The definitive host for Toxoplasma gondii is __________.


a. humans
b. cats
c. birds
d. mosquitoes

Verified step by step guidance

1. Understand the concept of a definitive host: it is the organism in which a parasite reaches sexual maturity and reproduces sexually.
2. Recall the life cycle of Toxoplasma gondii, a protozoan parasite known for infecting various warm-blooded animals.
3. Identify which organism serves as the definitive host where Toxoplasma gondii undergoes sexual reproduction.
4. Recognize that cats (family Felidae) are the definitive hosts for Toxoplasma gondii, as the parasite completes its sexual cycle in their intestinal cells.
5. Conclude that among the options given, the correct answer is 'cats' because humans, birds, and mosquitoes are intermediate or incidental hosts, not definitive hosts.

Key Concepts

Definitive Host

The definitive host is the organism in which a parasite reaches sexual maturity and reproduces. For Toxoplasma gondii, identifying the definitive host is crucial because it completes its life cycle only within this host.

Toxoplasma gondii Life Cycle

Toxoplasma gondii is a protozoan parasite with a complex life cycle involving both sexual and asexual stages. The sexual reproduction occurs exclusively in the intestines of the definitive host, while asexual stages can occur in intermediate hosts.

Role of Cats in Toxoplasma Transmission

Cats are the definitive hosts for Toxoplasma gondii, where the parasite undergoes sexual reproduction. They shed oocysts in their feces, which can infect other animals and humans, making cats central to the parasite's transmission cycle.