Question

Human have acquired immune system
that produces antibodies to neutralise
pathogens. Still innate immune system
is present at the time of birth because
it
1) is very specific and uses different
macrophages
2) produces memory cells for mounting
fast secondary response
3) has natural killer cells which can
phagocytose and destroy microbes.
4) provides passive immunity

Answer 1

Answer:

Both humoral and cell mediated responsesare essential for antiviral defense. The contribution of each varies, depending on the virus and the host. Antibodies generally bind to virus particles in the blood and at mucosal surfaces, thereby blocking the spread of infection.

Answer 2

Explanation:

All living things are subject to attack from disease-causing agents. Even bacteria, so small that more than a million could fit on the head of a pin, have systems to defend against infection by viruses. This kind of protection gets more sophisticated as organisms become more complex.

Multicellular animals have dedicated cells or tissues to deal with the threat of infection. Some of these responses happen immediately so that an infecting agent can be quickly contained. Other responses are slower but are more tailored to the infecting agent. Collectively, these protections are known as the immune system. The human immune system is essential for our survival in a world full of potentially dangerous microbes, and serious impairment of even one arm of this system can predispose to severe, even life-threatening, infections.