11 Based on shared versus unique properties which two catego

11. Based on shared versus unique properties, which two categories of pathogen do you think might be treated most differently by the immune response?

a. viruses and intracellular bacteria

b. viruses and extracellular parasites

c. extracellular bacteria and extracellular parasites

d. fungi and extracellular parasites

Solution

Answer:

a. viruses and intracellular bacteria

Explanation:

Normally neutrophil killing is adequate for most bacteria. Intracelluar pathogens are organisms such as viruses and certain bacteria which live inside host cells. Viruses and intracellular bacteria are resistant to killing by neutrophils. Immunity to these organisms is dependent on activating aggressive killing mechanisms in macrophages, which are distinct fromnormal bacteriocidal killing in neutrophils. Such pathogens are not visible to B-cells. All the B-cell can observe is the outside of the host cell, which will look like self. So dofferent mechanism of immune response is needed to kill the viruses and intracellular bacteria.