Answer:
Apicomplexans can be described as parasites which can cause diseases such as malaria inside the host cell. These organisms are known to evolve from the green algae. The remnant chloroplast present in them is used for various drug therapy studies. Their chloroplast can be used to test for various antibiotics and herbicides. This is because their chloroplast has evolutionary similarities with chloroplasts present in other organisms such as the cyanobacteria.