Using a capillary tube, a layer of organism suspension is placed over a layer of Group A Streptococcus antiserum. If the two are homologous, a precipitin ring will appear
A) in the area of postzone. B) in the area of prozone.
C) in the zone of equivalence. D) throughout the tube.
Question 2
Diphtheria had been controlled for over 30 years in the Soviet Union. After the Soviet Union was disbanded, cases of diphtheria increased to epidemic proportions in the New Independent States of the Former Soviet Union. This is an example of a/an
A) opportunistic infection. B) focal infection.
C) emerging infection. D) reemerging infection.
