Question

When is the innate immune system activated?

a. Before the adaptive immune system is activated.
b. Before a pathogen has breached a physical barrier.
c. Only during a secondary immune response (i.e. not during a primary immune response)
d. A & B
e. B & C

Answer 1

The correct answer is option (d), as the innate immune system activates before the adaptive system and before a pathogen breaches physical barriers.

Step-by-step explanation:

The innate immune system is activated before the adaptive immune system and before a pathogen has breached a physical barrier. This means that option (d) A & B is the correct answer.

The innate immune response is the body's first line of defense against pathogens and includes barriers like skin and mucus, as well as rapid, non-specific responses such as inflammation and phagocytosis.

It operates from the moment of first exposure to the pathogen and does not require prior sensitization, unlike the adaptive immune response which is more specific and forms memory after an initial exposure.