Worksheet: Aseptic Techniques

In this worksheet, we will practice explaining the importance of using aseptic techniques when culturing microorganisms.


What aseptic technique can be used to kill airborne pathogens surrounding a working area?

  • AWorking near open windows
  • BWearing gloves
  • CWorking near a bunsen flame
  • DSterilizing surfaces


Schools and universities often instruct students not to eat or drink in science labs.

Why is this instruction given?

  • AFood and drink could become contaminated by microorganisms used in experiments.
  • BIt is a distraction to be eating while working.
  • CIt is difficult to sterilize food and drink containers.
  • DIt takes longer to clear up equipment if there is also food waste.


The average body temperature of a human is 37C. When investigating bacterial growth, why should school laboratories incubate agar plates at 25C?

  • ATo speed up the growth of their bacterial colonies
  • BTo prevent the growth of all microorganisms
  • CTo ensure the growth of a large variety of microorganisms
  • DTo prevent the growth of harmful microorganisms that may infect humans


When scientists culture microorganisms in a lab, they should work aseptically. What is the aim of aseptic techniques?

  • ATo prevent contamination from unwanted microorganisms
  • BTo prevent the growth of any microorganisms
  • CTo provide the best conditions for microbial growth
  • DTo ensure all equipment is working properly


Which of the following is not an example of an aseptic technique?

  • ACleaning surfaces with disinfectant before use
  • BAutoclaving agar plates before and after use
  • CWorking close to an open window
  • DWorking close to a bunsen burner
  • EWearing gloves while working with microorganisms


Why should all doors and windows be closed when working aseptically?

  • ATo prevent the introduction of new microorganisms into the environment
  • BTo prevent humans from coming into contact with airborne microorganisms
  • CTo ensure optimum temperature for microorganism growth
  • DTo kill any airborne microorganisms in the working area


What process describes the unintended introduction of microorganisms that can impact a set of results in cell culture?

  • ACompromisation
  • BInfection
  • CContamination
  • DMicrobial growth
  • EPathogenesis


What part of an experimental setup describes a surface that provides nutrients for microorganisms to grow?

  • AAgar gel
  • BIncubator
  • CPetri dish
  • DWater
  • EAutoclave


The picture provided shows instruments being sterilized at high pressure and temperatures in an autoclave.

Why should equipment be sterilized in an autoclave before being used to culture microorganisms?

Sterilizing medical instruments in autoclave
  • ASo the equipment reaches the best temperatures for microorganism growth
  • BTo ensure that the equipment can kill any microorganisms it comes into contact with
  • CTo remove any preexisting microorganisms on the equipment
  • DThis is untrue; the equipment should only be sterilized after use.


The diagram provided shows an agar plate incubated by a school student. They were attempting to isolate colonies of the red bacteria, but upon collecting their agar plate, they found that colonies of the orange bacteria had grown.

At what temperature should the student have incubated the agar plate?

Which of the following could be a potential reason for the growth of the orange bacteria?

  • APlacing a lid on the agar plate and turning it upside down while incubating
  • BWearing gloves while handling the agar plates
  • CAutoclaving the equipment before use
  • DWorking near open doors and windows
  • EWorking near a bunsen flame

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