Microbiology worksheet with answers

How is HIV mainly transmitted?

1. AThrough mosquito bites
2. BThrough blood, sexual contact and from mother to child
3. CThrough shared drinking glasses
4. DThrough coughing, sneezing and sharing cups or cutlery with others

What is a bacteriophage?

1. AAn antibiotic made by fungi
2. BA virus that infects bacteria
3. CA bacterium that infects viruses
4. DA white blood cell that eats bacteria

What is an antigen?

1. AA protein made by plasma cells to fight infection
2. BA molecule that the immune system recognises
3. CA drug that blocks bacterial growth
4. DA type of white blood cell

Tetanus and diphtheria vaccines are toxoids. What does that mean?

1. AThey contain ready-made antibodies against the toxin, giving passive immunity
2. BThey contain live bacteria that cannot make toxin
3. CThey contain an inactivated toxin that still triggers an immune response
4. DThey contain the bacterial DNA only

Cholera causes profuse "rice-water" diarrhoea. What is the most important treatment?

1. AStopping all oral fluid intake so that the bowel can rest and recover
2. BAntiviral drugs
3. CReplacing fluid and salts by oral or intravenous rehydration
4. DAntifungal drugs

How is DNA transferred between bacteria during conjugation?

1. ABy fusion of two bacterial cells into one
2. BBy uptake of free DNA from the environment
3. CBy a bacteriophage carrying bacterial DNA
4. DThrough direct contact using a sex pilus

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. AListeria monocytogenes
2. BBacillus cereus
3. CClostridium botulinum
4. DSalmonella Typhi

Why can an HIV antibody test be negative in the first weeks after infection?

1. AHIV does not trigger antibody production at all
2. BThe antibodies are destroyed by the test reagents
3. CThe virus hides only in red blood cells during the first weeks
4. DThe body has not yet produced enough antibodies to detect