The cyst form of Balantidium coli is the infective stage. It…

The cyst form of Balantidium coli is the infective stage. It has one large kidney-shaped macronucleus and one small, round micronucleus. The troph is quite large, measuring 50 to 150 microns in length and 40 to 70 microns in width. What single feature is associated with this organism?