MIP 300 Final Exam with Questions and Verified
Answers |Graded A+
In an endospore stain, the positive cells will have which of the following appearances? -
✔✔Green spots within a red cell
Species can be broken down even further. What are different groupings within species
called in viruses? - ✔✔Strains
What components of the peptidoglycan can be altered to change the thickness of a
Gram-Negative peptidoglycan layer? - ✔✔The number of NAG and NAM sheets
(Gram0Negative bacteria don't have interbridges, only direct covalent linkage between
tetrapeptides, thus the number of NAG-NAM sheets is the only factor contributing to
varied thickness of the Gram-Ngative ppg)
What components of the peptidoglycan can be altered to change the thickness of a
Gram-Positive peptidoglycan layer? - ✔✔A) the number of NAG and NAM sheets
B) the type of amino acids in the interbridge
C) the number of amino acids in the interbridge
D) A and B
E) A, B and C (CORRCT)
Gram-Positive can have different numbers of NAG-NAM sheets, and there can be
different types and different numbers of amino acids within the interbridges, all of
which alter the thickness of the ppg)
You do a Gram stain. You realize when you finish that you forgot to add Gram's Iodine.
What color will a Gram-Positive cell be at the end of staining? - ✔✔Pink
,Crystal violet is NOT retained within the thick ppg(since it isn't aggregated with the
mordant) upon the wash step, thus it will stain pink from the secondary stain
You isolate a cell and find that it has 70S ribosomes. This cell could be -
✔✔Prokaryote
Eukaryotes
Either Prokaryote or Eukaryote (CORREECT)
Because both cell types have 70S ribosomes. The prokaryote have only 70S ribosomes.
Eukaryotes, on the other hand, have 80S ribosomes that callry out the majority of
protein synthesis for the cell, but they also have 70S ribosomes in their mitochondria
and chloroplasts(endosymbiont theory)
(True/False)
Plasmids are not required for bacterial cell growth or reproduction - ✔✔True
plasmids are not requires by the cell, but they do confer upon the cell selective
advantage
(True/False)
Most spore-forming bacteria are Gram-Positive - ✔✔True
(True/False)
Sporulation allows a bacterial cell to survive harsh conditions by causing it to divide into
two cells - ✔✔False
,correct, sporulation is not a reproduction process. It merely allows the bacterium to
survive adverse conditions
When performing a chemorepellent assay, why does the zone where bacteria have
moved away from the disc get larger as the concentration of toxin gets higher? -
✔✔The higher the concentration of the toxin the further it will diffuse from the disc,
so the further the bacterium must move to avoid it
exactly! the laws of diffusion means that as the concentration of the antibiotic
increases, the more it will move outward, thus the more the bacteria will need to move
away to avoid the antibiotic
(True/False)
When microbiologist talk about bacterial growth, they are typically referring to an
increase in bacterial cell numbers and not cell size - ✔✔True
You have isolated a newly discovered mesophilic bacterium. You find that at 38 degrees
Celsius, the bacteria grow to 1x10^6 cells. If you move this organism to 10 degrees
Celsius, you would expect the generation time of this organism to - ✔✔increase
Correct, since this organism is a mesophile, it will not grow as well at the cooler
temperature, so the time it takes it to double will increase
Each bacterial colony on this agar plate started out as approximately - ✔✔1 bacterial
cell
You isolate a bacterium and chemically analyze its peptidoglycan. You find that it
contains 8 different types of amino acids and 2 types of carbohydrate. What type of
bacterium could this have been isolated from? - ✔✔Gram Positive
, You isolate a bacterium and chemically analyze its peptidoglycan. You find that it
contains 7 different types of amino acids and 2 types of carbohydrate. What type of
bacterium could this have been isolated from? - ✔✔Gram Positive
You isolate a bacterium and chemically analyze its peptidoglycan. You find that it
contains 5 different types of amino acids and 2 types of carbohydrate. What type of
bacterium could this have been isolated from? - ✔✔Gram Positive
Which of the following can be altered in a Gram negative organism, giving rise to
differing thickness in the peptidoglycan layer? - ✔✔Number of sheets
(True/False)
The number of amino acids in the tetrapeptide can not be altered in either Gram
positive or Gram negative bacteria - ✔✔True
(True/False)
Gram positive organisms will often contain more types of carbohydrates in their
peptidoglycan than Gram negative organisms - ✔✔False
Which of the following will have 70S ribosomes? - ✔✔1) Bacteria
2) Fungi
3) Viruses
4) 1 and 2 (CORRECT)
(True/False)
Answers |Graded A+
In an endospore stain, the positive cells will have which of the following appearances? -
✔✔Green spots within a red cell
Species can be broken down even further. What are different groupings within species
called in viruses? - ✔✔Strains
What components of the peptidoglycan can be altered to change the thickness of a
Gram-Negative peptidoglycan layer? - ✔✔The number of NAG and NAM sheets
(Gram0Negative bacteria don't have interbridges, only direct covalent linkage between
tetrapeptides, thus the number of NAG-NAM sheets is the only factor contributing to
varied thickness of the Gram-Ngative ppg)
What components of the peptidoglycan can be altered to change the thickness of a
Gram-Positive peptidoglycan layer? - ✔✔A) the number of NAG and NAM sheets
B) the type of amino acids in the interbridge
C) the number of amino acids in the interbridge
D) A and B
E) A, B and C (CORRCT)
Gram-Positive can have different numbers of NAG-NAM sheets, and there can be
different types and different numbers of amino acids within the interbridges, all of
which alter the thickness of the ppg)
You do a Gram stain. You realize when you finish that you forgot to add Gram's Iodine.
What color will a Gram-Positive cell be at the end of staining? - ✔✔Pink
,Crystal violet is NOT retained within the thick ppg(since it isn't aggregated with the
mordant) upon the wash step, thus it will stain pink from the secondary stain
You isolate a cell and find that it has 70S ribosomes. This cell could be -
✔✔Prokaryote
Eukaryotes
Either Prokaryote or Eukaryote (CORREECT)
Because both cell types have 70S ribosomes. The prokaryote have only 70S ribosomes.
Eukaryotes, on the other hand, have 80S ribosomes that callry out the majority of
protein synthesis for the cell, but they also have 70S ribosomes in their mitochondria
and chloroplasts(endosymbiont theory)
(True/False)
Plasmids are not required for bacterial cell growth or reproduction - ✔✔True
plasmids are not requires by the cell, but they do confer upon the cell selective
advantage
(True/False)
Most spore-forming bacteria are Gram-Positive - ✔✔True
(True/False)
Sporulation allows a bacterial cell to survive harsh conditions by causing it to divide into
two cells - ✔✔False
,correct, sporulation is not a reproduction process. It merely allows the bacterium to
survive adverse conditions
When performing a chemorepellent assay, why does the zone where bacteria have
moved away from the disc get larger as the concentration of toxin gets higher? -
✔✔The higher the concentration of the toxin the further it will diffuse from the disc,
so the further the bacterium must move to avoid it
exactly! the laws of diffusion means that as the concentration of the antibiotic
increases, the more it will move outward, thus the more the bacteria will need to move
away to avoid the antibiotic
(True/False)
When microbiologist talk about bacterial growth, they are typically referring to an
increase in bacterial cell numbers and not cell size - ✔✔True
You have isolated a newly discovered mesophilic bacterium. You find that at 38 degrees
Celsius, the bacteria grow to 1x10^6 cells. If you move this organism to 10 degrees
Celsius, you would expect the generation time of this organism to - ✔✔increase
Correct, since this organism is a mesophile, it will not grow as well at the cooler
temperature, so the time it takes it to double will increase
Each bacterial colony on this agar plate started out as approximately - ✔✔1 bacterial
cell
You isolate a bacterium and chemically analyze its peptidoglycan. You find that it
contains 8 different types of amino acids and 2 types of carbohydrate. What type of
bacterium could this have been isolated from? - ✔✔Gram Positive
, You isolate a bacterium and chemically analyze its peptidoglycan. You find that it
contains 7 different types of amino acids and 2 types of carbohydrate. What type of
bacterium could this have been isolated from? - ✔✔Gram Positive
You isolate a bacterium and chemically analyze its peptidoglycan. You find that it
contains 5 different types of amino acids and 2 types of carbohydrate. What type of
bacterium could this have been isolated from? - ✔✔Gram Positive
Which of the following can be altered in a Gram negative organism, giving rise to
differing thickness in the peptidoglycan layer? - ✔✔Number of sheets
(True/False)
The number of amino acids in the tetrapeptide can not be altered in either Gram
positive or Gram negative bacteria - ✔✔True
(True/False)
Gram positive organisms will often contain more types of carbohydrates in their
peptidoglycan than Gram negative organisms - ✔✔False
Which of the following will have 70S ribosomes? - ✔✔1) Bacteria
2) Fungi
3) Viruses
4) 1 and 2 (CORRECT)
(True/False)
