In which host does the sexual cycle of Toxoplasma gondii occur?

In which host does the sexual cycle of Toxoplasma gondii occur?

• A. Dog
• B. Cat
• C. Pig
• D. Mouse

Answer: (B)

Sexual reproduction of Toxoplasma gondii happens only in the definitive hosts, which are felines. In the cat’s intestinal lining, the parasite undergoes sexual development and produces oocysts that are shed in the feces. Those oocysts then sporulate in the environment and can infect other animals. Other hosts listed, like dogs, pigs, and mice, do not support the sexual cycle; they become infected through asexual stages and serve as intermediate hosts. So, the host where the sexual cycle occurs is the cat.