What life cycle stage of Toxoplasma gondii can be shed by cats?

The correct choice is oocysts. In the life cycle of Toxoplasma gondii, the definitive host is typically the domestic cat. When a cat ingests tissue cysts from infected prey or other sources, the parasite undergoes sexual reproduction in the cat's intestines, leading to the formation of oocysts. These oocysts are then shed in the cat's feces.

Oocysts are significant because they are the environmentally resistant stage of the parasite, capable of surviving in harsh conditions outside the host. Upon shedding, oocysts can contaminate soil, water, and food sources, posing a risk for transmission to other animals and humans.

Cysts, on the other hand, are found in the tissues of intermediate hosts (including humans) and are not shed by cats. Trophozoites are an active, feeding stage of specific protozoa that primarily exist in the host's tissues and are not a stage associated with shedding in the case of T. gondii. Sporozoites are the infectious forms that develop within the oocysts but they are not shed directly by the cats. The ability to shed oocysts is a crucial aspect of the transmission cycle of Toxoplasma gond