BIOL 2321 EXAM 2 QUESTIONS AND
ANSWERS
You have isolated a bacterial species from a fresh water source. The presence of which
structure(s) among A-D could lead you to believe the isolate might be a photosynthetic
or lithotrophic bacterium? - Correct Answers -carboxysome
Which one of the following pairs among A-D is matched correctly? - Correct Answers -
gas vacuoles - suspension in water; depth adjustment
A motile bacterium exhibiting an overabundance of "tumbles" and a low frequency of
"runs" is likely - Correct Answers -not in the presence of chemoattractant
Bacteria carry out bidirectional replication of their single chromosome by using _____
replisomes that each contain _____ DNA polymerase enzymes. - Correct Answers -2; 2
Cytoskeleton element found in rod-shaped bacteria; facilitates cell wall synthesis -
Correct Answers -MreB
Yields a high quantity of polypeptide in a short time interval - Correct Answers -
polysome formation
Protein complex that synthesizes cell envelope material during sepatation - Correct
Answers -divisome
Cytoskeleton element that determines the cell diameter and is required for proper cell
division - Correct Answers -crescentin
Engulfment by the mother cell and deposition of dipicolinic acid highlight this process -
Correct Answers -endospore formation
nutrient addition at mid to late log phase allows for further increase in cell yield - Correct
Answers -fed-batch culture
Cellular communication & exopolysaccharide production characterize this - Correct
Answers -biofilm formation
Responsible for DNA synthesis during chromosome replication - Correct Answers -
replisome
Lacks a nuclear membrane - Correct Answers -ori sequence
, Which term among A-D is not correctly matched with its proper definition? - Correct
Answers -- Carbon: generally has the biggest influence in determining the level of
biomass that can be achieved by a bacterial culture
- Auxotrophs: deficient in a particular metabolic pathway
- Macronutrient: phosphorous and sulfur are in this category
- Growth factor: components, either defined or undefined (like vitamins, blood), that
promote/support growth
Which of the following is false regarding all types of viruses? - Correct Answers -they all
can take in and metabolize food sources for energy
If you were preparing a defined, minimal medium for an aerobic, heterotrophic
bacterium to grow on, which of the following constituents in the medium shown below
would have to be substituted in order for this bacterium to be able to grow?
NOTE: The ingredient listed below, NaHCO3 is used as a source of carbon dioxide as it
forms CO2 in aqueous solution. - Correct Answers -NaHCO3
The growth medium formulation shown is for nutrient agar, a common media used to
cultivate bacteria. Which of the following statements among A-C is likely false
concerning this nutrient agar growth medium? - Correct Answers -From the components
listed, one can assume it can be used to grow autotrophic bacteria.
Engulfment by the mother cell and deposition of dipicolinic acid highlight this process -
Correct Answers -endospore formation
nutrient addition at mid to late log phase allows for further increase in cell yield - Correct
Answers -fed-batch culture
Cellular communication: exopolysaccharide production characterizes this - Correct
Answers -biofilm formation
The host range of a virus is determined by - Correct Answers -whether the glycoproteins
or capsid proteins on its surface recognize those of the host cells.
An organism is classified as a heterotroph or autotroph based on the type of ________
it utilizes.. - Correct Answers -carbon source
Bacterium X has a generation time of 25 minutes. Starting with 20 cells in log phase,
how long does it take to produce about 100,000 cells? - Correct Answers -about 307
minutes
Which statement below regarding membrane structure and membrane transport is true?
- Correct Answers -Cyclization of membrane phospholipid fatty acids (like cyclopropane)
would confer more rigid, straighter hydrocarbon chains.
ANSWERS
You have isolated a bacterial species from a fresh water source. The presence of which
structure(s) among A-D could lead you to believe the isolate might be a photosynthetic
or lithotrophic bacterium? - Correct Answers -carboxysome
Which one of the following pairs among A-D is matched correctly? - Correct Answers -
gas vacuoles - suspension in water; depth adjustment
A motile bacterium exhibiting an overabundance of "tumbles" and a low frequency of
"runs" is likely - Correct Answers -not in the presence of chemoattractant
Bacteria carry out bidirectional replication of their single chromosome by using _____
replisomes that each contain _____ DNA polymerase enzymes. - Correct Answers -2; 2
Cytoskeleton element found in rod-shaped bacteria; facilitates cell wall synthesis -
Correct Answers -MreB
Yields a high quantity of polypeptide in a short time interval - Correct Answers -
polysome formation
Protein complex that synthesizes cell envelope material during sepatation - Correct
Answers -divisome
Cytoskeleton element that determines the cell diameter and is required for proper cell
division - Correct Answers -crescentin
Engulfment by the mother cell and deposition of dipicolinic acid highlight this process -
Correct Answers -endospore formation
nutrient addition at mid to late log phase allows for further increase in cell yield - Correct
Answers -fed-batch culture
Cellular communication & exopolysaccharide production characterize this - Correct
Answers -biofilm formation
Responsible for DNA synthesis during chromosome replication - Correct Answers -
replisome
Lacks a nuclear membrane - Correct Answers -ori sequence
, Which term among A-D is not correctly matched with its proper definition? - Correct
Answers -- Carbon: generally has the biggest influence in determining the level of
biomass that can be achieved by a bacterial culture
- Auxotrophs: deficient in a particular metabolic pathway
- Macronutrient: phosphorous and sulfur are in this category
- Growth factor: components, either defined or undefined (like vitamins, blood), that
promote/support growth
Which of the following is false regarding all types of viruses? - Correct Answers -they all
can take in and metabolize food sources for energy
If you were preparing a defined, minimal medium for an aerobic, heterotrophic
bacterium to grow on, which of the following constituents in the medium shown below
would have to be substituted in order for this bacterium to be able to grow?
NOTE: The ingredient listed below, NaHCO3 is used as a source of carbon dioxide as it
forms CO2 in aqueous solution. - Correct Answers -NaHCO3
The growth medium formulation shown is for nutrient agar, a common media used to
cultivate bacteria. Which of the following statements among A-C is likely false
concerning this nutrient agar growth medium? - Correct Answers -From the components
listed, one can assume it can be used to grow autotrophic bacteria.
Engulfment by the mother cell and deposition of dipicolinic acid highlight this process -
Correct Answers -endospore formation
nutrient addition at mid to late log phase allows for further increase in cell yield - Correct
Answers -fed-batch culture
Cellular communication: exopolysaccharide production characterizes this - Correct
Answers -biofilm formation
The host range of a virus is determined by - Correct Answers -whether the glycoproteins
or capsid proteins on its surface recognize those of the host cells.
An organism is classified as a heterotroph or autotroph based on the type of ________
it utilizes.. - Correct Answers -carbon source
Bacterium X has a generation time of 25 minutes. Starting with 20 cells in log phase,
how long does it take to produce about 100,000 cells? - Correct Answers -about 307
minutes
Which statement below regarding membrane structure and membrane transport is true?
- Correct Answers -Cyclization of membrane phospholipid fatty acids (like cyclopropane)
would confer more rigid, straighter hydrocarbon chains.
