Microbiology worksheet with answers

What is the purpose of pasteurising milk?

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

Why are viruses called obligate intracellular parasites?

1. AThey only live inside the intestine
2. BThey always kill the host cell immediately
3. CThey can only replicate inside a living host cell
4. DThey can only be seen inside a cell under a microscope

What is the most effective single measure to prevent the spread of infection in hospitals?

1. AWearing a face mask at all times
2. BGiving every patient antibiotics
3. CHand hygiene
4. DKeeping windows closed

Which bacterium is the most common cause of stomach ulcers?

1. AClostridioides difficile
2. BHelicobacter pylori
3. CEscherichia coli
4. DStaphylococcus aureus

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

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

What is the incubation period?

1. AThe time a culture needs in the laboratory
2. BThe time between infection and the first symptoms
3. CThe time during which a patient remains infectious to others
4. DThe time an antibiotic takes to work

Gram-positive cocci are found. Which test quickly separates staphylococci from streptococci?

1. AThe acid-fast stain
2. BGrowth on MacConkey agar
3. CThe catalase test
4. DThe coagulase test

Which feature distinguishes most exotoxins from endotoxin?

1. AExotoxins are lipopolysaccharides of the Gram-negative outer membrane
2. BExotoxins are only released when bacteria die
3. CExotoxins are proteins and can be turned into toxoid vaccines
4. DExotoxins are heat-stable lipids