Question

Which of the following statements are true about worms?

Select all that apply

Certain types of worms were once used for bloodletting.

Many worms are parasites with complex life cycles.

Parasitic worms have been used to treat overactive immune systems.

Worm castings improve soil quality.

Answer 1

All four statements are true.

- Certain types of worms were once used for bloodletting — leeches (annelid worms) were widely used historically and are still used in some medical contexts.
- Many worms are parasites with complex life cycles — many helminths (trematodes, cestodes, nematodes) require multiple hosts and stages.
- Parasitic worms have been used to treat overactive immune systems — helminthic therapy (or helminth-derived products) has been investigated to modulate autoimmune and allergic diseases.
- Worm castings improve soil quality — earthworm castings are rich in nutrients and beneficial microbes and enhance soil structure and fertility.