MICR 2123 Final Exam Questions and
Answers
In highlight of what we discussed for microscopy, which of these statements is true? - Answer-
magnification leads to better resolution
This type of microscopy, uses a condenser to collect light rays that are usually scattered and uses them
for visualization. - Answer-dark-field microscopy
In which of these types of light microscopy is the field dark? - Answer-both dark-field and fluroescence
Why do we need to coat specimens with heavy metals when using electron microscopy? - Answer-to
allow the objects to absorb the electron
Out of all microscopy types we studied, this is the only one that shows images in 3D - Answer-SEM
All of these are functions of the cell wall - Answer-conferring rigidity, conferring shape, resistance to
turgor pressure
Pick the component that is present in the cell envelope of ONLY gram-negative bacteria. - Answer-
outer-membrane
,Gram negative and gram positive bacteria differ in the component of their cell membrane - Answer-
peptidoglycan
The ____ component of gram negative bacteria is endotoxic mainly due to its _____ content. - Answer-
LPS; lipid A
Some bacteria motile via - Answer-flagella
Bacteria need these in small amounts in their culture media - Answer-micronutrients
These are major elements required by the cell in large amounts - Answer-macronutrients
Cell membranes are semipermeable structures. Selective permeability occurs through - Answer-
membrane proteins
You have isolated a bacterium from the rumen of a cow and wish to know how it transports the sugar
"whonose" into the cell. You perform an experiment that shows that "whonose" transport uses ATP.
What is the mechanism of "whonose" transport into this cell? - Answer-active transport
These two types of culture media differ in whether their components are defined or not - Answer-
complex and synthetic
_____ are resistant structures that contain the genetic material surrounded by a protective coat -
Answer-endospores
At the optimal growth conditions of an organism, its _____ are most functional and its _____ are intact.
- Answer-proteins; membranes
, Pathogens that causes disease to human need to be successful in surviving at our body temperature.
Accordingly these pathogens are most probably - Answer-mesophiles
T/F: large and/or charged molecules can pass through the cell membrane by diffusion - Answer-false
T/F: movement of molecules across the membrane from regions of low concentration to regions of high
concentrations does not require energy expenditure. - Answer-False
T/F: Pasteurization achieves sterilization - Answer-False
T/F: If nitrogen was limiting in a pond then it was suddenly introduced in large quantities, the pond
water bacterial load will not be affected by the added nitrogen. - Answer-False
T/F: inner layers of a bacterial biofilm are resistant to antibiotics - Answer-True
T/F: On the ocean floor, it is common to find a psychrobarophile. - Answer-True
T/F: In animal guts there is no oxygen. Accordingly, we expect to find strict anaerobes, facultative
anaerobes, as well as strict aerobes. - Answer-False
T/F: If your goal is to see object in the nanometer range, then light microscopy is your best option to
use. - Answer-False
T/F: Using immersion oil with bright field microscopy has no effect on resolution. - Answer-False
In the microbial world, all organisms are about the same size. - Answer-False
Answers
In highlight of what we discussed for microscopy, which of these statements is true? - Answer-
magnification leads to better resolution
This type of microscopy, uses a condenser to collect light rays that are usually scattered and uses them
for visualization. - Answer-dark-field microscopy
In which of these types of light microscopy is the field dark? - Answer-both dark-field and fluroescence
Why do we need to coat specimens with heavy metals when using electron microscopy? - Answer-to
allow the objects to absorb the electron
Out of all microscopy types we studied, this is the only one that shows images in 3D - Answer-SEM
All of these are functions of the cell wall - Answer-conferring rigidity, conferring shape, resistance to
turgor pressure
Pick the component that is present in the cell envelope of ONLY gram-negative bacteria. - Answer-
outer-membrane
,Gram negative and gram positive bacteria differ in the component of their cell membrane - Answer-
peptidoglycan
The ____ component of gram negative bacteria is endotoxic mainly due to its _____ content. - Answer-
LPS; lipid A
Some bacteria motile via - Answer-flagella
Bacteria need these in small amounts in their culture media - Answer-micronutrients
These are major elements required by the cell in large amounts - Answer-macronutrients
Cell membranes are semipermeable structures. Selective permeability occurs through - Answer-
membrane proteins
You have isolated a bacterium from the rumen of a cow and wish to know how it transports the sugar
"whonose" into the cell. You perform an experiment that shows that "whonose" transport uses ATP.
What is the mechanism of "whonose" transport into this cell? - Answer-active transport
These two types of culture media differ in whether their components are defined or not - Answer-
complex and synthetic
_____ are resistant structures that contain the genetic material surrounded by a protective coat -
Answer-endospores
At the optimal growth conditions of an organism, its _____ are most functional and its _____ are intact.
- Answer-proteins; membranes
, Pathogens that causes disease to human need to be successful in surviving at our body temperature.
Accordingly these pathogens are most probably - Answer-mesophiles
T/F: large and/or charged molecules can pass through the cell membrane by diffusion - Answer-false
T/F: movement of molecules across the membrane from regions of low concentration to regions of high
concentrations does not require energy expenditure. - Answer-False
T/F: Pasteurization achieves sterilization - Answer-False
T/F: If nitrogen was limiting in a pond then it was suddenly introduced in large quantities, the pond
water bacterial load will not be affected by the added nitrogen. - Answer-False
T/F: inner layers of a bacterial biofilm are resistant to antibiotics - Answer-True
T/F: On the ocean floor, it is common to find a psychrobarophile. - Answer-True
T/F: In animal guts there is no oxygen. Accordingly, we expect to find strict anaerobes, facultative
anaerobes, as well as strict aerobes. - Answer-False
T/F: If your goal is to see object in the nanometer range, then light microscopy is your best option to
use. - Answer-False
T/F: Using immersion oil with bright field microscopy has no effect on resolution. - Answer-False
In the microbial world, all organisms are about the same size. - Answer-False
