Microbiology worksheet with answers

Free printable Microbiology worksheet: 8 problems from easy to exam level, with an answer key. Print it or save it as a PDF.

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1.Easy

What is the purpose of pasteurising milk?

  1. ATo add healthy bacteria to the milk
  2. BTo kill all microorganisms, including bacterial spores, by heating
  3. CTo kill pathogens by heating, without fully sterilising it
  4. DTo remove fat from the milk
2.Easy

What is sterilisation?

  1. AKilling or removing all microorganisms including spores
  2. BCleaning visible dirt from surfaces
  3. CReducing the number of microorganisms to a level safe for patients
  4. DKilling only bacteria but not viruses
3.Easy

What is a plasmid?

  1. AThe protein coat of a virus
  2. BA small circle of DNA separate from the bacterial chromosome
  3. CA layer of sugar around the bacterial cell that protects it from phagocytosis
  4. DA type of bacterial ribosome
4.Medium

Which vaccine contains live attenuated (weakened) viruses?

  1. AHepatitis B vaccine
  2. BTetanus vaccine
  3. CInactivated influenza injection
  4. DMMR (measles, mumps, rubella)
5.Medium

In which phase of the bacterial growth curve do the cells divide at their fastest constant rate?

  1. ALag (adaptation) phase
  2. BDeath phase
  3. CLog (exponential) phase
  4. DStationary (plateau) phase
6.Medium

How do people usually become infected with Legionella pneumophila?

  1. ABy being bitten by an infected tick
  2. BBy person-to-person spread through kissing
  3. CBy eating undercooked chicken or unpasteurised milk products
  4. DBy inhaling aerosols from contaminated water systems
7.Hard

Joseph Lister reduced infection after surgery in the 1860s. What was his main innovation?

  1. AUsing carbolic acid (phenol) as an antiseptic on wounds and instruments
  2. BUsing steam autoclaves to sterilise all surgical instruments before each operation
  3. CGiving sulfonamide antibiotics after every operation
  4. DVaccinating surgeons against staphylococci
8.Hard

A healthcare worker's blood test is positive for anti-HBs (hepatitis B surface antibody) and negative for HBsAg and anti-HBc. What does this most likely mean?

  1. AImmunity from hepatitis B vaccination
  2. BPast natural infection that has cleared
  3. CChronic hepatitis B infection
  4. DCurrent acute hepatitis B infection

Answer key

  1. 1. C · To kill pathogens by heating, without fully sterilising it
  2. 2. A · Killing or removing all microorganisms including spores
  3. 3. B · A small circle of DNA separate from the bacterial chromosome
  4. 4. D · MMR (measles, mumps, rubella)
  5. 5. C · Log (exponential) phase
  6. 6. D · By inhaling aerosols from contaminated water systems
  7. 7. A · Using carbolic acid (phenol) as an antiseptic on wounds and instruments
  8. 8. A · Immunity from hepatitis B vaccination

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