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 main purpose of bacterial endospores?

  1. ATo reproduce quickly when nutrients and water are plentiful
  2. BTo survive harsh conditions such as heat and drying
  3. CTo move towards nutrients
  4. DTo exchange DNA with other bacteria
2.Easy

In infection control, what is a vector?

  1. AA drug used to prevent infection
  2. BThe first person infected in an outbreak
  3. CA living organism that carries a pathogen from one host to another
  4. DAn object such as a door handle that carries germs between patients on a ward
3.Easy

What is sterilisation?

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

Which is a function of the complement system?

  1. AProducing antibodies against newly encountered antigens
  2. BPresenting antigens to T cells
  3. CForming pores in the membranes of some bacteria
  4. DMaking new red blood cells
5.Medium

Why are pregnant women advised to avoid unpasteurised soft cheeses?

  1. AThey contain too much lactose for the fetus
  2. BThey may contain tapeworm eggs
  3. CThey often contain the hepatitis C virus, which crosses the placenta
  4. DThey may contain Listeria, which can harm the fetus
6.Medium

MRSA is resistant to methicillin because it has:

  1. AAn efflux pump for every antibiotic
  2. BAn altered penicillin-binding protein (PBP2a)
  3. CA polysaccharide capsule that blocks the entry of all beta-lactams
  4. DNo cell wall at all
7.Hard

In Griffith's 1928 experiment, mice died after injection of heat-killed smooth (S) pneumococci mixed with live rough (R) pneumococci. What did this show?

  1. AA "transforming principle" from dead bacteria could change harmless bacteria into virulent ones
  2. BHeat does not kill pneumococci
  3. CRough pneumococci are always more virulent than smooth ones
  4. DViruses carry genes between bacteria
8.Hard

Staphylococcus aureus food poisoning starts only 1–6 hours after eating. Why so fast?

  1. AThe bacteria invade the bloodstream immediately
  2. BThe immune system reacts to the bacteria within minutes
  3. CThe bacteria multiply very fast inside the gut and invade the intestinal wall
  4. DThe bacteria made a heat-stable toxin in the food before it was eaten

Answer key

  1. 1. B · To survive harsh conditions such as heat and drying
  2. 2. C · A living organism that carries a pathogen from one host to another
  3. 3. D · Killing or removing all microorganisms including spores
  4. 4. C · Forming pores in the membranes of some bacteria
  5. 5. D · They may contain Listeria, which can harm the fetus
  6. 6. B · An altered penicillin-binding protein (PBP2a)
  7. 7. A · A "transforming principle" from dead bacteria could change harmless bacteria into virulent ones
  8. 8. D · The bacteria made a heat-stable toxin in the food before it was eaten

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