MICR 271 - Module 3 Questions With Complete Solutions
How are plaque assays performed? Correct Answers 1.
Bacterial colonies are washed with different viral
concentrations.
2. Agarose is added in order to increase viscosity (without it,
viruses could spread from bacterium to bacterium. This way, the
viruses only infect the cells they come into contact with.)
3. A dye (trypan blue) is added. The uninfected cells are dyed
blue and the infected cells are died white (plaques)
4. Number of plaque forming units (PFU) can be counted.
How do bacterial populations divide? Correct Answers Binary
fission.
1. Chromosome replication
2. Continued growth
3. Division into two daughter cells.
How do Reactive Oxygen Species come to be, and what are
they? Correct Answers Proteins transfer electrons from oxygen,
making it unstable. ROS can damage DNA and important
molecules within the body. These include peroxide, hydroxyl
radicals, and more.
How is a hemocytometer used? Correct Answers Proper
dilution of bacteria is accomplished.
1. Clean hemacytometer + wet the edges. Rest the cover slip
over top.
2. Fill two chambers with the cell suspensions. Let the solution
set + take off any excess liquid
3. Count the cells.
, How is quorum sensing accomplished in a gram positive cell?
Correct Answers Autoinducer binds to a receptor outside of the
cell which then activates a cascade and alters gene expression.
How is quorum sensing accomplished in gram negative
bacteria? Correct Answers Autoinducer is taken into the cell,
binds to an intracellular receptor and acts as a transcriptional
regulator.
What are all required nutrients for living organisms? Correct
Answers Central: Carbon (photosynthesis, prokaryotic
breakdown) and nitrogen (nitrifying bacteria turn NH3 to NO2
or NO3).
Minor: Vitamins, Hydrogen, Trace elements (other chemical
compounds found in small concentrations within the organism).
What are autoinducers? Correct Answers Signalling molecules
produced and secreted by quorum sensing bacteria. They change
a bacterium's gene expression when at threshold concentrations.
What are different ways of producing ATP? Correct Answers
1. Respiration
2. Fermentation
What are natural killer cells? Correct Answers Non
phagocytotic cells which secrete proteins (activate apoptosis).
They target in one of two ways.
1. Recognizing antibodies.
2. Activation of target cell receptors for cell death.
How are plaque assays performed? Correct Answers 1.
Bacterial colonies are washed with different viral
concentrations.
2. Agarose is added in order to increase viscosity (without it,
viruses could spread from bacterium to bacterium. This way, the
viruses only infect the cells they come into contact with.)
3. A dye (trypan blue) is added. The uninfected cells are dyed
blue and the infected cells are died white (plaques)
4. Number of plaque forming units (PFU) can be counted.
How do bacterial populations divide? Correct Answers Binary
fission.
1. Chromosome replication
2. Continued growth
3. Division into two daughter cells.
How do Reactive Oxygen Species come to be, and what are
they? Correct Answers Proteins transfer electrons from oxygen,
making it unstable. ROS can damage DNA and important
molecules within the body. These include peroxide, hydroxyl
radicals, and more.
How is a hemocytometer used? Correct Answers Proper
dilution of bacteria is accomplished.
1. Clean hemacytometer + wet the edges. Rest the cover slip
over top.
2. Fill two chambers with the cell suspensions. Let the solution
set + take off any excess liquid
3. Count the cells.
, How is quorum sensing accomplished in a gram positive cell?
Correct Answers Autoinducer binds to a receptor outside of the
cell which then activates a cascade and alters gene expression.
How is quorum sensing accomplished in gram negative
bacteria? Correct Answers Autoinducer is taken into the cell,
binds to an intracellular receptor and acts as a transcriptional
regulator.
What are all required nutrients for living organisms? Correct
Answers Central: Carbon (photosynthesis, prokaryotic
breakdown) and nitrogen (nitrifying bacteria turn NH3 to NO2
or NO3).
Minor: Vitamins, Hydrogen, Trace elements (other chemical
compounds found in small concentrations within the organism).
What are autoinducers? Correct Answers Signalling molecules
produced and secreted by quorum sensing bacteria. They change
a bacterium's gene expression when at threshold concentrations.
What are different ways of producing ATP? Correct Answers
1. Respiration
2. Fermentation
What are natural killer cells? Correct Answers Non
phagocytotic cells which secrete proteins (activate apoptosis).
They target in one of two ways.
1. Recognizing antibodies.
2. Activation of target cell receptors for cell death.
