Complex sentence: Some protists are significant pathogens of both animals and plants; for example "Plasmodium falciparum", which causes malaria in humans, and "Phytophthora infestans", which causes potato blight.
Split into simpler sentences: Some protists are significant pathogens of both animals and plants. For example "Plasmodium falciparum" which causes malaria in humans and "Phytophthora infestans" which causes potato blight.