Question

question 16
which of the following is not a pathogen?
a foreign material
b bacteria
c viruses
d leukocytes

Explanation:

Pathogens are agents that cause disease. Bacteria and viruses are well - known pathogens. Foreign material can sometimes act as an antigen but not all are pathogens. Leukocytes are white blood cells which are part of the immune system and help fight pathogens, not pathogens themselves.

Answer:

D. leukocytes