The host in which sexual reproduction takes place is called the

• A. Commensal
• B. Intermediate host
• C. Vector
• D. Definitive host

Answer: (D)

In parasitology, the host where the parasite reaches sexual maturity and produces eggs or offspring is the definitive host. That’s the stage of the life cycle where sexual reproduction occurs, completing the sexual part of the cycle. The intermediate host, by contrast, harbors larval or asexual stages and does not support the parasite’s sexual reproduction. A vector is the means of transmission between hosts and is not defined by where sexual reproduction happens, though in some cycles the vector can also be the site of sexual reproduction. An example helps: Taenia solium has humans as the definitive host where the adult tapeworm reproduces; pigs are the intermediate host with larval forms. For malaria, the mosquito is the definitive host because sexual reproduction occurs there.