MICR 290 Final Exam || Errorless Answers 100%.
Biohazards correct answers Biological materials that can represent a health hazard to humans,
animals, or plants.
Include a wide range of potentially infectious agents, such as bacteria, viruses, fungi, parasites,
& prions.
Risk group 1 correct answers Individual risk: low
Community risk: low
Risk group 2 correct answers Individual risk: moderate
Community risk: low
Risk group 3 correct answers Individual risk: high
Community risk: low
Risk group 4 correct answers Individual risk: high
Community risk: high
Conditions that research labs are required to operate under correct answers Containment levels
(CLs) or Biosafety levels (BSLs) → numbered according to the biohazard risk group that can be
studied in that lab
CL of Queen's laboratories correct answers CL1 & CL2
How many CL4 labs in Canada, and where? correct answers 1, at the National Microbiology
Laboratories in Winnipeg
,Safe handling & disposal of biohazards correct answers Personal Protective Equipment (PPE)
Lab coats are absolutely required, (even with Risk Group 1 biohazards). Lab goggles are also
recommended, particularly while carrying out experiments that can generate aerosols.
Sterilization & Disposal
Lab materials that have been in contact with bacteria (ex: tubes, pipette tips, etc) should be
sterilized, using bleach or an autoclave. Once biohazardous waste is decontaminated, it can be
disposed of with regular non-contaminated lab waste. The surface of the lab bench must be
sterilized using 10% bleach or 70% ethanol. Lab-based research also requires WHMIS training.
Aseptic technique correct answers Strategies and approaches designed to create a sterile
environment, limiting potential contamination by microorganisms
Pipettes correct answers Used to transfer volumes ranging from 1mL - 0.1μL
Advantages of pipettes correct answers - Contaminated pipette tips can be easily disposed of in
waste that is to be autoclaved (a measuring cylinder would have to be sterilized)
- More accurate than cylinders for transferring small volumes
- Cheaper and easier to decontaminate than syringes
How to use pipettes correct answers Step 1: Preparation
To transfer a solution, the plunger at the top of the pipette is first depressed, which lowers the
piston. In this step, the plunger is depressed to the first stop.
Step 2: Aspiration
The affixed pipette tip is placed in the solution, and the plunger is released, raising the piston.
This creates a vacuum, drawing the solution into the pipette tip.
Step 3: Dispense & Purge
,Then, the solution is transferred into a different container by depressing the plunger, which
lowers the piston, and ejects the solution. The plunger is depressed to the second stop, ensuring
that all of the solution is expelled from the pipette tip.
Step 4: Home
The pipette tip is removed from the solution, and the plunger is released, returning it to the rest
position.
Aspects of aseptic technique correct answers Lab surfaces are wiped down with 10% bleach or
70% ethanol before AND after experiments.
Pipette tips, lab solutions, and media for growing bacteria are autoclaved. Autoclaves use high
pressure steam to kill bacteria. Other lab tools are wiped down with bleach or ethanol.
Sterile containers (ex: boxes containing pipette tips, Petri dishes) are kept closed to external air
as much as possible.
A Bunsen burner can be used to sterilize common microbiological tools (inoculation loops,
forceps) and the openings of sterile bottles and containers. They also generate airflow on the
bench surface, to draw airborne contaminants away from research samples and equipment.
For research involving biohazards in Risk Groups 2+, experiments are carried out in biosafety
cabinets. The air inside biosafety cabinets is passed through a High-Efficiency Particulate Air
(HEPA) filter, removing microorganisms. The exhaust air is usually also filtered, preventing the
spread of biohazards into the environment.
Bacterial cell division correct answers Binary fission: a process in which one bacterial cell
divides into two identical cells
How are bacteria grown? correct answers In liquid media or solid media
, Liquid media correct answers Composed of ingredients that are required to support the growth of
bacteria, including sources of carbon (sugars), nitrogen (amino acids), and salts (NaCl). Liquid
media is prepared by weighing out the individual ingredients, dissolving them in water, and then
sterilizing the solution through autoclaving.
There are many kinds of liquid media, suitable for varying kinds of bacteria. One of the most
common is lysogen broth (LB), which consists of tryptone (a mixture of peptides formed by
treating milk protein with an enzyme), yeast extract, and sodium chloride.
Solid media correct answers Prepared by adding agar, a thickening agent, to the ingredients used
for liquid media. Agar becomes soluble when heated, and forms a thick gel-like substance when
cooled. Solid media is prepared by autoclaving liquid media to which agar has been added. This
dissolves the agar, making a molten agar solution. The molten agar can then be cured into Petri
dishes, where it solidifies as it cools.
Pure culture correct answers Culturing a single type of bacteria, without other kinds of bacteria
present
How to obtain a pure culture correct answers Agar plates → When a sample containing bacteria
is applied to an agar plate, the individual bacterial cells spread out over the surface of the agar. If
the agar plate is then incubated under conditions that promote bacterial growth, the cells on the
plate replicate, and each forming a bacterial colony.
Cells from a colony can be transferred into new growth media using an inoculation loop, to grow
a pure culture.
Colony correct answers Macroscopic three-dimensional clusters of bacteria cells, in which all of
the cells are derived from a single bacterial cell; colonies are clonal
Clonal correct answers All of the bacterial cells (in a colony) are identical
Biohazards correct answers Biological materials that can represent a health hazard to humans,
animals, or plants.
Include a wide range of potentially infectious agents, such as bacteria, viruses, fungi, parasites,
& prions.
Risk group 1 correct answers Individual risk: low
Community risk: low
Risk group 2 correct answers Individual risk: moderate
Community risk: low
Risk group 3 correct answers Individual risk: high
Community risk: low
Risk group 4 correct answers Individual risk: high
Community risk: high
Conditions that research labs are required to operate under correct answers Containment levels
(CLs) or Biosafety levels (BSLs) → numbered according to the biohazard risk group that can be
studied in that lab
CL of Queen's laboratories correct answers CL1 & CL2
How many CL4 labs in Canada, and where? correct answers 1, at the National Microbiology
Laboratories in Winnipeg
,Safe handling & disposal of biohazards correct answers Personal Protective Equipment (PPE)
Lab coats are absolutely required, (even with Risk Group 1 biohazards). Lab goggles are also
recommended, particularly while carrying out experiments that can generate aerosols.
Sterilization & Disposal
Lab materials that have been in contact with bacteria (ex: tubes, pipette tips, etc) should be
sterilized, using bleach or an autoclave. Once biohazardous waste is decontaminated, it can be
disposed of with regular non-contaminated lab waste. The surface of the lab bench must be
sterilized using 10% bleach or 70% ethanol. Lab-based research also requires WHMIS training.
Aseptic technique correct answers Strategies and approaches designed to create a sterile
environment, limiting potential contamination by microorganisms
Pipettes correct answers Used to transfer volumes ranging from 1mL - 0.1μL
Advantages of pipettes correct answers - Contaminated pipette tips can be easily disposed of in
waste that is to be autoclaved (a measuring cylinder would have to be sterilized)
- More accurate than cylinders for transferring small volumes
- Cheaper and easier to decontaminate than syringes
How to use pipettes correct answers Step 1: Preparation
To transfer a solution, the plunger at the top of the pipette is first depressed, which lowers the
piston. In this step, the plunger is depressed to the first stop.
Step 2: Aspiration
The affixed pipette tip is placed in the solution, and the plunger is released, raising the piston.
This creates a vacuum, drawing the solution into the pipette tip.
Step 3: Dispense & Purge
,Then, the solution is transferred into a different container by depressing the plunger, which
lowers the piston, and ejects the solution. The plunger is depressed to the second stop, ensuring
that all of the solution is expelled from the pipette tip.
Step 4: Home
The pipette tip is removed from the solution, and the plunger is released, returning it to the rest
position.
Aspects of aseptic technique correct answers Lab surfaces are wiped down with 10% bleach or
70% ethanol before AND after experiments.
Pipette tips, lab solutions, and media for growing bacteria are autoclaved. Autoclaves use high
pressure steam to kill bacteria. Other lab tools are wiped down with bleach or ethanol.
Sterile containers (ex: boxes containing pipette tips, Petri dishes) are kept closed to external air
as much as possible.
A Bunsen burner can be used to sterilize common microbiological tools (inoculation loops,
forceps) and the openings of sterile bottles and containers. They also generate airflow on the
bench surface, to draw airborne contaminants away from research samples and equipment.
For research involving biohazards in Risk Groups 2+, experiments are carried out in biosafety
cabinets. The air inside biosafety cabinets is passed through a High-Efficiency Particulate Air
(HEPA) filter, removing microorganisms. The exhaust air is usually also filtered, preventing the
spread of biohazards into the environment.
Bacterial cell division correct answers Binary fission: a process in which one bacterial cell
divides into two identical cells
How are bacteria grown? correct answers In liquid media or solid media
, Liquid media correct answers Composed of ingredients that are required to support the growth of
bacteria, including sources of carbon (sugars), nitrogen (amino acids), and salts (NaCl). Liquid
media is prepared by weighing out the individual ingredients, dissolving them in water, and then
sterilizing the solution through autoclaving.
There are many kinds of liquid media, suitable for varying kinds of bacteria. One of the most
common is lysogen broth (LB), which consists of tryptone (a mixture of peptides formed by
treating milk protein with an enzyme), yeast extract, and sodium chloride.
Solid media correct answers Prepared by adding agar, a thickening agent, to the ingredients used
for liquid media. Agar becomes soluble when heated, and forms a thick gel-like substance when
cooled. Solid media is prepared by autoclaving liquid media to which agar has been added. This
dissolves the agar, making a molten agar solution. The molten agar can then be cured into Petri
dishes, where it solidifies as it cools.
Pure culture correct answers Culturing a single type of bacteria, without other kinds of bacteria
present
How to obtain a pure culture correct answers Agar plates → When a sample containing bacteria
is applied to an agar plate, the individual bacterial cells spread out over the surface of the agar. If
the agar plate is then incubated under conditions that promote bacterial growth, the cells on the
plate replicate, and each forming a bacterial colony.
Cells from a colony can be transferred into new growth media using an inoculation loop, to grow
a pure culture.
Colony correct answers Macroscopic three-dimensional clusters of bacteria cells, in which all of
the cells are derived from a single bacterial cell; colonies are clonal
Clonal correct answers All of the bacterial cells (in a colony) are identical
