What is an example of a helminth?

Ascaris lumbricoides is indeed an example of a helminth, specifically a type of roundworm that infects the intestines of humans. Helminths are multicellular parasitic organisms commonly known as worms, and they include various groups such as nematodes (roundworms), cestodes (tapeworms), and trematodes (flukes). Ascaris lumbricoides is one of the most prevalent helminthic infections worldwide, especially in areas with poor sanitation and hygiene.

In contrast, Giardia lamblia is a protozoan parasite and commonly causes gastrointestinal infections but does not fall under the category of helminths. Plasmodium falciparum is another protozoan, known as the causative agent of the most severe form of malaria, which again is distinct from helminths. Lastly, Entamoeba histolytica is also a protozoan, responsible for amoebic dysentery. Thus, while the other options are all pathogenic microorganisms, they are not classified as helminths.