GED Science Practice 2025 - Free GED Science Practice Questions and Study Guide

Malaria is caused by sporozoan parasites belonging to the Plasmodium genus. The life cycle of these parasites involves transmission through the bite of infected female Anopheles mosquitoes, which inject the parasites as sporozoites into the bloodstream of a host. Once inside the human body, these sporozoites migrate to the liver, where they mature and reproduce before re-entering the bloodstream to infect red blood cells. This cycle leads to the symptoms associated with malaria, such as fever, chills, and flu-like illness.

The other options do not accurately represent the cause of malaria; molten rock in the earth's crust pertains to geological processes, agranulocytic leukocytes refer to a type of white blood cell that does not relate to malaria, and while white blood cells are part of the immune response against infections like malaria, they do not cause the disease itself. Therefore, sporozoan parasites are the correct answer, as they are the direct causative agents of malaria.