Microbiology worksheet with answers

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

1. AMemory B cells
2. BAntibodies
3. CCytotoxic T cells
4. DIntact skin

What does "endemic" mean in epidemiology?

1. AOccurring as a sudden outbreak well above the expected level in an area
2. BSpreading quickly across the whole world
3. CFound only in animals
4. DConstantly present in a population or region at a usual level

What is a pandemic?

1. AA single case of a rare disease
2. BAn epidemic that spreads across several countries or continents
3. CA disease that is always present at a low, stable level in a region
4. DAn outbreak limited to one hospital ward

Which vaccine contains live attenuated (weakened) viruses?

1. AInactivated influenza injection
2. BTetanus vaccine
3. CHepatitis B vaccine
4. DMMR (measles, mumps, rubella)

What does PCR do in a diagnostic laboratory?

1. AIt grows bacteria faster on agar plates
2. BIt makes many copies of a specific DNA sequence so it can be detected
3. CIt measures the level of specific antibodies in a patient's serum sample
4. DIt stains bacteria so they can be seen

Which cells does HIV mainly infect and destroy?

1. ACD4 T helper cells
2. BPlatelets
3. CRed blood cells
4. DNeutrophils

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

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

Why must a negative-sense RNA virus such as influenza carry its own RNA-dependent RNA polymerase into the host cell?

1. AThe polymerase is needed to integrate the genome into host DNA
2. BHost cells cannot make mRNA from an RNA template
3. CHost ribosomes cannot read any viral genes
4. DThe polymerase protects the virus from antibodies