'Pathogens' were discovered by

Pheromones are chemicals that are used in animals for:

Assertion: Thick cuticle is mostly present in disease-resistant plants.
Reason: Disease-causing agents cannot grow on cuticle and cannot invade the cuticle.

In which of the following sets are all organisms considered vectors?

Which of the following provides the sites for the interaction of lymphocytes with the antigen, which then proliferate to become effector cells?

Physical barrier = .............. and physiological barrier = .............