Deck 7: Fundamentals of Microbial Growth

Question 1

Which of the following is not an environmental factor that would affect the growth of E. coli?

A) temperature
B) antibiotics produced from other bacterial species
C) concentration of other bacteria
D) availability of nutrients
E) generation time of E. coli

Answer 1

generation time of E. coli

Question 2

Which temperature group are most pathogens associated with?

A) psychrotrophs
B) thermophiles
C) extreme thermophiles
D) psychrophiles
E) mesophiles

Answer 2

mesophiles

Question 3

Which of the following terms refers to microbes that thrive in high- salt environments?

A) psychrophiles
B) acidophiles
C) barophiles
D) neutralophiles
E) halophiles

Answer 3

halophiles

Question 4

Mycobacterium tuberculosis are grown for 80 hours. During that time, they go through four generations of growth. What is the generation time?

A) 60 minutes
B) 40 hours
C) 10 hours
D) 20 hours
E) 20 minutes

Question 5

Staphylococcus aureus tolerates higher solute concentrations but doesn't grow especially well in them. Therefore, it is called a

A) mesophilic neutralophile.
B) facultative halophile.
C) halo- alkaliphile.
D) halo- thermophile.
E) halo- psychrophile.

Question 6

Which group of microbes prefers using oxygen but can survive without it?

A) aerotolerant anaerobe
B) obligate aerobe
C) microaerophile
D) obligate anaerobe
E) facultative anaerobe

Question 7

How do halophiles combat osmotic stress?

A) They enrich their plasma membrane with basic compounds to attract OH- ions to their cell surface.
B) They use proton pumps to export excess protons from the cytoplasm.
C) They keep a high concentration of organic materials and ions in their cytoplasm.
D) They use plasma membrane lipids that are highly branched and saturated.
E) They build special monolayer plasma membranes.

Question 8

Microbes that primarily infect the lungs are likely to be classified as which of the following?

A) obligate anaerobe
B) obligate aerobe
C) aerotolerant anaerobe
D) microaerophile
E) facultative anaerobe

Question 9

Which of the following pH classifications make up most of the pathogens we know today?

A) psychrophiles
B) barophiles
C) acidophiles
D) neutralophiles
E) alkaliphiles

Question 10

Which of the following pH classifications would be able to grow in a pickle jar with vinegar?

A) alkaliphiles
B) psychrophiles
C) acidophiles
D) neutralophiles
E) barophiles

Question 11

In which growth phase do bacteria adjust to their environment and grow little, if any?

A) lag phase
B) acculturation phase
C) log phase
D) stationary phase
E) habituation phase

Question 12

The necessary substances that a cell can't make on its own are called

A) amino acids.
B) nitrogenous bases.
C) growth factors.
D) carbohydrates.
E) vitamins.

Question 13

Which of the following methods do alkaliphiles use to survive in their environments?

A) enrich their plasma membrane with acidic compounds to attract H+ ions to their cell surface
B) enrich their plasma membrane with basic compounds to attract OH- ions to their cell surface
C) build special monolayer plasma membranes
D) use proton pumps to export excess protons from the cytoplasm
E) use plasma membrane lipids that are highly branched and saturated

Question 14

Which term represents the temperature that bacteria grow the fastest at?

A) human body temperature
B) optimal
C) minimum
D) hospitable
E) maximum

Question 15

Extreme thermophiles that live near thermal vents must have all of the following adaptations except

A) plasma membrane lipids that are highly unsaturated.
B) they must also be barophiles.
C) plasma membrane lipids that are highly branched and saturated.
D) specialized chaperone proteins.
E) proteins that resist thermal denaturing.

Question 16

Nutrients that a cell needs to build new cells and make up a bulk of a cell's dry weight are called

A) small nutrients.
B) trace nutrients.
C) micronutrients.
D) tiny nutrients.
E) essential nutrients.

Question 17

Which of the following terms refers to bacteria reproducing asexually by dividing the cell in half and resulting in two daughter cells?

A) budding
B) binary fission
C) sporulation
D) hypha
E) conidia

Question 18

Which of the following types of organisms is associated with foodborne illness?

A) psychrotrophs
B) extreme thermophiles
C) mesophiles
D) psychrophiles
E) thermophiles

Question 19

In which growth phase do bacteria grow exponentially?

A) log phase
B) acculturation phase
C) lag phase
D) stationary phase
E) habituation phase

Question 20

In which growth phase do bacteria produce antibiotics and endospores?

A) death phase
B) log phase
C) lag phase
D) acculturation phase
E) stationary phase

Question 21

What is the purpose of the streak plate technique?

A) to obtain a pure culture from a mixed or unknown source
B) to determine the concentration of a microbial sample
C) to identify the correct concentration of nutrients needed for optimal bacterial growth
D) to identify the best temperature for growing a particular microbe
E) to ascertain the age of a particular culture

Question 22

A chemical used to control microbial growth on inanimate objects is called a(n)

A) antiseptic.
B) microbiocidal.
C) antibacterial agent.
D) microbiostatic.
E) disinfectant.

Question 23

Low- level disinfectants are sufficient to remove microbes from which of the following equipment tiers?

A) semicritical
B) noncritical
C) nonessential
D) vital
E) non- vital

Question 24

Which of the following microbes is not correctly matched to an acceptable control method?

A) Mycobacteria: hydrogen peroxide
B) Prions: chlorine treatment
C) Enveloped virus: glutaraldehyde- based detergents
D) Endospore: autoclaving
E) Protozoan: boiling water

Question 25

The minimum temperature needed to kill all microbes in a sample within ten minutes is called the

A) thermal death point.
B) thermal death time.
C) essential reduction point.
D) critical death time.
E) decimal reduction time.

Question 26

Which type of media has ingredients that foster the growth of certain bacteria while suppressing the growth of others?

A) complex
B) defined
C) synthetic
D) differential
E) selective

Question 27

Which of the following factors does not affect the efficiency of a germicide?

A) how the object is used
B) the presence of excessive organic substances like blood, soil, or fecal matter
C) what infectious agents are most likely present
D) the presence of excessive inorganic substances like minerals and salts in hard water
E) the number of microbes to be killed

Question 28

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.

Question 29

Which of the following is an indirect cell- counting method?

A) microscopic count
B) viable plate count
C) Coulter counter
D) flow cytometer
E) turbidity measurement

Question 30

When would a microbiologist want to use broth media?

A) when growing large batches of microbes
B) when isolating colonies
C) when observing specific culture characteristics
D) when testing for motility
E) when performing the streak plate isolation technique

Question 31

Which of the following could result in the wrong patient diagnosis and improper treatment?

A) carefully sampling only the site in question without touching other body structures or surface sites
B) using a cotton tip swap to collect a suspected pathogen
C) wearing gloves
D) proper hand washing before and after specimen collection
E) quickly sealing samples in containers

Question 32

Which type of organism gets energy from breaking down nutrients and uses CO₂ as a carbon source?

A) lithotroph
B) chemoautotroph
C) photoheterotroph
D) photoautotroph
E) chemoheterotroph

Question 33

Which of the following methods would surgical staff use to disinfect surfaces in operating rooms?

A) non- ionizing radiation
B) autoclaving
C) gamma ray radiation
D) x- ray radiation
E) ionizing radiation

Question 34

When would a microbiologist use thioglycolate?

A) when making complex media
B) when making defined media
C) when storing differential plates
D) when storing plates anaerobically
E) when storing selective plates

Question 35

Which of the following cell- counting methods is capable of differentiating between living and dead cells?

A) microscopic count
B) flow cytometer
C) dry weight
D) turbidity measurement
E) Coulter counter

Question 36

Many microbes have evolved ways to detoxify reactive oxygen species so that they can safely use oxygen in their metabolism.

Question 37

The Simmons citrate test and triple sugar iron (TSI) media are common examples of slants.

Question 38

Chemoautotrophs use an inorganic carbon source.

Question 39

Bacterial spore formation is a type of sexual reproduction.

Question 40

Which type of organism would a microbiologist grow on defined media?

A) fastidious organisms
B) organisms with complex growth requirements
C) pathogens from clinical samples
D) certain autotrophs
E) a broad collection of heterotrophs

Question 41

Disinfectants are applied to living tissue such as skin.

Question 42

Name one benefit and one challenge to using genetic methods to identify microbes.

Question 43

Phenols are commonly used in hospitals to sterilize critical equipment.

Question 44

What are two benefits to a germicide that quickly evaporates compared to a germicide that leaves a residue behind?

Question 45

Name three differences between how microbes grow in a closed pure batch system as compared to in nature.

Question 46

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