Question

a person recovers from a viral infection and is then exposed to the same virus a decade later but does not get sick. which of the following best explains this rapid, effective secondary response? memory t cells from the original infection quickly produced a large army of cytotoxic t cells to destroy the virus. the initial activation of b cells was sufficient to provide lifelong protection without t cell involvement. helper t cells from the first infection were still circulating and managing the immune system. regulatory t cells immediately suppressed the virus before it could infect any cells. a person gets dust in their eye, and their eye begins to water, washing the particles out. which two first - line - of - defense mechanisms are best demonstrated here? biological and chemical (good bacteria and acid). mechanical and chemical (tears washing away particles and enzymes in tears). chemical and chemical (enzymes and zinc). mechanical and biological (cilia and harmless bacteria).

Explanation:

For the first question, memory T - cells from the original infection can quickly produce cytotoxic T - cells to destroy the virus during a secondary exposure, which is a key aspect of the secondary immune response. For the second question, tears washing away particles is a mechanical defense, and the enzymes in tears are a chemical defense.

Answer:

1. Memory T cells from the original infection quickly produced a large army of cytotoxic T cells to destroy the virus.
2. Mechanical and Chemical (tears washing away particles and enzymes in tears)