Micro Biology Exam 2

The MIC of the drug against the microbe is ______.

6.4 μg/ml

The genes of which microorganism(s) are arranged as operons?

Bacteria

The common products of fermentation include ______.

Carbon dioxide, Organic acids, and alcohol

Which is NOT an advantage of fermentation to microbial survival and growth?

Promotes growth in oxygen-rich areas of the host

Which phrase best describes the process of fermentation?

The partial oxidation of glucose

A phage is a virus that infects ______.

bacteria

Which of the following is an excellent target for selective drug toxicity?

bacteria cell wall

An organism that lacks an electron transport chain must derive its energy from ______.

fermentation

Glycolysis rates increase tremendously during _____.

fermentation

Drug failure may be attributed to an infection caused by more than one type of microbe, the inability of the drug to diffuse to the correct location in the body, or to the presence of ________________ bacteria.

resistant

The type of fermentation that produces ethyl alcohol is called 1.(Blank)fermentation, while the type that produces lactic acid is called 2. (Blank) fermentation.

1. Alcohol, and 2. Acid

Which describes a plasmid?

A small circular piece of DNA that replicates its nonessential genes independently of the chromosome.

____________ chemotherapy is the use of chemotherapeutic drugs to control infection and diseases caused by many types of microorganisms.

Antimicrobial

Which genus of fungi is NOT a major source of antibiotics?

Aspergillus

If a particular antimicrobial drug is effective against a variety of different bacteria, it would have a(n) ____________ spectrum.

Broad

A region of some bacterial chromosomes that includes both a set of short repeated sequences and spacer DNA with remnants of bacteriophage and plasmid DNA is called . (Use abbreviation)

CRISPR

Bacteria and archaea store remnants of invading bacteriophage or plasmids at a site called ______.

CRISPR

What type of bacterial cell can be transformed by DNA in the environment?

Competent cell

_______ involves the use of a connecting bridge, _______ requires a bacterial virus vector, and ______ entails transfer of naked DNA.

Conjugation; transduction; transformation

An important means for bacteria to directly transfer resistance plasmids from one cell to another is through the process of

Conjunction

A(n) ______ cell has a separate fertility plasmid, whereas a(n) _____ cell has the F factor incorporated into its chromosome.

F+; Hfr

Which of the following does not require oxygen for the further breakdown of pyruvic acid.

Facultative anaerobes

True or false: Anaerobic respiration and aerobic respiration are the same thing.

False

True or false: Bacterial conjugation is sexual reproduction

False

True or false: In fermentative metabolism, pyruvate is reduced into pyruvic acid.

False

True or false: It is essential to perform an antimicrobial susceptibility test for all infectious agents.

False

What pathway can be used by facultative anaerobes if oxygen is not readily available?

Fermentation

_________ transduction transfers random pieces of host cell DNA, whereas ________ transduction transfers pieces next to the prophage insertion site in the bacterial chromosome.

Generalized; specialized

Regardless of lactose levels, the lac operon remains in the "off" position if what nutrient(s) is present?

Glucose

In CRISPR technology, the targeted gene is recognized by a molecule called

Guide RNA

For which of the following reasons would antimicrobial susceptibility testing be performed?

If the pathogen commonly shows resistance to the antibiotic

Which strategy is used to prevent colonization of biomaterials that are susceptible to biofilm contamination?

Impregnation of biomaterials with antibiotics prior to insertion

Which of the following is NOT a general mechanism of antimicrobial drug actions?

Inhibiting electron transport systems

Which of the following are general mechanisms of antimicrobial drug actions?

Inhibiting nucleic acid structure or function, Inhibiting cell wall synthesis, Inhibiting protein synthesis, Interference of cell membrane structure and function

During fermentation, which electron carrier is made available to reenter glycolysis so that ATP production can continue in the absence of oxygen?

NAD

As a result of fermentation, ______ are produced that are recycled to enter ______.

NADs; glycolysis

Bacterial and archaeal genes are arranged into ________

Operons

Which of these antibiotics would be a poor choice to treat an infection caused by Staphylococcus aureus?

Penicillin G

Transposons are linked to which of the following in bacteria?

Phenotypic changes in colonies, Intermicrobial transfer of drug resistance, and Replacement of damaged DNA

Donor and recipient bacterial cells are connected by a(n) ___________ during conjugation.

Pilus

Which of the following statements are correct regarding the Kirby-Bauer data in the table?

Polymyxin is not a good choice, as it is intermediate in effectiveness and Tetracycline is extremely effective against S. aureus and would be a good choice.

What is commonly shared between bacteria through the process of conjugation?

Resistance plasmids and Genes for virulence factors

Examine the data in the table regarding the susceptibility of Staphylococcus aureus to erythromycin. Which of the following statements is correct?

S. aureus responds in an intermediate manner and erythromycin would not be effective in treating this infection.

Which type of transduction involves temperate phages that incorporate their genome into the bacterial host chromosome before carrying pieces to another host cell?

Specialized transduction

The two major bacterial sources of antibiotics are the genera __________ and _____________- .

Streptomyces and Bacillus

Which oxidized compound(s) can be used as a final electron acceptor in anaerobic respiration?

Sulfate (SO42-), Nitrate (NO3-), and Carbonate (CO33-)

Two antibiotics are being considered for a patient. The causative microbe is susceptible to both antibiotics. One drug has a therapeutic index of 1.1 and the other has a therapeutic index of 10. Which is the best choice?

The drug with the therapeutic index of 10

How do an Hfr cell and an F+ cell differ?

The plasmid is integrated into the chromosome of an Hfr cell but not in an F+ cell.

Which type of horizontal gene transfer has been linked to the virulence of bacteria such as Clostridium, Streptococcus pyogenes, and Corynebacterium diphtheriae?

Transduction

________ are DNA sequences that can switch sites in a genome and lead to changes in the genotype.

Transposons

What is drug resistance?

When microbes begin to tolerate an antimicrobial agent at a level which would normally be inhibitory

Starting with pyruvic acid, which two types of fermentation can occur?

acidic fermentation, and alcoholic fermentation

The presence of a CRISPR region in a bacterial chromosome is a(n) _____ to the host because ______.

advantage; it allows the microbe to keep a record of previous phage invasions

Which type of chemotherapy involves the use of chemotherapeutic drugs to control infection and diseases caused by many types of microorganisms?

antimicrobial chemotherapy

A(n) ______ is a bacterial virus involved in _______, a means of horizontal gene transfer.

bacteriophage; transduction

The active part of the penicillin and cephalosporin structure is the ______ ring.

beta-lactam

Complex polysaccharides can be used as a source of carbon and energy by ______.

breaking them down into their component sugars

An antimicrobial drug that is effective against a variety of different bacteria would have a ______ spectrum.

broad

Phase variation occurs when Streptococcus pneumoniae produce a ________________

capsule

Which oxidized compound can be used as a final electron acceptor in anaerobic respiration?

carbonate (CO33-), sulfate (SO42-), and nitrate (NO3-)

Penicillin derivatives were developed that overcame the limitations of the original penicillin. These derivatives resulted from ______.

chemical modification

In this Kirby Bauer test with E. coli, the bacterium is resistant to ______.

chloramphenicol and oxytetracycline

A bacterial cell that can accept soluble DNA from the surrounding environment is described as

competent

Besides glucose, which of the following compounds can be used as a source of energy and building blocks?

complex polysaccharides, fats, and proteins

The binding of lactose to the lac repressor results in ______.

conformational change to the lac repressor

A pilus connects two bacterial cells to facilitate the transfer of genetic material during the process of

conjugation

In bacteria, horizontal gene transmission through a pilus is called

conjugation

Which organisms carry out fermentation?

facultative anaerobes, and aerotolerant anaerobes

In CRISPR, the gene sequence to be altered is specified by a _____ RNA.

guide

n CRISPR, the gene sequence to be altered is specified by a _____ RNA.

guide

When considering antibiotics for patient use, it is best to use a drug with a _____ therapeutic index.

high

Peptidoglycan in the bacterial cell envelope is an ideal target for antibiotics because ______.

human cells do not have peptidoglycan, and cell wall synthesis inhibitors are selectively toxic to bacteria

Penicillins exhibit low toxicity for human cells because ______.

human cells do not synthesize peptidoglycan, the target of penicillins

In the presence of glucose and lactose, the lac operon will be _____.

inactive

A CRISPR region in a bacterial chromosome offers an advantage to the host because it allows the ______.

microbe to keep a record of previous attacks

Biofilm infections are most likely to be found in or on which of the following?

middle ear and urinary catheter

A ______-spectrum drug is effective against a limited array of microbe types. Multiple choice question.

narrow

If an antimicrobial drug is only effective against gram-negative bacteria, it has a(n) ______ spectrum.

narrow

In the absence of lactose, the lac repressor binds to the ______________

operator

The lac repressor binds to the ______ in the absence of lactose.

operator

An organism will gets its energy from fermentation when ______.

oxygen is absent from its environment and it does not have an electron transport chain

The beta-lactam ring is the active part of ______ and cephalosporin structure.

penicillin

Which term refers to bacteria that slow or stop their metabolism so that they cannot be harmed by an antibiotic?

persisters

The ability of Neisseria gonorrhoeae strains to produce attachment fimbriae is an example of ______.

phase variation

The process of bacteria turning on or off a group of genes that changes its phenotype is called ______________ __________________

phase variation

Phase variation is a type of ________ variation.

phenotypic

In bacteria and archaea, CRISPR areas of the genome are a storage site for ______.

pieces of DNA from phage or plasmids

Donor and recipient bacterial cells are connected by a(n) _____________ during conjugation.

pilus

A small circular segment of DNA found in the cytoplasm of bacteria that is capable of independent replication and usually contains nonessential genes is called a(n)

plasmid

A CRISPR region of a bacterial chromosome is comprised of ______.

spacer DNA with pieces of bacteriophage or plasmid and short sequences repeated many times

Binding of lactose to the lac repressor results in transcription of the ______.

structural genes

In the CRISPR technique, a guide RNA ______.

targets the gene sequence to be modified

The production of toxins in some virulent strains of bacteria has been linked to bacteriophage genes that have been transferred by _____________.

transduction

Jumping genes", or , are gene sequences that can lead to changes in genotype within a cell or between cells.

transposons

What has been linked to changing morphology in bacteria, the intermicrobial transfer of drug resistance, and the repair of damaged DNA in bacteria?

transposons

True or false: One reason that antibiotic treatment failure occurs is because the drug could not diffuse into the infected body part

true

An excellent cellular structure that can be a target for selective drug toxicity is the bacterial cell

wall

Under which circumstance might a microbe be intrinsically resistant to an antibiotic?

when the microbe produces the antibiotic