Which of the following is a definitive host for Plasmodium species?

The definitive host for Plasmodium species is the Anopheles mosquito. In the lifecycle of Plasmodium, these mosquitoes play a critical role by facilitating sexual reproduction of the parasite. When an infected female Anopheles mosquito bites a human, it can transmit the sporozoites of Plasmodium into the bloodstream of the host. Inside the mosquito, the Plasmodium undergoes sexual reproduction, leading to the formation of new sporozoites that will eventually be transmitted to another human.

Humans serve as the intermediate host where asexual reproduction occurs, leading to the symptoms associated with malaria, but the Plasmodium does not complete its lifecycle in humans. Therefore, while humans are important in the transmission of malaria, it is the Anopheles mosquito that is the definitive host in which the sexual phase of Plasmodium takes place.