Microbiology worksheet with answers

What colour do Gram-positive bacteria stain in a Gram stain?

1. AColourless
2. BGreen
3. CPurple
4. DPink

Which is part of the body's first line of defence against infection?

1. ACytotoxic T cells
2. BMemory B cells
3. CIntact skin
4. DAntibodies

What is sterilisation?

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

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

1. AIt is immediately used to make new phages that burst the cell
2. BIt leaves the cell through the pilus
3. CIt is destroyed by the bacterium
4. DIt is integrated into the bacterial chromosome as a prophage

Transfer of bacterial genes from one bacterium to another by a virus is called:

1. ATranscription
2. BTransduction
3. CConjugation
4. DTransformation

Which type of immunity is given by breast milk antibodies?

1. ANatural passive immunity
2. BNatural active immunity
3. CArtificial active immunity
4. DArtificial passive immunity

Which bacterial toxin causes the muscle spasms of tetanus?

1. ACholera toxin, which activates adenylate cyclase
2. BTetanospasmin, which blocks inhibitory neurotransmitter release
3. CEndotoxin from the outer membrane
4. DBotulinum toxin, which blocks acetylcholine release at the neuromuscular junction

The minimum inhibitory concentration (MIC) of an antibiotic is:

1. AThe lowest concentration that prevents visible bacterial growth in vitro
2. BThe plasma level at which side effects begin
3. CThe lowest concentration that kills 99.9% of the bacterial inoculum in vitro
4. DThe highest dose a patient can tolerate