Instructions: Given a scientific passage and an answer, generate a question for the given answer.
Input: Passage: Many human diseases are caused by protists. Most of them are caused by protozoa. They are parasites that invade and live in the human body. The parasites get a place to live and nutrients from the human host. In return, they make the host sick. Examples of human diseases caused by protozoa include giardiasis and malaria. Answer: protozoa
Output:
Giardiasis and malaria are diseases caused by what organism?