Which of the following is NOT an example of an internal parasite?

Ticks are considered external parasites rather than internal parasites. Internal parasites live inside the host organism, typically in the digestive system, bloodstream, or other internal environments. Examples of internal parasites include worms, flukes, and protozoa, which all inhabit the internal systems of their hosts and can cause various health issues.

Worms, including roundworms and tapeworms, reside in the intestines and often interfere with nutrient absorption. Flukes are flatworms that can inhabit the liver or other organs, causing damage and dysfunction. Protozoa are single-celled organisms that can also live inside the host and disrupt normal bodily functions. In contrast, ticks, which are arachnids, attach to the exterior of a host and feed on its blood, categorizing them as ectoparasites. This distinction clarifies why ticks do not belong to the group of internal parasites.