Discuss the limitations of using antigen concentration to deduce the path of infection. be sure to refer to the workings of the human immune system.

The limitation of using antigen concentration in order to determine the path of infection is that if one has been vaccinated for the infection, then his or her immune system has already produced the antibodies against the antigens. Thus, it can generate an inaccurate result, in the case of ELISA test.  

An ELISA test also known as an enzyme-linked immunosorbent assay refers to a test, which finds and calculates the number of antibodies in the blood. The test is beneficial in finding the antibodies associated with a certain kind of infectious conditions.  

the cladogram shown here shows similarities and differences among several classes of vertebrates. anatomically, the four have limb structure as their common ancestor. we might separate the mammals from the other three classes because they a) divergent; do not lay eggs b) identical; are warm-blooded c) varied; a four chambered heart d) homologous; have mammary glands

age range would be the answer