Entamoeba histolytica cysts have _________ nuclei

The correct option is 1-4.

Entamoeba histolytica is an anaerobic parasitic protozoan that infects the human gastrointestinal tract. The life cycle of Entamoeba histolytica consists of two main stages: the trophozoite stage (active, feeding stage) and the cyst stage (infective, resistant stage).

During the process of encystation (the transition from a trophozoite to a cyst), a single-nucleated trophozoite undergoes nuclear division. Specifically, the nucleus undergoes mitosis twice, resulting in a succession of nuclear stages. As the cyst matures, it progresses from a uninucleate stage (containing 1 nucleus) to a binucleate stage (containing 2 nuclei), and finally to a mature tetranucleate stage containing 4 nuclei. Therefore, depending on the stage of maturity, the cysts of Entamoeba histolytica can contain anywhere from 1 to 4 nuclei.