Question

bacteria on the skin and in the gi tract may be part of what barrier?
a chemical barrier
b biological barrier
c mechanical barrier
d bacterial barrier

Explanation:

Bacteria on the skin and in the GI - tract are living organisms that contribute to the body's defense against pathogens. They interact with the host and other microorganisms, which classifies them as part of a biological barrier. Chemical barriers involve substances like enzymes and acids, mechanical barriers are physical structures like the skin's surface, and "bacterial barrier" is not a standard term for this context.

Answer:

B. biological barrier