What is the name for a parasitic worm, such as a tapeworm or leech?

The term "helminths" specifically refers to parasitic worms, including organisms like tapeworms and leeches. Helminths are a diverse group of invertebrate animals that often cause diseases in their hosts. These organisms can be classified into three main groups: trematodes (flukes), cestodes (tapeworms), and nematodes (roundworms).

In this context, tapeworms belong to the cestodes category, while leeches, although primarily known for their blood-feeding behavior, can also be classified as a type of annelid worm that can act as a parasite. Understanding helminths is important in health science because they can significantly impact human health, leading to malnutrition, digestive problems, and various other health issues.

The other options listed refer to different types of organisms. Protozoa are single-celled organisms, bacteria are unicellular microorganisms that can be beneficial or pathogenic, and fungi are a separate kingdom of organisms that include yeasts and molds. Each of these categories has distinct characteristics and implications in health science but do not include the parasitic worms defined as helminths.