MICROBIOLOGY LECTURE EXAM #2
QUESTIONS AND ANSWERS
Most bacteria reproduce by
a) aerial hyphae
b) fragmentation
c) mitosis
d) binary fission
e) budding - Correct Answers -d
An isolated colony on a streak plate could contain millions of identical cells.
true
false - Correct Answers -true
Bacteria require nutrients from their environment to survive. Which of these elements is
not correctly matched with its function?
a) carbon: energy source and structural molecules
b) nitrogen: in amino acids
c) phosphorus: DNA, RNA, ATP
d) oxygen: necessary for carbohydrate metabolism - Correct Answers -d
Pathogenic bacteria isolated from the respiratory tract of humans are most likely
a) strict aerobes that grow best in candle jars
b) capnophiles that grow best in carbon dioxide incubators
c) facultative anaerobes that require reducing media for growth
d) strict aerobes that grow best reducing media
e) capnophiles that prefer highly oxygenated growth conditions - Correct Answers -b
Salts and sugars work to preserve foods by creating a
a) depletion of nutrients
b) hypotonic environment
c) lower osmotic pressure
d) hypertonic environment
e) lower pH - Correct Answers -d
, The term aerotolerant anaerobe refers to an organism that
a) does not 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) requires more oxygen than is present in air - Correct Answers -a
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 - Correct Answers -b
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 - Correct Answers –d
Which of the following does not achieve sterilization?
a) dry heat
b) pasteurization
c) autoclave
d) supercritical fluids
e) ethylene oxide - Correct Answers -b
Which concentration of ethanol is the most effective bactericide?
a) 100%
b) 70%
c) 50%
d) 40%
e) 30% - Correct Answers -b
Which of the following is/are used to mechanically remove microbes through
mechanical action and physical removal?
a) alcohol
b) biguanides
QUESTIONS AND ANSWERS
Most bacteria reproduce by
a) aerial hyphae
b) fragmentation
c) mitosis
d) binary fission
e) budding - Correct Answers -d
An isolated colony on a streak plate could contain millions of identical cells.
true
false - Correct Answers -true
Bacteria require nutrients from their environment to survive. Which of these elements is
not correctly matched with its function?
a) carbon: energy source and structural molecules
b) nitrogen: in amino acids
c) phosphorus: DNA, RNA, ATP
d) oxygen: necessary for carbohydrate metabolism - Correct Answers -d
Pathogenic bacteria isolated from the respiratory tract of humans are most likely
a) strict aerobes that grow best in candle jars
b) capnophiles that grow best in carbon dioxide incubators
c) facultative anaerobes that require reducing media for growth
d) strict aerobes that grow best reducing media
e) capnophiles that prefer highly oxygenated growth conditions - Correct Answers -b
Salts and sugars work to preserve foods by creating a
a) depletion of nutrients
b) hypotonic environment
c) lower osmotic pressure
d) hypertonic environment
e) lower pH - Correct Answers -d
, The term aerotolerant anaerobe refers to an organism that
a) does not 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) requires more oxygen than is present in air - Correct Answers -a
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 - Correct Answers -b
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 - Correct Answers –d
Which of the following does not achieve sterilization?
a) dry heat
b) pasteurization
c) autoclave
d) supercritical fluids
e) ethylene oxide - Correct Answers -b
Which concentration of ethanol is the most effective bactericide?
a) 100%
b) 70%
c) 50%
d) 40%
e) 30% - Correct Answers -b
Which of the following is/are used to mechanically remove microbes through
mechanical action and physical removal?
a) alcohol
b) biguanides
