Final answer:
The Paramecium protist has a contractile vacuole for osmoregulation and a large macronucleus that contains multiple gene copies, which is central to its cellular function and asexual reproduction.
Step-by-step explanation:
The protist Paramecium have a contractile vacuole in the stalk and a large macronucleus that contains multiple copies of its genes. Paramecium have a distinctive cellular structure with two types of nuclei: the macronucleus for asexual reproduction and metabolic functions, and the micronucleus for sexual reproduction. The contractile vacuole plays a role in osmotic regulation, expelling excess water from the cell to maintain salt and water balance.