As your group adds to the graphic, your teacher tells you to add an example for each of the four boxes at the base. Which example would BEST fit under the first box: Physical Barrier?

A) resistance chicken pox either from exposure or vaccine

B) the enzyme lysozyme present in your tears degrades bacteria

C) white blood cells rush to the site of a wound to engulf bacteria

D) exposure to antigens lead to the production of antibodies that mark cells for destruction

Answer: The correct answer is B) the enzyme lysozyme present in your tears degrades bacteria.

Tears are the part of innate immunity, which is one of the two types of immune system (innate and adaptive).

Innate immunity (also called first line of defense) can be described as the generalized defense strategy of individual (that is present from birth).

It includes certain physical and chemical barriers that are always ready to fight and clear pathogen.

For example - Lysozyme (found in tears, saliva, mucus, and breast milk) degrade bacteria by breaking their cell wall and thus prevent infection.

Thus, option B) is the right answer.