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 a plasmid?

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

What shape are cocci?

  1. ARound
  2. BRod-shaped
  3. CComma-shaped
  4. DSpiral
3.Easy

What is the main function of bacterial flagella?

  1. AStorage of nutrients
  2. BMovement
  3. CAttachment to host cells
  4. DProtection against drying out
4.Medium

What does an ELISA test detect?

  1. ABacterial growth on solid agar plates
  2. BThe DNA sequence of the whole bacterial genome
  3. CThe shape of bacteria under the microscope
  4. DSpecific antigens or antibodies, using an enzyme that causes a colour change
5.Medium

Why does high vaccination coverage also protect babies too young to be vaccinated?

  1. AVaccinated people pass antibodies to everyone they meet
  2. BVaccines kill the pathogen in the environment
  3. CBabies are naturally immune to all vaccine-preventable diseases
  4. DFewer people can pass on the infection, so it spreads less
6.Medium

In the lysogenic cycle of a bacteriophage, what happens to the phage DNA?

  1. AIt leaves the cell through the pilus
  2. BIt is integrated into the bacterial chromosome as a prophage
  3. CIt is destroyed by the bacterium
  4. DIt is immediately used to make new phages that burst the cell
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. AHeat does not kill pneumococci
  2. BRough pneumococci are always more virulent than smooth ones
  3. CA "transforming principle" from dead bacteria could change harmless bacteria into virulent ones
  4. DViruses carry genes between bacteria
8.Hard

Several people vomit within a few hours of eating fried rice that was cooked the day before and kept at room temperature. Which organism is the classic cause?

  1. AClostridium botulinum
  2. BListeria monocytogenes
  3. CBacillus cereus
  4. DSalmonella Typhi

Answer key

  1. 1. A · A small circle of DNA separate from the bacterial chromosome
  2. 2. A · Round
  3. 3. B · Movement
  4. 4. D · Specific antigens or antibodies, using an enzyme that causes a colour change
  5. 5. D · Fewer people can pass on the infection, so it spreads less
  6. 6. B · It is integrated into the bacterial chromosome as a prophage
  7. 7. C · A "transforming principle" from dead bacteria could change harmless bacteria into virulent ones
  8. 8. C · Bacillus cereus

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