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Biol 251 Exam 2 unr (HW + LC Questions and Answers with
100% Complete Solutions UPDATED!!!)
Bacterial growth refers to an increase in the numbers of cells in
a bacterial culture - ANSWER True
Most bacteria reproduce by - ANSWER binary fission
What results when a single bacterium reproduces? - ANSWER
Two genetically identical daughter cells
You begin with 6 cells. How many are there after 3 rounds of
division? - ANSWER 48 cells
Which is NOT a step in bacterial cell division? - ANSWER
Disappearance of a nuclear envelope
Which step of binary fission is the reason for genetically
identical daughter cells? - ANSWER replication of bacterial
chromosome
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Chemical requirements for microbial growth include Carbon,
Nitrogen, Phosphorus, and Sulfur. Why do all cells need
Nitrogen? - ANSWER for building amino acids, proteins, and
nucleic acids
Salts and sugars work to preserve foods by creating a - ANSWER
hypertonic environment
Bacteria that can grow in the presence or absence of Oxygen
are called - ANSWER facultative anaerobes
Which microbe classification is mismatched with optimal
growth temperatures? - ANSWER thermophile --- grow at 37
degrees C
wrong bc thermo = heat loving (41-122 C)
Microbes have very narrow optimum temperature ranges.
Which of the following classifications of microbes are most
likely to cause human disease, based on their temperature
requirements? - ANSWER mesophiles
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Patients with indwelling catheters are susceptible to infections
because - ANSWER biofilms develop on catheters
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 bacteria must adjust to the nutrient content in the
new medium, synthesizing necessary amino acids, growth
factors, and enzymes
Which of the following phases of the bacterial growth curve is
matched with the CORRECT definition? - ANSWER log phase -
phase in which organisms are actively dividing and the
generation time is constant
Isolated colony on a streak plate contains millions of identical
cells all arising from one initial cell - ANSWER true
Source of nutrients in nutrient agar - ANSWER peptone and
beef extract
Biol 251 Exam 2 unr (HW + LC Questions and Answers with
100% Complete Solutions UPDATED!!!)
Bacterial growth refers to an increase in the numbers of cells in
a bacterial culture - ANSWER True
Most bacteria reproduce by - ANSWER binary fission
What results when a single bacterium reproduces? - ANSWER
Two genetically identical daughter cells
You begin with 6 cells. How many are there after 3 rounds of
division? - ANSWER 48 cells
Which is NOT a step in bacterial cell division? - ANSWER
Disappearance of a nuclear envelope
Which step of binary fission is the reason for genetically
identical daughter cells? - ANSWER replication of bacterial
chromosome
,2|Page
Chemical requirements for microbial growth include Carbon,
Nitrogen, Phosphorus, and Sulfur. Why do all cells need
Nitrogen? - ANSWER for building amino acids, proteins, and
nucleic acids
Salts and sugars work to preserve foods by creating a - ANSWER
hypertonic environment
Bacteria that can grow in the presence or absence of Oxygen
are called - ANSWER facultative anaerobes
Which microbe classification is mismatched with optimal
growth temperatures? - ANSWER thermophile --- grow at 37
degrees C
wrong bc thermo = heat loving (41-122 C)
Microbes have very narrow optimum temperature ranges.
Which of the following classifications of microbes are most
likely to cause human disease, based on their temperature
requirements? - ANSWER mesophiles
, 3|Page
Patients with indwelling catheters are susceptible to infections
because - ANSWER biofilms develop on catheters
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 bacteria must adjust to the nutrient content in the
new medium, synthesizing necessary amino acids, growth
factors, and enzymes
Which of the following phases of the bacterial growth curve is
matched with the CORRECT definition? - ANSWER log phase -
phase in which organisms are actively dividing and the
generation time is constant
Isolated colony on a streak plate contains millions of identical
cells all arising from one initial cell - ANSWER true
Source of nutrients in nutrient agar - ANSWER peptone and
beef extract
