+ plays an important role in the pathway. Much or most of the ATP produced is produced by oxidative phosphorylation. Can generate ATP in the absence of O2. Between 2 and 38 ATP are produced per molecule of glucose input. Process involves electron transport and chemiosmosis Process involves the Krebs cycle
In examining a MRSA strain, researchers find that degraded penicillin is found in the culture medium. What is the most likely mechanism of resistance? View Available Hint(s)
Production of a beta-lactamase
What are the functions of glycocalyx?
Protects the cells from dessication. Protects the cells from the body's defensive cells. Attachment cells to each other and to the environment.
Which of the following microbes has been genetically engineered to contain a protein that helps protect crops from freezing? a. Escherichia coli b. Deinococcus radiodurans c. Salmonella d. Pseudomonas e. Bacillus thuringiensis
Pseudomonas
Which of the following microbes has been genetically engineered to contain a protein that helps protect crops from freezing?
Psudomonas
What is the hallmark of all horizontal gene transfers?
Transfer of DNA between organisms of the same generation
Match the types of microorganism based on temperature to their characteristics.
Psychrotrophs C. cause spoilage of refrigerated foods Mesophiles E. grow in the human body Thermophiles A. grow in hot springs and compost heaps Hyperthermophiles B. can grow in the wall of hydrothermal vents
Match the structures in bacteria to their functions.
QuestionCorrect Match Flagella B. for movement Fimbriae D. for attachment Inclusions A. for storage of substances Plasma membrane C. ATP production Endospore E. for survival
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If a particular bacterial species is resistant to beta-lactam antibiotics, which of the following might you expect to find inside the bacterial cells?
R plasmids
Which of the cells listed below cannot present antigens on Class I MHC proteins?
RBC
Retrovirus
RNA virus that is duplicated in a host cell using the reverse transcriptase enzyme to produce DNA from its RNA genome. The DNA is then incorporated into the host's genome by an integrase enzyme
Which of the following statements regarding redox reactions is true?
Redox reactions involve an oxidation reaction coupled with a reduction reaction.
Sally decides to go through the desensitization program recommended by her doctor. What is the overall purpose/goal of this process?
Repeated exposure to wasp venom antigen will increase the amount of IgG produced by Sally's immune system.
Which step of binary fission is the reason for genetically identical daughter cells?
Replication of the bacterial chromosome
Which operons are always transcribed unless deactivated?
Repressible operons
How might efflux pumps increase antibiotic resistance in bacteria?
Resistant bacteria can have more efflux pumps, and can have less specific efflux pumps
How might efflux pumps increase antibiotic resistance in bacteria? Resistant bacteria may have a greater number of efflux pumps on their cell surfaces. Some bacteria can decrease the specificity of their efflux pumps, increasing the number of different antibiotics the pumps can eliminate. Some bacteria can change the chemical structure of the antibiotic. Efflux pumps can never be modified to increase antibiotic resistance. Resistant bacteria can have more efflux pumps, and can have less specific efflux pumps.
Resistant bacteria can have more efflux pumps, and can have less specific efflux pumps.
What is the correct order of the construction of a recombinant DNA molecule?
Restriction enzymes cut gene of interest and plasmid DNA Ligation of desired gene to plasmid DNA Introduction of the plasmid into bacteria Growth of cells on an antibiotic-containing medium
Viral Enzymes Needed By Retroviruses
Retroviruses are RNA viruses that contain the enzyme reverse transcriptase. Reverse transcriptase can convert RNA into DNA, which can then be integrated into the host cell's chromosome.
The basal body is comprised of which structural component(s) of flagella?
Rod and Rings
Which of the following statements is true of selective toxicity?
Selective toxicity takes advantage of structural and/or metabolic differences between host and pathogen.
Which of the following is an application that uses PCR?
Sequencing a gene, diagnosing a disease, and providing enough DNA for cloning into another organism
Which of the following is an application that uses PCR? Sequencing a gene Diagnosing a disease Sequencing a gene, diagnosing a disease, and providing enough DNA for cloning into another organism Providing enough DNA for cloning into another organism
Sequencing a gene, diagnosing a disease, and providing enough DNA for cloning into another organism
A common mechanism for antibiotic resistance is alteration of the molecule targeted by the antibiotic. Very small changes in the structure to extensive alterations may produce a gene product on which the antibiotic has limited effect. Match the type of point mutation with the type of damage it is most likely to produce.
Silent: No change in gene product. Frameshift: Extensive change in gene product structure and function. Nonsense: Premature termination of gene product with probable loss of function. Missense: Small change in gene product which may or may not alter function.
Differentiate skin from mucus membrane.
Some cells in the skin are dead while all cells in the mucus membrane are alive. Skin is dry while mucus membrane is moist.
Which of the following best describes the primary role of microorganisms in food production? Microbes are pathogens that can contaminate foods and make people sick. Outbreaks of E. coli and Salmonella are examples. Microbes are found in food that has spoiled. The microbes or the products they produced are what spoils the food. Spoiled milk is an example. Microbes are found in food that requires their metabolic products for flavoring. The use of molds to flavor cheese is an example. Some microbes are responsible for food spoilage, whereas others are used to increase the flavoring of the food or to produce the food product itself.
Some microbes are responsible for food spoilage, whereas others are used to increase the flavoring of the food or to produce the food product itself.
The technique called (northern/Southern/western) blotting is useful for using probes to identify specific DNA fragments that have been separated by electrophoresis.
Southern
Which of the following methods uses DNA probes?
Southern Blot
Which of the following procedures might be used to detect the presence of genetic sequences of a virus in a patient's blood?
Southern blotting
Which of the following procedures might be used to detect the presence of genetic sequences of a virus in a sample? a. Southern blotting or PCR b. genome mapping c. creation of a gene library d. Southern blotting e. PCR
Southern blotting or PCR
Which of the following virulence factors would be found in Staphylococcus aureus?
Staphylokinase
What are the "sticky ends" produced by some restriction enzymes? a. Sticky ends are short single-strand ends of DNA able to hydrogen bond with complementary strands. b. Sticky ends are able to hydrogen bond with complementary strands. c. Sticky ends are DNA strands able to form phosphate bonds with free DNA ends. d. Sticky ends are DNA strands with an extra hydroxyl group on the end. e. Sticky ends are short single-strand ends of a DNA molecule.
Sticky ends are short single-strand ends of DNA able to hydrogen bond with complementary strands.
Which of the following microorganisms use M protein to avoid destruction of a phagocyte?
Streptococcus pyogenes
Native peoples often experience an increase in the incidence of dental caries after they are introduced to imported processed foods. This finding could be explained by the fact that __________. Sucrose and other purified sugars cause pitting of the tooth surfaces. Sucrose is required for the production of adhesive dextran by Streptococcus mutans. Lactobacilli require sucrose in order to form biofilms on tooth surfaces. Only purified sucrose and fructose can be fermented or produce acids in the oral cavity.
Sucrose is required for the production of adhesive dextran by Streptococcus mutans.
__________ are used in the detection of DNA by FISH.
Synthetic DNAs and fluorescent tags
Which of the following is true regarding systemic anaphylactic reactions?
Systemic reactions are commonly associated with injected antigens. A systemic reaction can be fatal in only a few minutes. Systemic reactions can result in a dramatic decrease in blood pressure.
In the thymus, T cells randomly generate different __________ with a particular shape.
T cell receptors
Which of the following cells produced gamma interferons?
T lymphocytes
Under ideal conditions, the number of DNA molecules produced during PCR increases exponentially.
TRUE
Another thermophile, Thermus aquaticus, was isolated from a hot spring in Yellowstone National Park. It is the source of the enzyme Taq polymerase, which is used in the molecular technique called polymerase chain reaction (PCR). PCR is used to amplify sequences of DNA. What extremophile characteristic of this enzyme makes it an essential component in a PCR reaction? Taq polymerase is stable under acidic or alkaline conditions. Taq polymerase is stable under extremely cold temperatures. Taq polymerase is heat-stable and can withstand high temperatures. Taq polymerase is stable in solutions that are extremely high in salt.
Taq polymerase is heat-stable and can withstand high temperatures.
Which of the following best explains how scientists are able to introduce the bacterial gene for Bt toxin into the cotton plant genome?
The Bt toxin gene is isolated and inserted into a Ti plasmid from Agrobacterium tumefaciens. The engineered Ti plasmid is taken up by a bacterium that infects the cotton plant
Which of the following best explains how scientists are able to introduce the bacterial gene for Bt toxin into the cotton plant genome? The bacterial gene for Bt toxin is isolated, and the DNA is put into tiny bullets (like BB's) that are "shot" into the cotton plant using a gene gun. The Bt toxin gene is isolated and inserted into a Ti plasmid from Agrobacterium tumefaciens. The engineered Ti plasmid is taken up by a bacterium that infects the cotton plant. A virus is engineered to contain the Bt toxin gene. This virus is then used to infect the plant and pass on the gene. The Bt toxin gene is added to water that is sprayed on the cotton plants. The gene is taken up through the roots of the plant.
The Bt toxin gene is isolated and inserted into a Ti plasmid from Agrobacterium tumefaciens. The engineered Ti plasmid is taken up by a bacterium that infects the cotton plant.
A key feature of cellular respiration is the removal of electrons from fuel molecules (oxidation) and the ultimate acceptance of these electrons by a low-energy electron acceptor. The process involves the use of electron carriers, NAD+ and FAD, which play crucial roles in multiple steps of the metabolic pathways. The overall equation for cell respiration is shown below. Why do NAD+ and FAD NOT appear in the overall equation? C6H12O6+6O2+38ADP+38Pi→6CO2+6H2O+38ATP
The NAD+ and FAD are initially reduced then oxidized to their original state, so they do not appear in the net equation
A researcher mistakenly uses a heat sensitive version of DNA polymerase in a PCR. Which of the following will occur?
The PCR will stop after one cycle
A researcher mistakenly uses a heat-sensitive version of DNA polymerase in a polymerase chain reaction (PCR). Which of the following will occur?
The PCR will stop after one cycle.
What most likely explains the recovery of live S strain cells from a mouse injected with heat-killed S strain mixed with live R strain cells?
The R strain picked up the S strain DNA, enabling it to produce a capsule.
What will happen if an animal raised in an axenic environment is exposed to a pathogenic microbe later in life?
The animal will exhibit a very poor immune response to the pathogen.
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.
What it means if an antibody molecule is described as bivalent?
The antibody has two antigenic sites.
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 the ribosome know if the entering charged tRNA is correct?
The anticodon on the tRNA base pairs to the codon on the mRNA.
In the previous question, you learned that adding starter bacterial cultures is a necessary part of the cheese-making process. In the production of red wine, the starter cultures are made up of yeasts rather than bacteria. In both cases, the microbes are used for their fermentation capabilities and the production of the final product. Which of the following choices best explains how the fermentation processes in these two organisms, although similar in nature, produce two very different products? The bacteria and yeast produce sugars as a metabolic by-product, giving the cheese and wine a sweet flavor and characteristic aroma. The bacteria produce alcohols as a metabolic by-product that give the cheese its characteristic flavor and aroma, whereas the yeasts produce acids that give the wine its characteristic flavor and aroma. The bacteria produce acids as a metabolic by-product that give the cheese its characteristic flavor and aroma, whereas the yeasts produce alcohols that give the wine its characteristic flavor and aroma. The bacteria and yeasts produce fats as a metabolic by-product that give the cheese and wine their characteristic flavor and aroma.
The bacteria produce acids as a metabolic by-product that give the cheese its characteristic flavor and aroma, whereas the yeasts produce alcohols that give the wine its characteristic flavor and aroma.
What is meant when a bacterium is said to become "resistant" to an antibiotic? The antibiotic kills or inhibits the bacterium. The antibiotic is metabolized by the bacterium, providing more energy for growth of the cell. The bacterium is neither killed nor inhibited by the antibiotic. The antibiotic mutates in a way that benefits the bacterium.
The bacterium is neither killed nor inhibited by the antibiotic.
The IgG molecules that are produced during desensitization function as blocking antibodies. These antibodies are extremely effective in providing protection from a hypersensitivity reaction. Why are blocking IgG antibodies so effective at protecting Sally from another anaphylactic response to wasp venom?
The blocking IgG antibodies "outnumber" the IgE antibodies and bind to wasp venom before the IgE antibodies can bind.
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.
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. Capsules allow the bacteria to stick together, creating a larger mass that is too big for immune cells to engulf. The capsule makes the bacterium too sticky to be phagocytosed by the immune cells. Capsules have the ability to destroy antibodies secreted 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.
In a repressible operon, which of the following must occur to enable gene expression?
The corepressor must be absent.
If the patient were to get a subsequent urinary tract infection, what should the doctor prescribe knowing that she is susceptible to thrush?
The doctor should prescribe an antibiotic specific for the bacterial species causing the urinary infection.
Which organelle assists directly with the presentation of MHC-I antigens?
The endoplasmic reticulum
The P. multocida that are growing within Sam's abscess are breaking glucose down via glycolysis in order to obtain energy. This process occurs via a series of enzymatic reactions. During a chemical reaction, an enzyme functions as a biological catalyst and lowers the activation energy. How does an enzyme lower the activation energy of a reaction?
The enzyme increases the effectiveness of reactant collisions thereby increasing the number of reactant molecules that reach activation energy.
Examine the figure above depicting the preparatory step and the Krebs cycle, and identify statements that correctly describe these processes. Select all statements that correctly describe the preparatory step and the Krebs cycle.
The equivalent of one ATP is made for each turn of the Krebs cycle. Carbons from pyruvic acid end up as CO2. It takes two "turns" of the Krebs cycle to process the pyruvic acid molecules resulting from the glycolysis of one glucose molecule. The oxaloacetic acid that accepts the acetyl group is regenerated, enabling the cyclic nature of this process. There are five oxidation-reduction reactions depicted. The potential energy in the pyruvate is transferred to coenzymes NAD+ and FAD.
Disease research and epidemiology bring together many different facets to help us better understand disease pathology and spread. Which of the following statements are true? Select all that apply. The interactions that occur between a microbe and host influence the evolution of both. Some pathogens are able to cause disease within a host without penetrating the body. Intoxications result from a bacterial infection in which a large amount of bacterial toxin is produced. The ID50 value refers to the number of microbes needed to cause half of an infected population to die. Bacterial exotoxins can be altered to create toxoids, which can be used to produce protective immunity in a host. The terms pathogenicity and virulence can be used interchangeably to describe the severity of an infection.
The interactions that occur between a microbe and host influence the evolution of both. Some pathogens are able to cause disease within a host without penetrating the body. Bacterial exotoxins can be altered to create toxoids, which can be used to produce protective immunity in a host.
The major virulence factor produced by C. diphtheriae is diphtheria toxin. The production of diphtheria toxin during infection is controlled by a repressor, DtxR. The activity of DtxR is regulated by iron, which acts as a corepressor. During an infection, the levels of iron available in the tissues for use by C. diphtheriae are low. What effect will the decreased iron availability have on the production of diphtheria toxin
The lack of corepressor binding to DtxR will lead to a loss of repression and an increase in the production of toxin.
One of two men may be the father of a child. This figure shows the results of a DNA fingerprint analysis to determine paternity. M is the mother, C is the child, A and B are the two men. What is the best interpretation of these results?
The man identified as B is probably the father.
Two men may be the father of a child. the figure shows the results of a DNA fingerprint analysis to determine paternity. M is the mother, C is the child, A and B are the two men. What is the best interpretation of these results?
The man identified as B is probably the father.
All restriction sites are palindromic. What does this mean?
The nucleotide sequences at the restriction sites are the same when read forward or backward.
All restriction sites are palindromic. What does this mean?
The nucleotide sequences at the restriction sites are the same when read forward or backward. Submit
According to the animation, where on the DNA strand does a repressor bind?
The operator
With which genetic region does the repressor protein interact?
The operator region
One of the environmental changes that P. multocida encounters during infection is the limitation of nutrients and oxygen. One of the changes that P. multocida (a facultative anaerobe) makes in this environment is to switch to anaerobic metabolism. Predict which of the following is most likely to occur as a result of the switch from aerobic to anaerobic metabolism.
The organisms will grow more slowly because they will produce less ATP compared to aerobic metabolism.
What would happen if the septum did not form during binary fission?
The parent cell would now have two copies of the chromosome.
Lysogenic Phage
The phage initially become incorporated into an infected cell's chromosome and is called a prophage. Later the prophage can excise itself from the chromosome and become enclosed in viral particles as they are produced in the infected cell. The infected bacterium then lyses and releases the viral particles- some containing viral DNA and some containing diner bacterial DNA.
Which of the following best characterizes clonal selection?
The production of identical B cells producing the same antibody
According to the animation, to what genetic element does the RNA polymerase bind?
The promoter
What is the initial target of RNA polymerase
The promoter
What is the initial target of RNA polymerase?
The promoter
How can specialized transduction contribute to the transfer of antibiotic resistance genes in a bacterial population?
The prophage takes an antibiotic resistance gene with it and is packaged with the newly synthesized viral DNA.
Which of the following is NOT a reason why human proteins can be synthesized in bacteria or yeast through genetic engineering?
The protein produced by microbes works better than the original protein
Which of the following is not a reason why human proteins can be synthesized in bacteria or yeast through genetic engineering?
The protein produced by microbes works better than the original protein
Which of the following is NOT a reason why human proteins can be synthesized in bacteria or yeast through genetic engineering?
The protein produced by microbes works better than the original protein.
If a human is bitten by an animal that has rabies, then it is recommended that the human receive immune globin (human rabies antibodies) and a rabies vaccination (with inactive virus) as well. Which of the following is the best (and most specific) explanation for why both are recommended in this case? Hints The rabies vaccination is relatively new and ineffective, so it is important to give the immune globin as well to make certain that the viruses cannot cause disease. Because rabies is such a serious illness, using antibodies and a vaccine provides the strongest possible immediate protection. Both antibodies and the vaccine provide a rapid immediate response to prevent illness from developing. Using both is needed because an individual who has received this type of bite is more likely than someone else to receive another bite. While the immune globin is sufficient to prevent rabies infection, the vaccination helps to prevent the individual from the risk of a future bite. The rabies antibodies provide a rapid response but short-lived response while the vaccination provides slower but longer-lasting protection.
The rabies antibodies provide a rapid response but short-lived response while the vaccination provides slower but longer-lasting protection.
Why are receptors on the cell surface necessary for bacterial movement?
The receptors sense the stimulus and send signals to the flagella.
As you have seen, IgE is responsible for allergy, IgM is produced early in a primary response, and IgG is produced early in a secondary response. Based on the diagram provided, which part of an antibody molecule determines differences between an anti-pollen IgE, IgG and IgM?
The stem (Fc)
What information is conveyed by the name of a restriction enzyme?
The strain of the bacterium in which it was discovered, the species of the bacterium in which it was discovered, and the order of its discovery compared to other restriction enzymes from that bacterium
What is a phagolysosome?
The structure that results from the fusion of a phagosome and a lysosome.
Why is the DNA synthesis of the lagging strand considered discontinuous?
The synthesis is moving in the opposite direction from the replication fork.
When a child begins to get its first teeth, what happens to the microbiota in the oral cavity? The teeth are rapidly colonized by anaerobes, in particular Streptococcus, that are specifically adapted to growth in biofilms in the gingival crevices. The teeth are rapidly colonized by obligate anaerobes, in particular Fusobacterium, that are specifically adapted to growth in biofilms on the surfaces of the teeth. The teeth are rapidly colonized by aerobes, in particular Streptococcus, that are specifically adapted to growth in biofilms on the surfaces of the teeth. The teeth are rapidly colonized by anaerobes, in particular Streptococcus, that are specifically adapted to growth in biofilms on the surfaces of the teeth.
The teeth are rapidly colonized by anaerobes, in particular Streptococcus, that are specifically adapted to growth in biofilms on the surfaces of the teeth.
What would be the effect of the transfer of glyphosate resistance from a transgenic crop plant to a weed plant?
The weed plant would be unable to be killed by particular herbicides
What would be the effect of the transfer of glyphosate resistance from a transgenic crop plant to a weed plant?
The weed plant would be unable to be killed by particular herbicides.
The yellow fever virus replicates in lymph nodes and in other immune system cells. How does it arrive in lymph nodes? It is injected there by the mosquitoes that carry the disease. The yellow fever virus is phagocytosed by white blood cells, and then travels through the lymph vessels. Lymph nodes contain white blood cells and filter lymph as it moves through the lymph vessels. White blood cells with yellow fever virus can become established there. Some viruses, like the yellow fever virus, can replicate inside of white blood cells like those in lymph nodes. The virus is carried to the lymph nodes by the blood stream. It is attracted to the lymph nodes by chemoattractants.
The yellow fever virus is phagocytosed by white blood cells, and then travels through the lymph vessels. Lymph nodes contain white blood cells and filter lymph as it moves through the lymph vessels. White blood cells with yellow fever virus can become established there. Some viruses, like the yellow fever virus, can replicate inside of white blood cells like those in lymph nodes.
How is Streptococcus pneumoniae able to avoid destruction by a phagocyte?
Their capsules make them "slippery" to phagocytes.
Collectively, metagenomic studies of the human microbiome have shown ALL BUT one of the following statements are true. There is no general pattern of similarity in the microbiomes of humans; they are unpredictable. Microbial diversity in the human microbiome is so great that no one microbial species is present in the greatest abundance in all individuals. Similarities in microbial diversity between individuals are more evident at higher bacterial taxonomic levels (such as phyla). Certain microbial genes appear to be linked to certain human body sites.
There is no general pattern of similarity in the microbiomes of humans; they are unpredictable.
Why are invasive procedures likely to increase the risk of nosocomial infections? Invasive procedures must use antibiotics. These procedures allow microbes from the skin to enter the bloodstream of the patient. Invasive procedures require long term hospital stays, thereby increasing the number of visitors seen by the patient. These procedures are carried out by health care workers, who carry resistant microbes.
These procedures allow microbes from the skin to enter the bloodstream of the patient.
What is the hallmark of a conjugated vaccine?
These vaccines contain weakly antigenic elements plus a more potent antigenic protein.
Which of the following are functions of lectins?
They act as opsonins for phagocytosis, they attach to carbohydrates on some bacterial and viral surfaces, and they activate C2 and C4.
What direct effect do histamines and leukotrienes have on capillaries?
They allow capillary walls to open and become leaky.
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.
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. They can compare the DNA sequences from the foreign cells to host DNA. They detect foreign, unfamiliar chemical substances released by the invading cells.
They are able to detect structures on the surfaces of foreign cells that are not found in the host.
Considering that they require an oxygen-free environment, how do obligate anaerobes survive in the human body? They are able to use enzymes to convert reactive oxygen species to harmless molecules. They live inside of organelles, such as peroxisomes. They are able to survive in places where aerobic organisms quickly use the available oxygen. They can also survive in areas with impaired blood flow (reducing oxygen availability). Obligate anaerobes are unable to survive in the human body.
They are able to survive in places where aerobic organisms quickly use the available oxygen. They can also survive in areas with impaired blood flow (reducing oxygen availability).
Which are true statements about plasmids?
They are double stranded. They are circular in shape.
Which of the following is NOT a characteristic of Okazaki fragments?
They are longer in eukaryotic cells.
Which are true about subunit vaccines?
They are made up of parts of bacteria or viruses They are acellular. They do not pose a risk for causing the disease. They are safer compared to vaccines made up of inactivated microbes
Which statements are true about antibodies?
They are soluble proteins found in the blood. They are involved in an immune response.
In reference to clonal deletion, what are the clones?
They are the offspring or potential offspring of lymphocytes.
Which of the following is NOT a characteristic of viruses?
They are visible with a light microscope.
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 fibrinolysins enhance a pathogen's virulence? They destroy the molecules that hold cells together. They destroy the fibers that are found at the base of superficial tissues, allowing for deeper penetration by the pathogen. They break down fibrin proteins that are involved in clot formation, allowing the cells to penetrate deep into damaged skin.
They break down fibrin proteins that are involved in clot formation, allowing the cells to penetrate deep into damaged skin.
How do superantigens enable pathogens to hide from the immune system if they actually stimulate the immune system? They cause fever, which destroys the complement proteins. They cause the immune system to destroy IgA antibodies. They cause the immune system to turn on itself. They cause the immune system to produce an exaggerated response, distracting it from the actual pathogen.
They cause the immune system to produce an exaggerated response, distracting it from the actual pathogen.
How do restriction enzymes cut DNA sequences?
They cut DNA at sites, called recognition sites, that have specific nucleotide sequences
How do restriction enzymes cut DNA sequences?
They cut DNA at sites, called recognition sites, that have specific nucleotide sequences.
How do restriction enzymes cut DNA sequences?
They cut DNA at sites, called recognition sites, that have specific nucleotide sequences. Submit
Which is the function of restriction enzymes?
They cut DNA at specific sequences.
What action do restriction enzymes employ?
They cut DNA.
What role do restriction enzymes serve in the prokaryotes that produce them?
They destroy viral DNA.
Why are mycoplasmas resistant to penicillin and other β lactam drugs?
They do not have cell walls.
What makes phospholipid membranes good at keeping some molecules out, and allowing others to freely pass?
They have both hydrophilic and hydrophobic regions.
A researcher wanted to determine the LD50 (lethal dose that kills 50% of the infected hosts) for a newly isolated bacterial pathogen. Mice were inoculated with diluted cultures containing between 101 and 107 cells. After two days, all of the mice had died EXCEPT for the uninoculated controls. Which of the following is the most likely explanation? Mice are not good model animals for this pathogen. The pathogen has become attenuated. This pathogen is highly virulent in mice. The pathogen has a very high LD50.
This pathogen is highly virulent in mice.
What is the purpose of making successive streaks in streak-plate method?
To dilute the cells
Which of the following are goals of recombinant DNA technology?
To eliminate undesirable traits from livestock or crops. To combine genetic material from more than one organism to produce new useful organisms. To be able to remove or correct damaging traits in humans. To create organisms capable of producing useful products.
Some studies have indicated that the ID50 for Vibrio cholerae can be as high as 108 organisms. Which of the following most likely explains the requirement for this relatively high ID50? V. cholerae does not produce enough virulence factors to overcome the host response and cause disease. Because V. cholerae cells are relatively small compared to host cells, thousands of bacteria must infect each cell to cause disease. Because the major virulence factor of V. cholerae is cholera toxin, large numbers of bacteria are required to produce enough toxin to cause disease. To establish infection, V. cholerae must survive the host immune response and the acidic environment of the stomach.
To establish infection, V. cholerae must survive the host immune response and the acidic environment of the stomach.
What is the role of epidemiology? To learn which organisms cause disease. To learn which medicines are effective at killing pathogens. To learn how to treat and prevent various diseases. To learn what diseases can be caused by respiratory pathogens.
To learn how to treat and prevent various diseases
What is a Southern blot used for?
To locate DNA sequences of interest in a collection of DNA fragments
What is the end goal of PCR?
To quickly increase the number of copies of a specific DNA sequence
What is the end goal of PCR? To increase the pool of different DNA sequences To quickly increase the number of copies of a specific DNA sequence To allow cells to make DNA faster, thereby growing faster
To quickly increase the number of copies of a specific DNA sequence
What is the role of the ocular lens?
To recreate the image in the viewer's eye
Which of the following is NOT true about toll-like receptors?
Toll-like receptors are molecules found on the surface of microbes that can initiate immune reactions.
Tom has a genetic disorder in which he does not synthesize class I MHC proteins or functional NK cells. Which of the following statements would be true for Tom?
Tom would not be able to destroy virally-infected cells.
Reheating food to a temperature sufficient to kill bacteria is helpful in making food safer. However, is there a way that one can get food poisoning despite food having been reheated? No, it is not possible to develop food poisoning if all of the bacteria have been killed. Toxins may be heat-stable above temperatures that kill bacteria. Even if only a few bacteria survive, those bacteria may be sufficient to start an infection and produce toxins. Even if the toxins have been denatured, they can return to a functional form after cooling.
Toxins may be heat-stable above temperatures that kill bacteria.
Which of the following is an example of horizontal gene transfer in bacteria?
Transduction, conjugation, and transformation
Please recall what you have learned about microbial metabolism and food processing methods and choose the best method for prevention of food spoilage for the food type below. There is a photo of several plates with different kinds of soup. Packaging into cans and jars and exposure to high heat under pressure (canning). Use of salt or sugar to draw water out of foods (preservatives). Use of more than one food processing type (for example, canning and use of preservatives). Freezing and vacuuming to dry foods (lyophilization). High-heat treatment for a short period of time (pasteurization).
Use of more than one food processing type (for example, canning and use of preservatives)
Along her tour, Julie noticed many types of cheeses that were being aged for texture and taste. In the processing of cheese there are many things that can be done to prevent the introduction of microorganisms. This same concept applies not only to cheese, but to wine, vegetables, and meat products. Based on the food that is being manufactured, various processes like pasteurization, chemical preservation, and radiation can all be used. All of these preservation methods take into consideration characteristics of microorganisms, such as the presence or absence of a cell wall, the role of osmotic pressure, their growth at preferred temperatures, and many other important characteristics. Please recall what you have learned about microbial metabolism and food processing methods and choose the best method for prevention of food spoilage for the food type below. There is a photo of pea pod. Packaging into cans and jars and exposure to high heat under pressure (canning). High-heat treatment for a short period of time (pasteurization). Freezing and vacuuming to dry foods (lyophilization). Use of more than one food processing type (for example, canning and use of preservatives). Use of salt or sugar to draw water out of foods (preservatives).
Use of more than one food processing type (for example, canning and use of preservatives).
Please recall what you have learned about microbial metabolism and food processing methods and choose the best method for prevention of food spoilage for the food type below. There is a photo of bacon. Use of salt or sugar to draw water out of foods (preservatives). Use of more than one food processing type (for example, canning and use of preservatives). Packaging into cans and jars and exposure to high heat under pressure (canning). High-heat treatment for a short period of time (pasteurization). Freezing and vacuuming to dry foods (lyophilization).
Use of salt or sugar to draw water out of foods (preservatives).
Which of the following are properties of exotoxins? Select all that apply. Exotoxins are extremely heat stable. Very small amounts of exotoxin can be lethal. Exotoxins are released from the cell during death or replication. Exotoxins are protein molecules. Exotoxins target specific cellular structures or molecules. Exotoxins are produced primarily by gram-negative bacteria.
Very small amounts of exotoxin can be lethal. Exotoxins are protein molecules. Exotoxins target specific cellular structures or molecules.
On a global scale, the most important waterborne bacterial pathogens are __________. Vibrio cholerae and norovirus Salmonella enterica serovar Typhi and Escherichia coli Vibrio cholerae and Legionella pneumoniae Vibrio cholerae and Salmonella enterica serovar Typhi
Vibrio cholerae and Salmonella enterica serovar Typhi
Acute Infection
Viral infection at the apical cell surface
Systemic Infection
Viral infection at the basolateral cell surface
Probes used for detecting genetic sequences are frequently composed of 70) ______ A) synthetic nucleic acids and labeled conjugates, such as fluorescent dyes. B) nitrocellulose. C) agarose. D) silicon chips. E) restriction enzymes.
a
An ancient application of biotechnology is a. production of cheese. b. selective breeding of plants. c. the practice of medicine. d. traditional agriculture. e. both traditional agriculture and the selective breeding of plants.
a
If a researcher used Escherichia coli DNA polymerase instead of Thermus aquaticus DNA polymerase in the PCR procedure, what would be the result? 32) ______ A) DNA replication would stop after one cycle. B) DNA replication would not occur at all. C) Many mistakes would occur. D) DNA replication would occur twice as fast as normal. E) DNA replication would occur more slowly than normal.
a
If all the following DNA fragments were analyzed on an electrophoresis gel, which one would migrate farthest from the negative electrode? a. 250 base pairs b. 750 base pairs c. 1000 base pairs d. 2500 base pairs e. 5000 base pairs
a
In the 20th century, scientists harnessed the natural metabolic reactions of bacteria to make ________ for the first time in an industrial setting. 52) ______ A) acetone B) wine C) soy sauce D) cheese E) alcohol
a
Injecting DNA into cells can be accomplished using 73) ______ A) micropipettes, or compressed air and gold beads. B) nitrocellulose membranes. C) micropipettes. D) compressed air and gold beads. E) silicon chips and nucleic acids.
a
Recent modifications of microbes have produced 5) _______ A) microbes which facilitate extraction of metals from mining ores. B) improved beer production. C) microbes capable of producing crude oil. D) new emerging diseases. E) a cure for AIDS.
a
Recombinant DNA technology can be most accurately defined as the a. deliberate modification of the genome of an organism for practical purposes. b. selective breeding of organisms to create new combinations of traits. c. study of genetic expression in microbes. d. study of replication and recombination in microbes. e. use of microorganisms to produce useful products.
a
Recombinant DNA technology can be most accurately defined as the 30) ______ A) deliberate modification of the genome of an organism for practical purposes. B) study of replication and recombination in microbes. C) study of genetic expression in microbes. D) selective breeding of organisms to create new combinations of traits. E) use of microorganisms to produce useful products.
a
Subunit vaccines are safer than traditional vaccines because they 4) _______ A) are acellular and do not pose a risk for causing the disease. B) are administered in food. C) do not pose a risk for causing the disease. D) are acellular. E) are acellular and can be administered in food.
a
The procedure used to identify individuals by their unique genetic sequences is known as a. DNA fingerprinting. b. DNA sequencing. c. microarray analysis. d. northern analysis. e. xenotransplantation.
a
The procedure used to identify individuals by their unique genetic sequences is known as 23) ______ A) DNA fingerprinting. B) northern analysis. C) DNA sequencing. D) microarray analysis. E) xenotransplantation.
a
The sequencing and analysis of an organism's genetic information is called 44) ______ A) genomics. B) northern blotting. C) gene therapy. D) PCR. E) protein synthesis.
a
Which of the following recombinant tools is NOT used in DNA fingerprinting? 39) ______ A) reverse transcription B) restriction enzyme digestion C) gel electrophoresis D) PCR E) neither PCR nor gel electrophoresis is used.
a
Which of the following would be an appropriate sequence of temperatures for PCR? 49) ______ A) 94°C, 65°C, 72°C B) 65°C, 72°C, 94°C C) 72°C, 65°C, 94°C D) 94°C, 37°C, 55°C E) 94°C, 55°C, 37°C
a
Which of the following would contain teichoic acids?
a Gram-positive cell wall
Koch's work involving anthrax was significant because it was the first time __________.
a bacterium had been proven to cause a disease
A patient with West Nile viral encephalitis asks his nurse practitioner how he could have contracted the disease. The NP explains that the causative virus is carried by infected mosquitoes from birds to people. This is an example of disease transmission through
a biological vector.
All of the following are common to both the Gram stain and the acid-fast stain EXCEPT
a chemical mordant.
Vibrio cholerae is a human pathogen that causes cholera. It has an unusual shape distinctive of its genus. Considering that it does not have one of the most common bacterial shapes, what is the shape of this species? a rigid spiral shape a spherical shape a curved rod a straight rod
a curved rod
Blood agar is an example of which of the following?
a differential medium and a complex medium
A patient reported a headache, chills, vomiting, and diarrhea that occurred 12 hours after having a meal at home that included chicken. The physician suspected which type of organism? norovirus a food infection, most likely Enterohemorrhagic E. coli or Shigella a food infection, most likely Salmonella a food intoxication, most likely from Staphylococcus
a food infection, most likely Salmonella
Which of the following is predicted to result in the largest disease outbreak? a pathogen with a high R0 in an immunologically naïve population a pathogen with a high R0 in an immunized population a pathogen with a low R0 in an immunologically naïve population a pathogen with a high R0 in an immunized population
a pathogen with a high R0 in an immunologically naïve population
If a new bacterial pathogen entered a human body through an accidental needle stick, the first cell that would try to kill the pathogen would likely be
a phagocyte.
Which of the following is normally found at the 5' end of a DNA strand?
a phosphate group
A cell that uses an organic carbon source and obtains energy from light would be called a
a photoheterotroph
An aquatic microbe that can grow only near the surface of the water is probably which of the following?
a phototroph
Terry is a Physician Assistant. She is working under the supervision of Dr. Elizabeth Carroll. Terry trusts Dr. Carroll and knows she is an extremely competent and compassionate doctor. They have been a team for about two years, and it works out perfectly because Terry is a morning person and Dr. Carroll is not. Unless there is a difficult case, Terry makes all the early morning rounds of Dr. Carroll's patients at the two local hospitals, and then goes home for an early lunch with her kindergartner son. Later, she sees non-critical care patients at Dr. Carroll's office for a few hours. Unless there is a seriously ill patient, Dr. Carroll will start work a little later in the morning and end her day with the evening rounds at the hospital. This morning, Terry is checking in on a new patient, Mr. Lane, at St. John's Hospital. Mr. Lane has a history of acute myeloid leukemia (AML), and Dr. Carroll admitted him yesterday. According to the chart, Mr. Lane had a blood transfusion yesterday afternoon. Dr. Carroll noted on the chart that Mr. Lane was doing well at 7:00 p.m. However, she noted Mr. Lane may need an additional unit of blood if his blood oxygen values did not return to normal ranges soon. The chart indicates that Mr. Lane had just started receiving an additional unit. Terry enters the room and finds Mr. Lane experiencing chills and shortness of breath. Terry quickly takes the patient's vital signs. She notes that Mr. Lane's heart rate is high, his blood pressure low, and he has a fever. Mr. Lane is alert and complaining that he feels horrible. Terry talks to the floor nurse and finds that she has already stopped the transfusion and alerted the charge nurse, the doctor on call, and Dr. Carroll.The patient is most likely experiencing __________.
a transfusion reaction
Provirus
a virus genome that is integrated into the DNA of a host cell
An animal disease transmitted to humans by direct contact, inhalation of aerosols, or bites is called __________. epizootic a zoophyte enzootic a zoonosis
a zoonosis
Describe the balance between susceptibility (S) and resistance factors (R). a. When S is greater than R, the person is not healthy. b. When S is less than R, the person is healthy. c. When S is equals to R, the person is healthy.
a, b and c
How can viruses so small and yet still be pathogenic?
a, b, and c
The following molecules are involved in the biosynthetic pathway that leads to the formation of DNA and RNA; what is their correct sequence in this pathway? a. PABA b. tetrahydrofolic acid c. purine and pyrimidine nucleotides d. dihydrofolic acid
a, d, b, c
Put the following taxonomic groups in order, from broadest group to most specific group: a. phylum b. genus c. family d. order
a,d,c,b
Drag the labels onto the diagram to identify the components of replicating DNA strands.
a. Parental DNA b. DNA polymerase c. leading strand d. lagging strand e. DNA ligase f. replication fork
Drag the correct labels onto the diagram to identify the structures and molecules involved in translation.
a. mRNA b. small subunit of ribosome c. large subunit of ribosome d. amino acid e. tRNA f. anticodon
Nonspecific permeases
allow a variety of molecules to cross the cytoplasmic membrane.
The figure represents a Petri dish with a fungus (F), shown in darker gray, growing in the midst of bacterial lawn (B), shown in light gray. The relationship between the fungus and the bacteria would best be described as
amensal.
Which of the following is NOT involved in the process of DNA fingerprinting?
addition of fluorescent nucleotides to a DNA sample
What is the action of azoles?
affect cell membrane of fungi
An unknown bacterium was isolated from a patient with pneumonia. To determine the minimum inhibitory concentration of the chosen drug to use to treat the respiratory infection, the doctor must take into account __________. pH of growth medium all of the listed responses are correct time of incubation concentration of amino acids in the medium
all of the listed responses are correct
Deaths because of infectious disease are more common in developing countries, such as Africa, compared to the Americas because of __________. all of the listed responses are correct limited access to clean water limited immunization programs inadequate sanitation
all of the listed responses are correct
Baking bread, creating a genetically modified vegetable, using a microbe to make human insulin . . . Which of these is NOT considered "biotechnology"?
all of these are biotechnology
Which of the following organisms would be most likely to contaminate a jar of pickles?
an acidophile
Specific DNA fragments can be isolated from a mixture of fragments using a. an electrophoresis chamber. b. a gene gun. c. a DNA sequencer. d. a nucleic acid synthesis machine. e. a thermocycler.
an electrophoresis chamber
All of the following might lead to a disease caused by an opportunistic pathogen EXCEPT __________.
an encounter with an infected animal
The distribution of disease can change very quickly. An increase in emerging diseases can be attributed to __________. more people being immunized more people moving away from cities unchanging climate an increase in international travel
an increase in international travel
The condition known as microbial antagonism may be defined as
an unsuccessful microbial invasion due to the presence of preexisting microbes.
Which of the following would be a useful phenotypic marker on a vector? a. Reverse transcriptase b. Antibiotic resistance gene c. Restriction enzyme d. Ligase
b. Antibiotic resistance gene
What type of epidemiological study is exemplified in this case?
analytical
This child has had a moderate reaction to his first bee sting. If he were to be stung again, the signs and symptoms could be severe and life-threatening due to constriction of airways. What is this systemic reaction called, and what would the treatment of choice be?
anaphylaxis; epinephrine
The rings
anchor the flagellum to the cell membrane.
Which of the following is generally NOT considered an ethical issue regarding recombinant DNA technology
answering basic research questions
Which of the following is generally NOT considered an ethical issue regarding recombinant DNA technology?
answering basic research questions
Considering industrial products, which of the following is not a primary microbial metabolite? amylase produced by Aspergillus oryzae proteases made by Bacillus subtilis and other microbes pectinase produced by Clostridium antibiotic produced by Penicillium notum
antibiotic produced by Penicillium notum
Which of the following would be a useful phenotypic marker on a vector?
antibiotic resistance gene
Bacillus licheniformis secretes a compound that inhibits the growth of other Gram-positive bacteria. This is an example of a(n)
antibiotic.
A triplet of nucleotides in the tRNA is called ________. It is a one-word answer and spelling matters.
anticodon
Which of the following OTC medications would provide the best relief of symptoms?
antihistamines
Disinfecting agents naturally produced by microorganisms are
antimicrobials.
Small RNAs that bind to an mRNA and alter its expression are known as (antisense/probes/ restriction) RNAs.
antisense
Small RNAs that bind to an mRNA and alter its expression are known as (ntisense/probes/restriction) RNAs.
antisense
Which of the following could be used to reduce production of harmful proteins in diseased animals? a. gene mapping b. modified mRNAs c. expression vectors d. PCR e. antisense RNAs
antisense RNAs
An antimicrobial chemical used on the skin is usually called a(n) __________.
antiseptic Antiseptics often contain the same chemicals as disinfectants, but they are less concentrated and therefore safer to use on living tissues.
The resolution of a microscope lens is a function of the lens' (aperture/color/contrast).
aperture
Subunit vaccines are safer than traditional vaccines because they
are acellular and do not pose a risk for causing the disease
Subunit vaccines are safer than traditional vaccines because they
are acellular and do not pose a risk for causing the disease.
Subunit vaccines are safer than traditional vaccines because they do not pose a risk for causing the disease. are acellular and can be administered in food. are acellular. are acellular and do not pose a risk for causing the disease. are administered in food.
are acellular and do not pose a risk for causing the disease.
Subunit vaccines are safer than traditional vaccines because they a. are administered in food. b. are acellular and do not pose a risk for causing the disease. c. are acellular and can be administered in food. d. are acellular. e. do not pose a risk for causing the disease.
are acellular and do not pose a risk for causing the disease.
Lyme disease and syphilis are similar in that they __________. are both chronic infections that involve the nervous system are both contracted by person-to-person contact are both caused by spirochetes and are chronic infections that involve the nervous systems are both caused by spirochetes
are both caused by spirochetes and are chronic infections that involve the nervous systems
Peter was rushed to the emergency because he was bitten by a mad dog. The wound was washed with soap and water and he was immediately injected with rabies vaccine. The injection will be repeated five more times (after 3, 5, 7, 14 and 28 days). What type of specific immunity Peter will acquire?
artificial active
The restriction enzyme KpnII probably originated __________
as the second discovered restriction enzymes from Klebsiella pneumoniae bacterium Submit
GAU codes for
aspartic acid.
A pathogen must __________ in order for it to cause disease. secrete a toxin attach enter a host attach and multiply
attach and multiply
Which of the following techniques can be used to sterilize microbiological media?
autoclaving
Examples of recent accomplishments in the use of recombinant DNA technology include a. a cure for HIV. b. gene therapy to correct an immune system deficiency in humans. c. production of a peach-apple hybrid plant. d. production of gene modified human embryos. e. production of new emerging disease agents.
b
In the figure, which line best depicts a facultative anaerobe in the absence of O2?
b
Replacing the defective gene responsible for sickle-cell anemia is an example of a. DNA fingerprinting. b. gene therapy. c. genetic screening. d. producing a transgenic organism. e. recombinant therapy.
b
Some of the strongest opposition to the application of recombinant DNA technology concerns 8) _______ A) sequencing of the human genome. B) modification of food crops. C) correcting gene defects in animals. D) DNA fingerprinting. E) pest control measures.
b
Synthesis of cDNA requires the use of 69) ______ A) fluorescent synthetic nucleotides. B) reverse transcriptase. C) DNA ligase. D) restriction enzymes. E) agarose.
b
The natural role of restriction enzymes in bacteria is to 61) ______ A) allow transposons to move to another place in the chromosome. B) protect the cell from invading phages. C) allow cells to accept foreign DNA. D) make conjugation more efficient. E) provide the cell with new phenotypes, such as antibiotic resistance.
b
Which of the following is essential in PCR? 13) ______ A) reverse transcriptase B) both DNA primers and DNA polymerase C) DNA polymerase D) DNA primers E) antisense RNAs
b
Which of the following microbes has been genetically engineered to contain a protein that helps protect crops from freezing? 12) ______ A) Escherichia coli B) Pseudomonas C) Salmonella D) Bacillus thuringiensis E) Deinococcus radiodurans
b
Which of the following restriction enzyme sites would produce blunt-ended fragments? (The arrow represents the cutting site of the enzyme.) 67) ______ A) G↓AATTC B) CCC↓GGG C) C↓CGG D) A↓AGCTT E) G↓GATCC
b
Put the following events in the construction of a recombinant DNA molecule in the correct order: a. Plasmid is introduced into bacteria b. Gene of interest and plasmid DNA are cut by restriction enzyme c. Gene of interest is joined to plasmid DNA d. Bacteria are grown of on suitable culture medium.
b, c, a, d
Put the following routes of administration in order, from the route that results in the highest concentration of drug in the bloodstream to the route that results in the lowest concentration: a. topical b. intravenous c. oral d. intramuscular
b, d, c, a
Arrange the following steps to describe transformation in bacteria. a) Fragment of donor DNA enters competent bacteria. b) Bacteria die, their DNA are degraded and released in the environment. c) Fragment of donor DNA integrates with the recipient bacteria. d) Transformants are formed.
b-a-c-d
Arrange the following to illustrate phagocytosis. a. Elimination b. Chemotaxis c. Phagosome Maturation and Microbial Killing d. Adhesion e. Ingestion
b-d-e-c-a
Crop plants modified to be resistant to insect damage produce Bt toxin from a (bacterial/fungal/synthetic) gene.
bacterial
R-plasmids are most likely acquired via Check all that apply. transformation. translation. transduction. bacterial conjugation.
bacterial conjugation
You have isolated a microorganism that is green, photosynthetic, has a cell wall, and does NOT possess a nucleus. This organism is a(n) __________.
bacterium
Alexis's group presentation on the benefits of microbes is a success, and her group earns an "A" for the project. The last few weeks of the course focus on industrial microbiology. Industrial microbiology began as large-scale food fermentations, specifically for dairy products and alcoholic beverages such as those mentioned previously. As technology progressed, so did the number of products that came to be made on a large scale. Today, industrial microbiology applies the idea of biotechnology to produce commercially valuable substances. Which of the following are examples of commercial microbial products? Select all that apply/ baker's yeast, Rhizobium, and Bt-toxin amylase, glucose isomerase, proteases, and rennin antibiotics, vaccines, and steroids glutamic acid, lysine, methionine, and phenylalanine
baker's yeast, Rhizobium, and Bt-toxin amylase, glucose isomerase, proteases, and rennin antibiotics, vaccines, and steroids glutamic acid, lysine, methionine, and phenylalanine
Which of the following is a type of blood cell that undergoes degranulation in type I hypersensitivity reactions?
basophil
They are leukocytes that stain blue with the basic dye like methylene blue. It is a one-word answer (plural) and spelling matters.
basophils
Why is the drug actinomycin used only in research applications or in the treatment of cancer?
because it is active against both prokaryotic and eukaryotic cells
Drag the characteristics to the correct blood type.
blood group A: A antigen on RBC B antibodies present blood group B: B antigen on RBC A antibodies present blood group AB: no antibodies present A & B antigen on RBC Blood group O: A & B antibodies present no antigen on RBC
The bacterium Staphylococcus aureus is commonly found in the nasal cavity of healthy people. If inhaled into the lungs, however, it may cause pneumonia. Staphylococcus aureus is best described as
both resident microbiota and opportunistic pathogen.
What bacteria (G+ or G-) are favored to grow in MacConkey agar (MAC)? What type of culture medium is MAC based on function?
both selective and differential culture medium
The broth dilution test can provide information for determining
both the MIC and the MBC (with an additional step).
How can you control microorganisms?
by killing microorganisms by inhibiting growth of microorganisms by removing microorganisms
An effective tool for screening a large number of genetic sequences at once is known as 53) ______ A) gel electrophoresis. B) cDNA synthesis. C) microarray. D) FISH. E) restriction analysis.
c
If you started with a single DNA molecule, how many would you have at the end of six PCR cycles? 42) ______ A) 6 B) 32 C) 64 D) 16 E) 100
c
In Southern blotting, DNA molecules are immobilized on a. agarose. b. gold beads. c. nitrocellulose membranes. d. paper. e. silicon chips.
c
Mutagens are useful in biotechnology research for a. producing DNA fragments for cloning. b. producing new organisms which have beneficial traits from two or more organisms. c. producing organisms with altered phenotypes. d. removing undesirable traits from microbes. e. selecting genetic mutants resistant to radioactivity.
c
Mutagens are useful in biotechnology research for 22) ______ A) producing new organisms which have beneficial traits from two or more organisms. B) removing undesirable traits from microbes. C) producing organisms with altered phenotypes. D) producing DNA fragments for cloning. E) selecting genetic mutants resistant to radioactivity.
c
Some of the strongest opposition to the application of recombinant DNA technology concerns a. correcting gene defects in animals. b. DNA fingerprinting. c. modification of food crops. d. pest control measures. e. sequencing of the human genome.
c
Specific DNA fragments can be isolated from a mixture of fragments using a. a DNA sequencer. b. a gene gun. c. an electrophoresis chamber. d. a nucleic acid synthesis machine. e. a thermocycler.
c
Synthetic nucleic acids are produced 75) ______ A) by a series of chemical steps carried out on the lab bench. B) by PCR of the desired sequence. C) using computer-controlled machines to assemble a single strand nucleic acid. D) using a recombinant cell which produces a transcript of the desired sequence. E) using restriction enzymes to cut a fragment out of a plasmid containing the desired sequence.
c
Synthetic nucleic acids are produced using a. a series of chemical steps carried out on the lab bench. b. a thermal cycler. c. computerized assembly using replication enzymes in vitro. d. recombinant microbes. e. restriction enzyme digestion of DNA.
c
Which of the following devices is used for PCR? 17) ______ A) a nucleic acid synthesis machine B) a gene gun C) a thermocycler D) an electrophoresis chamber E) a DNA sequencer
c
Pathogenic bacteria
can be identified and classified by differences in their flagellar proteins.
Which of the following is NOT a goal of recombinant DNA technology? 15) ______ A) being able to remove or correct damaging traits in humans B) combining genetic material from more than one organism to produce new useful organisms C) making it possible to clone humans D) creating organisms capable of producing useful products E) eliminating undesirable traits from livestock or crops
c
Which of the following restriction enzyme sites would produce blunt-ended fragments? (The arrow represents the cutting site of the enzyme.) a. A↓AGCTT b. C↓CGG c. CCC↓GGG d. G↓AATTC e. G↓GATCC
c
________ are used for cutting DNA molecules into fragments. 62) ______ A) DNA polymerase and DNA ligase B) Mutagens C) Restriction enzymes D) Antisense RNAs E) RNA polymerases
c
Put the following events in the construction of a recombinant DNA molecule in the correct order: a. ligation of desired gene to plasmid DNA b. introduction of the plasmid into bacteria c. restriction enzymes cut gene of interest and plasmid DNA d. growth of cells on an antibiotic-containing medium
c, a, b, d
What is the difference between a missense mutation and a nonsense mutation? a. A missense mutation changes the code for an amino acid into a stop codon, whereas a nonsense mutation changes the code for one amino acid into the code for a different one. b. A missense mutation is a change in nucleotide sequence that does not change the amino acid sequence in the polypeptide, while a nonsense mutation changes the codon to code for a different amino acid. c. A missense mutation codes for an amino acid that is incorrect for the polypeptide, while a nonsense mutation changes a codon for an amino acid into a stop codon. d. A missense mutation codes for an amino acid that is incorrect for the polypeptide, whereas a nonsense mutation changes a stop codon into a codon for an amino acid.
c. A missense mutation codes for an amino acid that is incorrect for the polypeptide, while a nonsense mutation changes a codon for an amino acid into a stop codon.
What is the purpose of a primer during DNA replication? a. It catalyzes the addition of nucleotides to the growing DNA strand.r b. It attaches newly synthesized DNA strands to each other. c. It provides an initial 3′ hydroxyl group for DNA polymerase to add nucleotides. d. It breaks the hydrogen bonds between the two DNA strands, separating them.
c. It provides an initial 3′ hydroxyl group for DNA polymerase to add nucleotides.
The immune response of a host against an invading bacterium is often triggered by surface components on the bacterium that are recognized as "non-self" or "foreign" by the host. These non-self components, often protein or polysaccharide in nature, are referred to as antigens. The host responds to these antigens by making antibodies that will react with invading bacteria and mark them or tag them for destruction by phagocytes. Indicate the bacterial structures that are likely to be antigens, to which host antibodies bind, marking the invader for phagocytosis
capsule flagella fimbriae cell wall
What is the enzyme that can neutralize the effects of hydrogen peroxide?
catalase
Hydrogen peroxide does NOT make a good antiseptic for open wounds because __________.
catalase in human tissues neutralizes it Human cells, like many other cells, contain protective enzymes such as catalase that are used to guard against the toxic byproducts of oxygen and its metabolism.
What is the target structure of polymixin?
cell membrane
Which of the following is common to both Sanger sequencing and next-generation sequencing?
chain terminating nucleotides
An exotoxin that has the ability to kill or damage host cells is referred to as a(n)
cytotoxin.
The relationship between two organisms where one organism is benefited and the other organism is not affected is called ________. The organism that is benefited is called ________.
commensalism ; commensal
All students that ate in the school dining hall on Monday developed stomach cramps and diarrhea. The student clinic was overwhelmed with patients. However, by Thursday the number of patients seen in the clinic was back to normal. This could have been caused by a __________. host-to-host epidemic common-source epidemic infectious disease vector-borne disease
common-source epidemic
In 2011, the CDC reported a 28-state outbreak of Listeria monocytogenes that killed 33 people in the United States. The victims were found to have eaten portions of whole cantaloupe melons originating from a single farm in Colorado. The FDA traced the source of bacterial contamination to a piece of used equipment that had been recently purchased to wash the melons, nearby puddles of water, and a truck that hauled spoiled melons to a field to be fed to cattle. This would be an example of __________. zoonotic reservoir water-borne transmission person-to-person transmission common-source transmission
common-source transmission
cDNA stands for
complementary DNA
cDNA stands for __________.
complementary DNA
Drag the steps in a transfusion reaction to the boxes so that the steps are in the correct order.
complementary antibodies bind antigen Antigen-antibody complex binds complement. hemolysis releases hemoglobin free hemoglobin damages kindeys
Synthetic nucleic acids are produced using a. recombinant microbes. b. computerized assembly using replication enzymes in vitro. c. a series of chemical steps carried out on the lab bench. d. restriction enzyme digestion of DNA. e. a thermal cycler.
computerized assembly using replication enzymes in vitro.
A mutation that causes production of a defective pilus in a bacterium will prevent __________.
conjugation
The colon has been described as a living fermentation vessel. Which type of culture system would it most resemble? immobilized cell culture batch culture continuous culture None of the listed responses is correct.
continuous culture
A student develops allergic contact dermatitis after being exposed to formaldehyde in the laboratory. She tries to treat the condition by taking an antihistamine, but the drug has little or no effect. Which of the following treatments should she consider using instead?
corticosteroids
The structural framework in a cell is the
cytoskeleton
Which of the following is/are NOT associated with a type I hypersensitivity?
cytotoxic T cells
A northern blot differs from a Southern blot in the 50) ______ A) presence or absence of a nitrocellulose membrane. B) type of probe used. C) size of the genetic sequences involved. D) type of nucleic acid being isolated. E) number of genetic sequences detected.
d
If you started with a single DNA molecule, how many would you have at the end of six PCR cycles? a. 6 b. 16 c. 32 d. 64 e. 100
d
The DNA double helix can be separated into single strands using 63) ______ A) NaOH. B) reverse transcriptase. C) heat. D) either heat or NaOH. E) heat, NaOH, and reverse transcriptase.
d
Transgenic organisms 2) _______ A) contain cells from other organisms. B) have genomes that have been sequenced completely. C) are the same as clones. D) contain genes from other organisms. E) contain genetically engineered microbes.
d
Two men may be the father of a child. This figure shows the results of a DNA fingerprint analysis to determine paternity. M is the mother, C is the child, A and B are the two men. What is the best interpretation of these results? 48) ______ A) The man identified as A is probably the father. B) Neither man is this child's father. C) Either man could be this child's father. D) The man identified as B is probably the father. E) Paternity cannot be determined from this data.
d
Which of the following is generally NOT considered an ethical issue regarding recombinant DNA technology? 1) _______ A) unforeseen impact on the environment B) screening of humans for genes that predispose them to disease C) the modification of animals to produce pharmaceuticals for humans D) answering basic research questions E) the modification of crop plants
d
Which of the following items is NOT a part of the name of a restriction enzyme? 43) ______ A) the genus of the source bacterium B) the strain of the source bacterium C) Roman numerals to indicate its order of discovery D) the Gram reaction of the source bacterium E) the specific epithet of the source bacterium
d
Which of the following microbes has been genetically engineered to contain a protein that helps protect crops from freezing? a. Bacillus thuringiensis b. Deinococcus radiodurans c. Escherichia coli d. Pseudomonas e. Salmonella
d
Which of the following recombinant tools is NOT used in DNA fingerprinting? a. gel electrophoresis b. PCR c. restriction enzyme digestion d. reverse transcription e. Neither PCR nor gel electrophoresis is used.
d
Which of the following statements regarding vectors is FALSE? 72) ______ A) Cloning vectors frequently contain sequences necessary for expression of inserted sequences. B) Vectors are usually autonomously replicating DNA molecules. C) A useful vector contains multiple restriction sites for insertion of DNA. D) Vectors are generally over 100,000 base pairs in size. E) Cloning vectors include a "marker" to facilitate identification of cells containing them.
d
What is the correct order of binary fission from first to last? a. DNA is moved into each future daughter cells. b. Cross wall formation. c. Cell divides into two cells. d. DNA replicates e. Cells separate
d-a-b-c-e
Arrange the following steps in order from first to last to prepare a heat fixed bacterial smear. a. Air dry the thin film. b. Spread a thin film of bacteria over glass slide. c. Pass the slide with the film over flame of Bunsen burner. d. Get a clean glass slide.
d-b-a-c
Which technique would be most useful in diagnosing an infection? a. heat shocking b. DNA sequencing c. southern blotting d. DNA microarray
d. DNA microarray
What characteristic(s) of gel electrophoresis make it an effective technique in genetic research? a. Small DNA is attracted to the negative end, while larger DNA is not. b. Large DNA is attracted to the positive end of the gel. c. Positively charged DNA travels toward the negative electrode. d. Negatively charged DNA travels toward the positive electrode.
d. Negatively charged DNA travels toward the positive electrode.
When the human papillomavirus (HPV) vaccine was first introduced to help prevent cervical cancer as well as anal warts and cancers, it was only recommended for 11- or 12-year-old girls. However, the CDC later expanded its HPV vaccination recommendations to include 11- and 12-year-old boys. By including males, the public health officials hoped to do all of the following EXCEPT __________. decrease the incidence of cervical cancer in women protect men from anal warts and cancer increase herd immunity to HPV decrease the basic reproductive number (R0) of HPV
decrease the basic reproductive number (R0) of HPV
Predict which of the following outcomes would result from taking an antihistamine.
decreased histamine-based stimulation of cells decreased permeability of blood vessels decreased mucus secretions
A laboratory recipe lists sucrose, an ammonia compound, calcium salts and a buffer as the ingredients for a microbiologic medium. These are added to water and autoclaved. What type of medium does this protocol produce?
defined broth
When a nurse rubs your skin with rubbing alcohol prior to administering an injection, what process(es) is he carrying out? Select all that apply.
degerming antisepsis
Recombinant DNA technology can be most accurately defined as the a. selective breeding of organisms to create new combinations of traits. b. study of replication and recombination in microbes. c. study of genetic expression in microbes. d. deliberate modification of the genome of an organism for practical purposes. e. use of microorganisms to produce useful products.
deliberate modification of the genome of an organism for practical purposes.
CC: Vectors are used in recombinant DNA technology to ____________.
deliver a helpful gene into a recipient cell
Blood agar can support growth of almost all bacteria and it can determine three types of hemolysis. What type of culture medium based on function is blood agar?
differential culture medium only
If a person with a cold sneezed directly in your face, this would be an example of which type of contact transmission?
droplet
Selective toxicity means the ________.
drug is more harmful to the pathogens than to human cells
Human normal microbiota begin to develop ________
during birth
A library of cloned sequences representing the expressed genes of an organism is known as a 33) ______ A) microarray. B) gene library. C) FISH library. D) DNA fingerprint. E) cDNA library.
e
DNA fingerprinting can be used a. in forensic investigations. b. to detect unculturable organisms. c. to generate cDNA clones. d. to generate cDNA clones and libraries. e. for forensics and detection of unculturable organisms.
e
In gel electrophoresis, DNA molecules move toward the ________ electrode because they have an overall ________ charge. 56) ______ A) negative; negative B) negative and positive; neutral C) negative; positive D) positive; positive E) positive; negative
e
Injecting DNA into cells can be accomplished using a. compressed air and gold beads. b. micropipettes. c. nitrocellulose membranes. d. silicon chips and nucleic acids. e. micropipettes, or compressed air and gold beads.
e
Probes used for detecting genetic sequences are frequently composed of a. gold beads coated with DNA. b. plasmids with a marker sequence. c. restriction enzymes. d. silicon chips. e. synthetic nucleic acids and labeled conjugates, such as fluorescent dyes.
e
Subunit vaccines are safer than traditional vaccines because they a. are acellular. b. are administered in food. c. do not pose a risk for causing the disease. d. are acellular and can be administered in food. e. are acellular and do not pose a risk for causing the disease.
e
Synthesis of cDNA requires the use of a. agarose. b. DNA ligase. c. fluorescent synthetic nucleotides. d. restriction enzymes. e. reverse transcriptase.
e
Synthetic nucleic acids are useful as a. antisense RNAs. b. DNA probes. c. primers for PCR. d. DNA probes and antisense RNAs. e. DNA probes, primers, and antisense RNAs.
e
Synthetic nucleic acids are useful as 59) ______ A) DNA probes and antisense RNAs. B) primers for PCR. C) antisense RNAs. D) DNA probes. E) DNA probes, primers, and antisense RNAs.
e
The detection of DNA by FISH makes use of a. compressed air and gold beads. b. DNA polymerase and DNA ligase. c. restriction fragments. d. reverse transcriptase and DNA polymerase. e. synthetic DNAs and fluorescent tags.
e
What are the "sticky ends" produced by some restriction enzymes? a. Sticky ends are able to hydrogen bond with complementary strands. b. Sticky ends are DNA strands with an extra hydroxyl group on the end. c. Sticky ends are short single-strand ends of a DNA molecule. d. Sticky ends are DNA strands able to form phosphate bonds with free DNA ends. e. Sticky ends are short single-strand ends of DNA able to hydrogen bond with complementary strands.
e
Which of the following is essential in PCR? a. antisense RNAs b. DNA polymerase c. DNA primers d. reverse transcriptase e. both DNA primers and DNA polymerase
e
Which of the following microbes produces a protein that kills a variety of insect pests? 51) ______ A) Thermus aquaticus B) Plasmodium falciparum C) Pseudomonas D) Haemophilus influenzae E) Bacillus thuringiensis
e
Which of the following procedures would be used to introduce DNA into a single mouse cell? 29) ______ A) gene gun B) Southern blotting C) electroporation D) protoplast fusion E) microinjection
e
Which of the following would be an appropriate sequence of temperatures for PCR? a. 65°C, 72°C, 94°C b. 72°C, 65°C, 94°C c. 94°C, 37°C, 55°C d. 94°C, 55°C, 37°C e. 94°C, 65°C, 72°C
e
The emergent H5N1 strain of avian influenza can occasionally be transmitted from birds to humans with a resulting 60% mortality rate (compared with a 2.5% mortality rate for the 1918 pandemic influenza). In 2012, after a single dead chicken in a wholesale market in Hong Kong tested positive for H5N1, all 17,000 chickens in the market and surrounding area were culled. This was an attempt to__________. quarantine . prevent migration. eliminate a vector. eliminate a reservoir.
eliminate a reservoir
Axial filaments are composed of
endoflagella
Cellular mediated immunity is responsible for ________ antigens and humoral immunity is responsible for ________ antigens.
endogenous ; exogenous
Alcohols at 70% can effectively inactivate (all/enveloped/nonenveloped) viruses.
enveloped
Seventy percent alcohol is effective against
enveloped viruses
Restriction (enzymes/proteases/polymerases), first isolated from bacterial cells, cut DNA molecules at specific sites.
enzymes
It is an abnormally high number of eosinophils in the blood, is often indicative of helminth infestation or allergies. It is a one-word answer and spelling matters.
eosinophilia
How would you classify this abrupt jump in cases of legionellosis in Louisiana?
epidemic
Which of the following belongs to our 1st and second lines of defense?
epithelium of mucus membranes
When treating a fungal infection, the best target for selective toxicity would be __________. ergosterol synthesis cell division proteins polypeptide elongation lipid synthesis
ergosterol synthesis
Which of the following antimicrobial drugs would likely be useful to treat a staphylococcal infection?
erythromycin
Which of these microbial products is needed to produce "gasohol"? ethanol aspartame citric acid methanol hyaluronidase
ethanol
Which of the following would be used to sterilize a mattress?
ethylene oxide
Several farms in your area have been applying too much fertilizer, and runoff from the fields has carried phosphorus into a nearby lake, allowing microbes in the lake to bloom. Unfortunately, what is good for these microbes is bad for the fish, which all die from lack of oxygen. What term describes what happened in the lake? eutrophication deamination respiration oxidation
eutrophication
Drug-resistant populations of microbes arise when
exposure to drugs selectively kills sensitive cells, allowing overgrowth of resistant cells.
Thymus cells are specialized to participate in clonal deletion because they have the ability to __________.
express all of the body's autoantigens
A collection of bacterial clones each of which contains a portion of the gene sequences of an organism is known as a microarray of that organism's genome.
f
A subunit vaccine is prepared by extensive manipulation of the genome of the pathogen. 19)
f
Restriction enzymes are useful only on synthetic DNAs
f
Sticky-end fragments generated by EcoRI will hydrogen bond to any other sticky-end sequence.
f
What groups of microorganisms grow throughout thioglycollate agar tubes but there is more growth on the surface or near the surface. It is a two-word answer and spelling matters
facultative anaerobes
Louis Pasteur demonstrated that fermentation to produce alcohol is caused by
facultative anaerobes.
If an anti-A serum is shown in this agglutination test, then the patient's blood type must be A.
false
Restriction enzymes are useful only on synthetic DNAs.
false
The decimal reduction time is the time required to kill all the microbes in a given sample.
false
C. difficile infections are on the rise, both in elderly hospitalized patients receiving antibiotics and in younger populations having no previous contact either with a hospital environment or antibiotics. What is the most effective treatment for chronic C. difficile infections? high doses of antibiotics medical management with intravenous fluids to prevent dehydration and shock fecal transplants from a healthy donor surgical removal of the colon if antibiotic therapy fails
fecal transplants from a healthy donor
Bread dough rises because of _____ by Saccharomyces cerevisiae. oxidation pickling spoilage fermentation
fermentation
A scientist develops a new medication that is a protein compound and that must be administered by injection. Which of the following would be the most effective and safest means of preparing a sterile solution of the new medication?
filtration
The drugs polyenes are effective against what group of microorganisms?
fungi
A microorganism has the following characteristics: eukaryotic, multicellular, has cell walls, and grows in long filaments. What is its general classification?
fungus
Enveloped viruses penetrate by...?
fusing their envelop to the host cells plasma membrane.
The Ames test involves mutants of Salmonella that __________ the ability to make histidine in the __________ of a suspected mutagenic chemical.
gain; presence
The ability of Vibrio cholerae to cause disease depends on a number of factors. Which of the following are requirements for causing disease within a host? Select all that apply. gaining access to the host via a portal of entry depleting the host of nutrients at the site of infection adherence to host tissues direct damage of host tissues evasion of host defenses production of exotoxins
gaining access to the host via a portal of entry adherence to host tissues evasion of host defenses
Double strand DNA fragments are separated by size using
gel electrophoresis
Double strand DNA fragments are separated by size using
gel electrophoresis.
DNA encoding a normal gene is inserted into cells from a patient with a defective form of the gene. Recombinant cells are identified and isolated, and returned to the patient's body. This is an example of
gene therapy
DNA encoding a normal gene is inserted into cells from a patient with a defective form of the gene. Recombinant cells are identified and isolated, and returned to the patient's body. This is an example of a. biotechnology. b. genotyping. c. gene therapy. d. genetic fingerprinting. e. genomics.
gene therapy
Replacing a patient's defective gene with a fragment containing a functional gene is
gene therapy
Examples of recent accomplishments in the use of recombinant DNA technology include a. production of gene modified human embryos. b. production of new emerging disease agents. c. a cure for HIV. d. gene therapy to correct an immune system deficiency in humans. e. production of a peach-apple hybrid plant.
gene therapy to correct an immune system deficiency in humans.
DNA encoding a normal gene is inserted into cells from a patient with a defective form of the gene. Recombinant cells are identified and isolated, and returned to the patient's body. This is an example of
gene therapy.
Replacing a patient's defective gene with a fragment containing a functional gene is
gene therapy.
Replacing a patient's defective gene with a fragment containing a functional gene is gene therapy. gene cloning. genomics. gene mapping. gene selection.
gene therapy.
Replacing the defective gene responsible for sickle-cell anemia is an example of a. gene therapy. b. DNA fingerprinting. c. recombinant therapy. d. genetic screening. e. producing a transgenic organism.
gene therapy.
The process of locating genes within the nucleic acid of an organism is called (genetic/library/clone) mapping.
genetic
The procedure used to determine whether a person has a heritable disease is known as
genetic screening
__________ can be used to advise prospective parents about their risk of transmitting genetic disorders, such as Huntington's Disease, to their offspring.
genetic screening
The procedure used to determine whether a person has a heritable disease is known as
genetic screening.
The sequencing and analysis of an organism's genetic information is called
genomics
The sequencing and analysis of an organism's genetic information is called
genomics.
A microbial ecologist is studying bacteria and archaea living in a stream. She is particularly interested in three different species of acidophilic archaea because all three are performing metabolically similar processes. These three microbes make up a guild. population. microbiome. microhabitat.
guild
Spallanzani's experiments concerning spontaneous generation were NOT universally accepted because __________. View Available Hint(s)
he eliminated air from his flasks by sealing them
For many years the CDC focused its seasonal influenza vaccination efforts on those groups in the population who suffered the highest influenza mortality rates, including the elderly aged 65 years and older. However, starting in 2008 the CDC shifted their focus to school-aged children and began recommending the vaccine for everyone aged at least 6 months. Research had shown no evidence for any protective effect of the vaccine in the elderly. By changing the recommendations for who should be vaccinated, the CDC planned to better protect the elderly by means of__________. vaccination. herd immunity. direct contact. acquired immunity.
herd immunity
Compared to moist heat methods, dry heat needs which of the following in order to sterilize effectively?
higher temperature and increased time
A girl with a peanut allergy is accidentally exposed to a peanut butter sandwich in a classmate's lunch at school. She almost immediately finds it difficult to breathe and collapses. Her anaphylaxis results from the release of
histamine
What is urticaria?
hives
chapter 18
homework
CONJUGATION PICTURES
horizontal picture with the 3 paired cells depicting the F factor and mating bridge
Rank the following events in order from GREATEST to LEAST contribution to the spread of antibiotic resistance in bacterial populations. View Available Hint(s)
horizontal transfer vertical transfer new mutations
What is the reservoir for this disease organism, Salmonella enterica serotype Typhi?
humans
Which of the following enzymes breaks down the "glue" that holds cells together? Hyaluronidase Streptokinase Fibrinolysin Collagenase
hyaluronidase
Which of the following toxic forms of oxygen is IMPROPERLY paired with the detoxifying enzyme or molecule?
hydroxyl radical: peroxidase
Healthcare-associated (Nosocomial) infections that results from modern medical procedures is called ________.
iatrogenic
Type I hypersensitivity is also known as
immediate
Microbial enzymes are used to biodegrade plastics. as a component of fabric dyes. as preservatives. in the production of linen. in spot removers.
in spot removers.
The influenza vaccine is an example of a(n)
inactivated killed vaccine.
It is a general, nonspecific response to tissue damage resulting from a variety of causes, including infection with pathogens. The responses include redness, localized heat, edema and pain. It is a one-word answer and spelling matters
inflammation
Which of the following methods of inserting DNA into cells might be used on plant seeds?
injection
Which of the following is most likely to cause disease? injection of 101 cells of a highly virulent bacterial species into a mouse injection of 106 cells of a low virulent bacterial species into a mouse injection of 105 cells of a highly virulent bacterial species into a mouse injection of 103 cells of a moderately virulent bacterial species into a mouse
injection of 105 cells of a highly virulent bacterial species into a mouse
The first and second lines of defense against microbial invasion are part of
innate immunity.
An epidemiologist is investigating a new disease and observes what appear to be bacteria inside tissue cells in clinical samples from victims. The scientist wants to try to isolate the bacteria in the lab. What culture conditions are most likely to be successful?
inoculation of cell cultures
Electroporation is a technique used for
inserting DNA into cells
Protoplast fusion is a technique used for __________.
inserting DNA into cells
Which of the following is not a step in a typical PCR cycle?
insertion
The F plasmid in Hfr cells is ________.
integrated in its chromosome
E. coli (a normal flora of the large intestine) gains access in the urethra and able to invade and colonize. This is an example of what type of how normal flora becomes an opportunist pathogen?
introduction of the normal flora in an unusual site of the body
What is the relationship of wavelength to resolution? Is it inversely proportional or directly proportional?
inversely proportional
A recombinant cell
is a cell that receives DNA from an outside source and incorporates it into its own.
Honey can be stored at room temperature for long periods of time because it
is hypertonic.
Which of the following drugs specifically targets cell walls that contain mycolic acid?
isoniazid
Bacteria of the genus Mycoplasma lack cell walls. What sort of environment do they require for survival?
isotonic
The process of diapedesis is important because __________.
it allows white blood cells to leave the vessel system and attack pathogens in the tissues
Helicobacter pylori is a bacterium found in the stomachs of roughly half of the human population. It is considered to be a pathogen because __________. it can cause chronic inflammation when present, it accounts for the vast majority of stomach microbial biomass it is the only bacterium found in the human stomach it is found in the stomach mucosa rather than the lumen
it can cause chronic inflammation
Borrelia burgdorferi is an interesting spirochete that is unusual when compared to other bacteria. Which of the following is the reason that it is so unusual? it has a cell wall it has ribosomes it has flagella it has a linear chromosome
it has a linear chromosome
A silent mutation is so named because __________.
it has no effect on the overall amino acid sequence
HIV may be transmitted person to person through the exchange of bodily secretions. Which of the following activities would generally NOT transmit the virus?
kissing, with the exchange of saliva
Which of the following was a downfall of the Human Microbiome Project? lack of subject diversity lack of subject numbers too few sample sites lack of female participants
lack of subject diversity
The infection cycle of HIV utilizes a period of dormancy in which the viral genome that is now in a double-stranded DNA form will "hide" in the host cell chromosome. What is this period referred to and what viral derived enzyme is responsible for it?
latency; integrase
The process of freeze-drying microbes to preserve them is
lyophilization
What is the method used for the long term preservation of microorganisms? It is a one-word answer and spelling matters.
lyophilization
What is the ultimate effect of the complement cascade to the pathogens?
lysis of the pathogens
The technique known as real-time PCR is used to
measure the number of copies of a DNA sequence in a sample.
Which of the following is an application of proteases? indigo wine cheese vodka meat tenderizer
meat tenderizer
When a housefly walks across feces containing Salmonella and then walks across food, the fly is serving as a ________.
mechanical vector
Which of the following techniques is most useful for measuring microbial reproduction when the density of a microbial population is very small?
membrane filtration
An effective tool for screening a large number of genetic sequences at once is known as a. restriction analysis. b. gel electrophoresis. c. microarray. d. FISH. e. cDNA synthesis.
microarray
Which of the following procedures might be used to detect the presence of genetic sequences of a virus in a sample?
microarray or PCR
Single-strand DNA molecules are fixed to a glass slide or nylon membrane for the production of
microarrays
Single-strand DNA molecules are fixed to a glass slide or nylon membrane for the production of ________.
microarrays
Single-strand DNA molecules are fixed to a glass slide or nylon membrane for the production of
microarrays.
Which of the following procedures would be used to introduce DNA into a single mouse cell?
microinjection
Which of the following procedures would be used to introduce DNA into a single mouse cell? a. microinjection b. Southern blotting c. electroporation d. gene gun e. protoplast fusion
microinjection
xThe insertion of foreign DNA directly into a cell's nucleus using a glass micropipet is called (microporation/electroporation/microinjection).
microinjections
A measurement of a microbe is reported as 1 × 10-6 m, also known as
micrometers (μμm).
Injecting DNA into cells can be accomplished using
micropipettes, or compressed air and gold beads
Injecting DNA into cells can be accomplished using compressed air and gold beads. b. micropipettes, or compressed air and gold beads. c. micropipettes. d. silicon chips and nucleic acids. e. nitrocellulose membranes.
micropipettes, or compressed air and gold beads
Injecting DNA into cells can be accomplished using
micropipettes, or compressed air and gold beads.
Which of the following symptoms is LEAST characteristic of Clostridium perfringens food poisoning? sudden onset of diarrhea short incubation period moderate vomiting and fever severe abdominal cramping
moderate vomiting and fever
Some of the strongest opposition to the application of recombinant DNA technology concerns
modification of food crops
Some of the strongest opposition to the application of recombinant DNA technology concerns
modification of food crops.
Some of the strongest opposition to the application of recombinant DNA technology concerns a. sequencing of the human genome. b. modification of food crops. c. correcting gene defects in animals. d. DNA fingerprinting. e. pest control measures.
modification of food crops.
Once equilibrium is reached,
molecules move, but there is no net movement in a particular direction.
DNA microarrays can be used to __________.
monitor gene expression
Which of the following cells go out of blood stream and become macrophages in tissues?
monocytes
The incidence of disease in a population is termed the __________. prevalence morbidity mortality outbreak
morbidity
An antibody can pass through the placenta of the mother to the baby. What immunity is acquired by the baby?
naturally acquired passive immunity
In gel electrophoresis, DNA molecules which have a net (negative or positive) charge move towards the (negative or positive) side of the gel
negative; positive
In gel electrophoresis, DNA molecules which have a net (negative or positive) charge move towards the (negative or positive) side of the gel.
negative; positive
Preventing the attachment of the toxin to host cells is which function of the antibody? It is a one-word answer and spelling matters.
neutralization
Which of the following cells kill pathogens by creating chemicals such as O2-, H2O2, hypochlorite and nitric oxide?
neutrophils
In the search for new antimicrobial drugs, to minimize resistance developing scientists should focus on __________. combinations of current antimicrobial compounds new targets of action found only in bacteria new targets of action found only in eukaryotes modifications of current antimicrobial compounds
new targets of action found only in bacteria
In Southern blotting, DNA molecules are immobilized on
nitrocellulose membranes
In southern blotting, DNA molecules are immobilized on
nitrocellulose membranes
In Southern blotting, DNA molecules are immobilized on
nitrocellulose membranes.
In Southern blotting, DNA molecules are immobilized on a. nitrocellulose membranes. Correct b. agarose. c. gold beads. d. silicon chips. e. paper.
nitrocellulose membranes.
A microbiologist discovers a new species of anaerobic bacteria that has the ability to oxidize ammonium. The microbe plays a role in the _____ biogeochemical cycle. carbon phosphorus oxygen nitrogen
nitrogen
Identification of a pathogen in a patient can be done without having to culture the pathogen using __________. none of the listed responses are correct PCR testing if a host specific genetic sequence is known PCR testing if a pathogen specific genetic sequence is not known PCR testing if growing the pathogen in the lab is common
none of the listed responses are correct
While studying protein synthesis in the lab, you experimentally induce a mutation in a bacterium's DNA. You assess the proteins in the mutated bacterium and find that one of them is significantly shorter than its wild-type counterpart. Based on this information, what type of mutation did you induce?
nonsense mutation
a base substitution that changes a codon coding for an amino acid to a stop codon is called a
nonsense mutation
Nearly 90% of all foodborne illnesses are associated with __________. norovirus, Salmonella, Clostridium perfringens, and Campylobacter jejuni norovirus, Salmonella, Clostridium perfringens, and Toxoplasma Salmonella, Clostridium perfringens, Campylobacter jejuni, and Listeria monocytogenes Staphylococcus aureus, Salmonella, Clostridium perfringens, and Campylobacter jejuni
norovirus, Salmonella, Clostridium perfringens, and Campylobacter jejuni
There are some structures that are common to all prokaryotic cells, and others that are only found in some bacterial species or strains. Select the structures below that are found in all bacterial cells.
nucleoid ribosomes cytoplasm plasma membrane
Which of the following is an important virulence factor for dental caries? siderophores endotoxin polysaccharide adhesion pili
polysaccharide adhesion
One advantage of a monogastric digestive system is that __________. more microbes are present digestion occurs more slowly digestion occurs in compartments nutrients are easily accessible to the microbes that aid in digestion and vitamin production
nutrients are easily accessible to the microbes that aid in digestion and vitamin production
Legionella pneumophilia can grow in water and is transmitted in aerosols. Which of the following has NOT been linked to an infection? spas hot water tanks ocean water swimming pools
ocean water
Antimicrobial proteins such as antibodies and complement fraction 3b enhance phagocytosis of pathogens. These chemicals function as
opsonins
The use of salt and sugar in preserving various types of foods is an application of which of the following concepts?
osmotic pressure
In hypertonic solution, water moves (outside or inside) the cell because the concentration of solutes in hypertonic solution is (higher or lower) than the concentration of solutes inside the cell
outside ; higher
Which of the following antimicrobial drugs would likely be useful to treat a methicillin-resistant Staphylococcus aureus infection because it effectively blocks initiation of translation?
oxazolidinones
In the generation of ATP, energy is released when electrons are passed to a series of electron acceptors and finally to oxygen or another inorganic compound. What is this process called?
oxidative phosphorylation
Cytotoxic T cells kill their target by the ________ pathway.
perforin-granzyme and CD95
Bt toxin is important in which of the following agriculture applications?
pest resistance
TLRs are
phagocyte receptors that detect PAMPs.
The second line of defense against invading microbes includes
phagocytic leukocytes.
The antimicrobial chemical pictured above is a(n) (phenolic/surfactant/enzyme) compound found in many consumer products.
phenolic
Natural antiseptics such as pine or clove oil are examples of antimicrobial compounds called (alcohols/phenolics/detergents).
phenolics
PCR stands for
polymerase chain reaction.
PCR stands for polymerase chain reaction. polymerization copying rapidly. polymerase copy reaction.
polymerase chain reaction.
H5N1 avian influenza is widely considered to be the most serious global pandemic threat today and is the target of much worldwide surveillance. The human H5N1 infections thus far have resulted in a mortality rate of almost 60%, underscoring the danger of this virus. Currently, the virus is not readily passed person to person, but reports that the virus may have recently entered (or re-entered) the swine population are of concern because of __________. possible antigenic drift humans typically come into more frequent contact with swine than with birds possible reassortment of the influenza genome with swine and human strains influenza more easily passing from pig to human than from human to human
possible reassortment of the influenza genome with swine and human strains
Which of the following provides the specificity of the PCR reaction?
primers
Small single strand DNA molecules with a fluorescent molecule attached that are used to identify a clone containing a specific gene fragment is called a
probe
Short nucleic acid molecules used to locate complementary sequences in a larger population of molecules are called (probes/primers/vectors).
probes
Mutagens are useful in biotechnology research for
producing organisms with altered phenotypes
Mutagens are useful in biotechnology research for
producing organisms with altered phenotypes.
Mutagens are useful in biotechnology research for a. producing organisms with altered phenotypes. b. producing new organisms which have beneficial traits from two or more organisms. c. removing undesirable traits from microbes. d. producing DNA fragments for cloning. e. selecting genetic mutants resistant to radioactivity.
producing organisms with altered phenotypes.
An ancient application of biotechnology is a. the practice of medicine. b. both traditional agriculture and the selective breeding of plants. c. selective breeding of plants. d. production of cheese. e. traditional agriculture.
production of cheese.
Apoptosis is the process of __________.
programmed cell death
Microorganisms characterized by the absence of a nucleus are called
prokaryotes
Which method of inserting DNA into cells is illustrated in this figure?
protoplast fusion
Which of the following is an INCORRECT pairing?
protozoa; multicellular
The function of a mordant in staining procedures is to
provide contrasting color
Beta-carotene, the biochemical precursor to vitamin A, can be added to rice by using (biotechnology/cloning/ recombinant) DNA technology, thereby increasing its nutritional value.
recombinant
Which of the following is NOT a possible side effect of antimicrobial therapy?
resistance
An antimicrobial disk on a Kirby-Bauer plate that shows no zone of inhibition indicates that the microbe being tested is __________ to the drug. View Available Hint(s)
resistant
Staining is an important way to improve which of the following aspects of microscopy?
resolution and contrast
Which of the following enzymes can make specific cuts in DNA molecules?
restriction enzymes
Synthesis of cDNA requires the use of
reverse transcriptase
Synthesis of cDNA __________ requires the use of
reverse transcriptase.
What subunit of bacterial RNA polymerase recognizes the promoter sequence? It is a two-word answer and spelling matters.
sigma factor
A mutation that affects the genotype of the organism but not the phenotype is called a
silent mutation.
The templates for next-generation sequencing are
single-strand DNA on slides.
A microarray is assembled using
single-stranded DNA and silicon chips.
A microarray is assembled using a. restriction enzymes. b. agarose and nitrocellulose. c. reverse transcriptase and DNA polymerase. d. single-stranded DNA and silicon chips. e. gold beads and magnets.
single-stranded DNA and silicon chips.
Iodophors and chloramines are similar in that they are both halogen-containing compounds that __________.
slowly release their active ingredients
What types of molecules may NOT need transport proteins to be able to cross cytoplasmic membranes?
small hydrophobic molecules
A thin film of microorganisms on a slide is called a __________.
smear
Where are lipids made in the cell?
smooth endoplasmic reticulum (ER)
The experiments conducted by John T. Needham using infusions were interpreted as supporting the theory of
spontaneous generation.
Measles viruses are capable of inactivating host defenses by
suppressing the immune system
Measles viruses are capable of inactivating host defenses by producing leukocidins. producing superantigens. destroying complement proteins. suppressing the immune system.
suppressing the immune system
Which is the function of reverse transcriptase?
synthesizes DNA from an RNA template.
The detection of DNA by FISH makes use of a. DNA polymerase and DNA ligase. b. synthetic DNAs and fluorescent tags. c. restriction fragments. d. compressed air and gold beads. e. reverse transcriptase and DNA polymerase.
synthetic DNAs and fluorescent tags
Probes used for detecting genetic sequences are frequently composed of
synthetic nucleic acids and labeled conjugates, such as fluorescent dyes
Probes used for detecting genetic sequences are frequently composed of a. silicon chips. b. restriction enzymes. c. plasmids with a marker sequence. d. gold beads coated with DNA. e. synthetic nucleic acids and labeled conjugates, such as fluorescent dyes.
synthetic nucleic acids and labeled conjugates, such as fluorescent dyes.
Probes used for detecting genetic sequences are frequently composed of
synthetic nucleic acids and radioactive chemicals.
The onset of AIDS will leave the patient open to a secondary, opportunistic infection. All of the following are associated with opportunistic infection of AIDS patients EXCEPT which one?
syphilis due to Treponema pallidum infection
DNA fingerprinting produces a unique banding pattern of DNA fragments for comparison with other DNA samples.
t
Reverse transcriptase synthesizes a DNA molecule from an RNA template. 18)
t
Southern blotting is a technique that can be used to identify microbes that cannot be cultured. 21)
t
The goals of recombinant DNA technology include production of new organisms with useful combinations of traits. 20)
t
Under ideal conditions, the number of DNA molecules produced during PCR increases exponentially.
t
Which of the following is involved in bringing amino acids to the ribosomes?
tRNA
Which of the following activities can be shown to increase resistance among microbial populations?
taking antibacterial drugs for viral infections
The first and second lines of defense are non-specific because these defenses ________.
target any type of pathogens
Which of the following substances is present only in Gram positive cell walls?
teichoic acid
Antibodies from cellular immune responses are used in
the classical pathway.
Opsonization is
the coating of a pathogen by complement to facilitate phagocytosis.
Saliva contains relatively few microbes compared to other body sites, because __________. the concentration of lipids limits their growth the temperature of saliva does not support microbial growth the concentration of antimicrobial enzymes limits their growth the pH is too low
the concentration of antimicrobial enzymes limits their growth
Which of the following steps in the folic acid synthesis pathway is specifically inhibited by sulfonamides?
the conversion of PABA to dihydrofolic acid
Which of the following pathways is specifically inhibited by trimethoprim?
the conversion of dihydrofolic acid to tetrahydrofolic acid
During an oxidation reaction,
the donor molecule loses an electron and becomes oxidized.
What is the therapeutic index?
the drug dose the patient can tolerate divided by the effective dose
When a patient is treated with antibiotics, __________. mutations occur in all of the bacterial cells sensitive bacterial cells multiply uncontrollably the drug will kill or inhibit the growth of all of the sensitive bacterial cells the drug will kill or inhibit the growth of all of the resistant bacterial cells mutations will occur in the sensitive bacterial cells, but not in the resistant bacterial cells
the drug will kill or inhibit the growth of all of the sensitive bacterial cells
Microwaves do not kill organisms directly but kill by ________.
the heat they generate in a product
During the early 20th century, pandemics typically took months to years to span the globe, while the 2009 H1N1 swine flu spread globally within weeks and had affected most countries within 6 months. This difference in the rate of spread is mainly due to__________. more human contact with wild and domestic animals worldwide. the increased virulence of the pathogens. the increased volume and speed of global transportation. the emergence of antibiotic resistance.
the increased volume and speed of global transportation.
Emigration is
the migration of phagocytes through blood vessels to the site of tissue damage.
Response to specific pathogens that can improve with subsequent exposure is
the third line of defense.
All of the following pieces of information are conveyed by the name of a restriction enzyme except
the type of cut it makes
A northern blot differs from a Southern blot in
the type of nucleic acid being isolated.
Which of the following is the best definition of biotechnology?
the use of microorganism's to produce useful products
What additional information would you request from those who survived the disease?
their height and whether or not the misters were on when they shopped the produce aisle
The toxicity of a given drug is expressed as the ________.
therapeutic index
Ted heats some food just to boiling, and stores some of it immediately in a container which he places in the refrigerator. A week later he takes the food out and finds it has spoiled. The microbes responsible are probably
thermoduric
It is inappropriate to prescribe antibacterial agents to treat colds or flu because
these diseases are caused by viruses.
Although blunt-ended DNA fragments are more difficult to join back together than are sticky ends, blunt ends have an advantage in that __________.
they can be recombined with blunt fragments produced by different restriction enzymes
Microbiologists study parasitic worms because
they cause diseases that are diagnosed by finding microscopic eggs in clinical specimens
Protoplasts are valuable in techniques used to insert DNA into cells because
they have no cell wall to interfere with the entry of DNA into the cell
The ingestion of a large number of Vibrio cholerae cells is necessary for infection. Why is such a large concentration of bacteria needed? to ensure enough survive the low pH in the stomach to establish infection to ensure enough bacteria survive the enzymes in our mouth because a large number of bacteria are required to overcome the specificity of our immune system because they must compete with bacteria in our intestines
to ensure enough survive the low pH in the stomach to establish infection
What is the purpose of fermentation?
to regenerate NAD+ from NADH
Among the recommendations from the Centers for Disease Control and Prevention to limit the development of antibiotic resistance are __________. to treat with the oldest, effective antimicrobial to treat with broad spectrum drugs to stop taking the antimicrobial as soon as symptoms disappear to treat with the newest, effective antimicrobial
to treat with the oldest, effective antimicrobial
Modified corn strains that produce an insect toxin from a bacterial gene are an example of a. vectors. b. gene therapy. c. transgender organisms. d. protoplasts. e. transgenic organisms
transgenic organisms
If you needed to look at the fine details of the interior of a virus, which microscope would you use?
transmission electron microscope
Integral proteins are mostly involved in
transport function.
Which of the following situations might cause normal microbiota to become opportunistic pathogens?
treatment of a cancer patient with radiation
A person with type B blood can receive blood from individuals with which of the following blood types?
type B or O
How should you describe this skin reaction to the bee sting?
type I hypersensitivity reaction
Hypersensitivity pneumonitis is an example of which of the following types of hypersensitivity?
type III
An agricultural worker experiences difficulty breathing which becomes progressively worse. Tests show inflammation and damage of the lung tissue, but IgE antibodies and granulocytes are in the normal ranges. With which disorder of the immune system are these signs and symptoms consistent?
type III (immune complex-mediated) hypersensitivity
A northern blot differs from a Southern blot in the
type of nucleic acid being isolated.
A northern blot differs from a Southern blot in the a. size of the genetic sequences involved. b. type of probe used. c. number of genetic sequences detected. d. type of nucleic acid being isolated. e. presence or absence of a nitrocellulose membrane.
type of nucleic acid being isolated.
The most important rickettsial diseases in humans include __________. Q fever Lyme disease typhus fever West Nile fever
typhus fever
The dairy creamer used in restaurants is usually treated by
ultra-high-temperature pasteurization.
Which of the following is NOT an example of ionizing radiation?
ultraviolet light
Which of the following types of radiation is nonionizing and has the shortest wavelength?
ultraviolet light
Who was the most likely source of infection for this child?
uncle
If a T cell recognizes MHC in conjunction with autoantigens, it will either __________ or differentiate to become a regulatory T cell.
undergo apoptosis
A Deadly Carrier In 1937, a man employed to lay water pipes was found to be the source of a severe epidemic of typhoid fever. The man, an asymptomatic carrier of Salmonella enterica serotype Typhi, the bacterium that causes typhoid, habitually urinated at his job site. In the process, he contaminated the town's water supply with bacteria from his bladder. Over 300 cases of typhoid fever developed, and 43 people died before the man was identified as the carrier. How is this carrier identified?
urine culture
Which of the following procedures is currently the standard test used in the United States for evaluating the efficiency of antiseptics and disinfectants?
use-dilution test
The common methods to control the spread of West Nile virus include __________. using insect repellents wearing loose-fitting clothes when outside a vaccine for humans providing water in yards for birds to drink
using insect repellents
Nucleic acid molecules used to deliver new genes to cells are called (plasmids/vectors/clones).
vectors
Small circular DNA autonomously replicating molecules with several restriction sites and a "marker" to trace their location are commonly called a. phages. b. vehicles. c. arrays. d. vectors. e. clones.
vectors
What is the name of genetic tools that can deliver genes into a cells?
vectors
Which of the following is most susceptible to antimicrobial agents?
vegetative bacteria
Which of the following is most susceptible to antimicrobial agents?
vegetative bacteria Vegetative bacteria are active metabolically and will typically be more susceptible to antimicrobial control methods.
A patient contracted a disease just by being in the same room with an infected individual for an extended period of time. Which of the following modes of disease transmission is most applicable in this situation?
vehicle transmission
Jerica takes her young son to the pediatrician for regular childhood immunizations. While there, they wait in a room full of sneezing, sniffling, coughing youngsters. Despite making sure that her son stays at least six feet (two meters) from the other children and doesn't touch any play toys in the waiting room, microbes could still spread to her son by
vehicle transmission.
TRANSFORMATION PICTURES
vertical picture with recipient cell and DNA fragments going into a cell
It is difficult to attain good selective toxicity with antiviral drugs because of the fact that __________. viruses can hide in an envelope from the host cell viruses are not living organisms viruses are not cells viruses require host cells to replicate themselves
viruses require host cells to replicate themselves
A patient is brought to the hospital with severe gastrointestinal distress, including cramps, dehydration and diarrhea. Which of the following symptoms would indicate that the pathogen is Vibrio cholerae? occasional diarrhea but no blood in the stool frequent vomiting voluminous watery diarrhea bloody, foul smelling diarrhea
voluminous watery diarrhea
Rickettsia are obligate intracellular parasites that are transmitted by arthropods. In which of the following places would you most likely find the parasites living in the host organism during the course of infection? within the blood plasma on the surface of heart cells on the outer surface of the skin within macrophages
within macrophages
A positively charged sodium ion
would require the use of integral protein channels to pass through a cell membrane.
In this application, human genes are inserted into animals to produce cells, tissues, or organs that are then introduced into the human body, reducing the likelihood of rejection. It is a one-word answer and spelling matters.
xenotransplant
In this application, human genes are inserted into animals to produce cells, tissues, or organs that are then introduced into the human body, reducing the likelihood of rejection. It is a one-word answer and spelling matters.
xenotransplantation
Drug-resistant populations of microbes arise when ________.
xposure to drugs selectively kills sensitive cells, allowing overgrowth of resistant cells
Which of the following classifications would best describe Candida albicans?
yeast