Tetranucleated cyst stage is found in Entamoeba histolytica.

Explanation:

Entamoeba histolytica is a parasitic protozoan that causes amoebiasis, which is an infection of the intestines. The life cycle of Entamoeba histolytica involves two stages - the trophozoite stage and the cyst stage.

The trophozoite stage is the active and motile form of the parasite, while the cyst stage is the dormant and infective form. The cyst stage allows the parasite to survive outside the host and spread to new individuals.

During the cyst stage, the nucleus of the parasite undergoes multiple divisions, resulting in the formation of several nuclei within the cyst. In the case of Entamoeba histolytica, the cyst stage is tetranucleated, meaning it contains four nuclei. This is a characteristic feature of this species.

The tetranucleated cyst stage is an important diagnostic feature of Entamoeba histolytica. It can be identified in stool samples during microscopic examination. The cysts are round or oval in shape and contain four nuclei, which can be visualized using special staining techniques.

It is important to differentiate Entamoeba histolytica from other species of Entamoeba, such as Entamoeba coli, which can also be present in stool samples. Entamoeba coli cysts are typically uninucleated or binucleated, while Entamoeba histolytica cysts are tetranucleated.

In conclusion, the tetranucleated cyst stage is found in Entamoeba histolytica, a parasitic protozoan that causes amoebiasis.

It is the infective stage to man & is seen in Entamoeba Histolytica.