Final answer:
The apicomplexan genera that cause coccidiosis in chickens is Eimeria. Other apicomplexans like Plasmodium and Toxoplasma cause different diseases such as malaria and toxoplasmosis, respectively, but are not responsible for coccidiosis.
Step-by-step explanation:
The apicomplexan genera that cause coccidiosis in chickens is Eimeria. Coccidiosis is an intestinal disease that affects various types of animals, including chickens, and is caused by protozoan parasites of the genus Eimeria. These parasites are part of the larger group of apicomplexans, which are characterized by an apical complex used for invading host cells. Other well-known apicomplexans include Plasmodium, which causes malaria, and Toxoplasma, which causes toxoplasmosis. However, these are not responsible for coccidiosis in chickens. It’s worth noting that cryptosporidiosis and toxoplasmosis are also caused by apicomplexan protozoans, namely Cryptosporidium parvum and Toxoplasma gondii respectively, but they do not cause coccidiosis in chickens.