Final answer:
Protists that have a pellicle are surrounded by cellulose, which is a polysaccharide found in the cell walls of plants and some algae.
Step-by-step explanation:
Protists that have a pellicle are surrounded by cellulose. Cellulose is a polysaccharide found in the cell walls of plants and some algae. It provides structural stability and protection from environmental stresses.