Microbiology worksheet with answers

Which of these is a protozoan?

1. ACandida albicans
2. BGiardia lamblia
3. CRotavirus
4. DEscherichia coli

Why are viruses called obligate intracellular parasites?

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

What shape are cocci?

1. ASpiral
2. BRound
3. CComma-shaped
4. DRod-shaped

Which is a function of the complement system?

1. AMaking new red blood cells
2. BForming pores in the membranes of some bacteria
3. CPresenting antigens to T cells
4. DProducing antibodies against newly encountered antigens

Many antifungal drugs target ergosterol. Why does this work?

1. AHuman cells use ergosterol to make energy
2. BErgosterol is the main structural component of bacterial cell walls
3. CErgosterol is in fungal cell membranes but not in human cells
4. DErgosterol is only found in viruses

In the chain of infection, what is the "reservoir"?

1. AThe person who is most at risk of infection
2. BThe route by which the pathogen leaves the infected host's body
3. CThe place where the pathogen normally lives and multiplies
4. DThe way the pathogen enters a new host

A positive blood culture shows Gram-positive cocci in clusters. Which organism is most likely?

1. ANeisseria
2. BStaphylococcus
3. CEnterococcus in short chains
4. DStreptococcus

What is the key difference between bactericidal and bacteriostatic antibiotics?

1. ABacteriostatic drugs always work faster than bactericidal drugs
2. BBactericidal drugs work only outside the body
3. CBactericidal drugs kill bacteria; bacteriostatic drugs stop growth and rely on the immune system to clear them
4. DBactericidal drugs work only on viruses; bacteriostatic drugs work on bacteria