Learning Objectives

13.2.1 Describe the mechanisms organisms use for defending themselves against parasites.

13.2.2 List the mechanisms that parasites use to circumvent host defenses.

As we saw in Chapter 12, carnivores and herbivores exert strong pressure on their food organisms, and vice versa. The same is true of parasites and their hosts: hosts have ways to protect themselves against parasites, and parasites have countermeasures to circumvent host defenses.