Chapter 7

Bacterial spore formation is a type of sexual reproduction. ANSWER: True False

False

Chemoautotrophs use an inorganic carbon source. ANSWER: True False

False

Disinfectants are applied to living tissue such as skin. ANSWER: True False

False

The pour plate method is capable of detecting an exact cell number in the plated sample. ANSWER: True False

False

You are a manufacturer of polypropylene hypodermic syringes. Which of the following methods would be best for ensuring sterility of this heat-sensitive material? ANSWER: Pasteurization Non-ionizing radiation Ionizing radiation Autoclave

Ionizing radiation

Helicobacter pylori is a bacterial pathogen known to cause duodenal and gastric ulcers in humans. One of the cornerstones for treatment of H. pylori is a proton pump inhibitor. Which of the following terms best describes H. pylori? ANSWER: Psychrophilic barophile Thermophilic alkaliphile Extreme thermophilic neutralophile Mesophilic acidophile

Mesophilic acidophile

You suspect that your patient has a urinary tract infection caused by Proteus vulgaris, a motile bacterium with peritrichous flagella. Which of the following physical states of media is best for observing motility of this pathogen once isolated? ANSWER: Solid slant Broth media Solid plate Semisolid deep

Semisolid deep

Which of the following terms refers to bacteria reproducing asexually by dividing the cell in half and resulting in two daughter cells? ANSWER: conidia hypha budding sporulation binary fission

binary fission

Which type of organism would a microbiologist grow on defined media? ANSWER: a broad collection of heterotrophs certain autotrophs fastidious organisms organisms with complex growth requirements pathogens from clinical samples

certain autotrophs

Which type of organism gets energy from breaking down nutrients and uses CO2 as a carbon source? ANSWER: chemoheterotroph photoautotroph photoheterotroph lithotroph chemoautotroph

chemoautotroph

Which of the following cell-counting methods is capable of differentiating between living and dead cells? ANSWER: flow cytometer dry weight Coulter counter turbidity measurement microscopic count

flow cytometer

When would a microbiologist use thioglycolate? ANSWER: when making defined media when storing plates anaerobically when storing selective plates when storing differential plates when making complex media

when storing plates anaerobically

Mycobacterium tuberculosis are grown for 80 hours. During that time, they go through four generations of growth. What is the generation time? ANSWER: 10 hours 60 minutes 40 hours 20 hours 20 minutes

20 hours

Staphylococcus aureus is grown in heart-infusion broth at 37°C. If you start exponential phase with 100 cells, and after 90 minutes you have 800 cells, what is the generation time for S. aureus? ANSWER: 30.00 minutes 0.11 minutes 11.25 minutes 0.03 minutes

30.00 minutes

How do halophiles combat osmotic stress? ANSWER: They use plasma membrane lipids that are highly branched and saturated. They use proton pumps to export excess protons from the cytoplasm. They build special monolayer plasma membranes. They enrich their plasma membrane with basic compounds to attract OH- ions to their cell surface. They keep a high concentration of organic materials and ions in their cytoplasm.

They keep a high concentration of organic materials and ions in their cytoplasm.

Which of the following pH classifications would be able to grow in a pickle jar with vinegar? ANSWER: acidophiles psychrophiles neutralophiles barophiles alkaliphiles

acidophiles

A chemical used to control microbial growth on inanimate objects is called a(n) ANSWER: microbiostatic. microbiocidal. antiseptic. disinfectant. antibacterial agent.

disinfectant.

Which of the following methods do alkaliphiles use to survive in their environments? ANSWER: use plasma membrane lipids that are highly branched and saturated enrich their plasma membrane with basic compounds to attract OH- ions to their cell surface enrich their plasma membrane with acidic compounds to attract H+ ions to their cell surface build special monolayer plasma membranes use proton pumps to export excess protons from the cytoplasm

enrich their plasma membrane with acidic compounds to attract H+ ions to their cell surface

Nutrients that a cell needs to build new cells and make up a bulk of a cell's dry weight are called ANSWER: micronutrients. small nutrients. tiny nutrients. essential nutrients. trace nutrients.

essential nutrients.

Which of the following is not an environmental factor that would affect the growth of E. coli? ANSWER: availability of nutrients temperature generation time of E. coli concentration of other bacteria antibiotics produced from other bacterial species

generation time of E. coli

The necessary substances that a cell can't make on its own are called ANSWER: carbohydrates. vitamins. amino acids. growth factors. nitrogenous bases.

growth factors.

Which of the following terms refers to microbes that thrive in high-salt environments? ANSWER: acidophiles halophiles barophiles psychrophiles neutralophiles

halophiles

In which growth phase do bacteria adjust to their environment and grow little, if any? ANSWER: log phase acculturation phase stationary phase lag phase habituation phase

lag phase

In which growth phase do bacteria grow exponentially? ANSWER: stationary phase acculturation phase habituation phase lag phase log phase

log phase

Which of the following methods would surgical staff use to disinfect surfaces in operating rooms? ANSWER: gamma ray radiation x-ray radiation autoclaving ionizing radiation non-ionizing radiation

non-ionizing radiation

Low-level disinfectants are sufficient to remove microbes from which of the following equipment tiers? ANSWER: nonessential semicritical non-vital vital noncritical

noncritical

Microbes that primarily infect the lungs are likely to be classified as which of the following? ANSWER: aerotolerant anaerobe obligate anaerobe facultative anaerobe microaerophile obligate aerobe

obligate aerobe

Which term represents the temperature that bacteria grow the fastest at? ANSWER: optimal hospitable maximum human body temperature minimum

optimal

Extreme thermophiles that live near thermal vents must have all of the following adaptations except ANSWER: proteins that resist thermal denaturing. specialized chaperone proteins. plasma membrane lipids that are highly branched and saturated. plasma membrane lipids that are highly unsaturated. they must also be barophiles.

plasma membrane lipids that are highly unsaturated.

In which growth phase do bacteria produce antibiotics and endospores? ANSWER: death phase stationary phase log phase acculturation phase lag phase

stationary phase

The minimum temperature needed to kill all microbes in a sample within ten minutes is called the ANSWER: critical death time. essential reduction point. thermal death time. decimal reduction time. thermal death point.

thermal death point.

Which of the following is an indirect cell-counting method? ANSWER: viable plate count flow cytometer microscopic count Coulter counter turbidity measurement

turbidity measurement

The following table shows the generation time for an Escherichia coli culture grown at various incubation temperatures. Table 1. Incubation Temperature and Corresponding Generation Times of E. coli Table 1 shows the generation time for Escherichia coli at various temperatures. At 5℃ and 60℃ , the culture does not grow. At 7℃, the generation time is 40 minutes, at 37℃, the generation time is 20 minutes, at 42℃ , the generation time is 35 minutes. According to the table above, the optimal growth temperature for E. coli is: ANSWER: 7°C 42°C 37°C 60°C

37°C

Which of the following strategies can be used to treat drinking water, ensuring that it is not contaminated with protozoans such as Cryptosporidium parvum? To be marked correct, you'll need to select all applicable statements, as there may be more than one correct answer. ANSWER: Ozone treatment Filtration Exposure to ultraviolet light Addition of glutaraldehyde-based detergent

Ozone treatment Filtration Exposure to ultraviolet light

Which of the following microbes is not correctly matched to an acceptable control method? ANSWER: Enveloped virus: glutaraldehyde-based detergents Mycobacteria: hydrogen peroxide Prions: chlorine treatment Protozoan: boiling water Endospore: autoclaving

Prions: chlorine treatment

Which group of microbes prefers using oxygen but can survive without it? ANSWER: obligate anaerobe aerotolerant anaerobe obligate aerobe microaerophile facultative anaerobe

facultative anaerobe

Staphylococcus aureus tolerates higher solute concentrations but doesn't grow especially well in them. Therefore, it is called a ANSWER: halo-thermophile. halo-psychrophile. facultative halophile. halo-alkaliphile. mesophilic neutralophile.

facultative halophile.

Which temperature group are most pathogens associated with? ANSWER: thermophiles mesophiles extreme thermophiles psychrotrophs psychrophiles

mesophiles

Which of the following pH classifications make up most of the pathogens we know today? ANSWER: barophiles acidophiles neutralophiles psychrophiles alkaliphiles

neutralophiles

Which of the following types of organisms is associated with foodborne illness? ANSWER: psychrotrophs thermophiles psychrophiles extreme thermophiles mesophiles

psychrotrophs

Which type of media has ingredients that foster the growth of certain bacteria while suppressing the growth of others? ANSWER: differential synthetic complex selective defined

selective

What is the purpose of the streak plate technique? ANSWER: to ascertain the age of a particular culture to obtain a pure culture from a mixed or unknown source to identify the correct concentration of nutrients needed for optimal bacterial growth to determine the concentration of a microbial sample to identify the best temperature for growing a particular microbe

to obtain a pure culture from a mixed or unknown source

Which of the following could result in the wrong patient diagnosis and improper treatment? ANSWER: using a cotton tip swap to collect a suspected pathogen proper hand washing before and after specimen collection quickly sealing samples in containers wearing gloves carefully sampling only the site in question without touching other body structures or surface sites

using a cotton tip swap to collect a suspected pathogen

When would a microbiologist want to use broth media? ANSWER: when testing for motility when observing specific culture characteristics when isolating colonies when growing large batches of microbes when performing the streak plate isolation technique

when growing large batches of microbes

Which of the following is a key distinguishing characteristic between budding and binary fission? ANSWER: Budding is a much more common mechanism of bacterial reproduction than binary fission is. You will recall that budding is an example of sexual reproduction, whereas binary fission is an example of asexual reproduction. While binary fission results in the creation of genetically identical daughter cells, budding results in daughter cells that are genetically diverse. Binary fission results in daughter cells of equal size, whereas budding is an uneven division

Binary fission results in daughter cells of equal size, whereas budding is an uneven division

Escherichia coli is characterized as a facultative anaerobe. You set up an experiment to examine the growth of Escherichia coli in three environments: a GasPak jar (0% oxygen), a candle jar (10% oxygen), and the benchtop (22% oxygen). Aside from differing oxygen levels, all other culture conditions (such as temperature and media used) were kept constant. Which of the following represents the most likely outcome of the experiment? ANSWER: E. coli will have heavy growth in the GasPak jar and moderate growth in the candle jar and the benchtop. E. coli will have heavy growth on the benchtop but moderate growth in the candle jar and the GasPak jar. E. coli will have heavy growth on the benchtop, moderate growth in the candle jar, and no growth in the GasPak jar. E. coli should grow equally in all three growth environments.

E. coli will have heavy growth on the benchtop but moderate growth in the candle jar and the GasPak jar.

In the death phase of a closed pure batch system a small number of the cells survive by adapting to the new waste-filled environment and by feeding off dead cells. ANSWER: True False

True