Final answer:
A flagellated cell that sweeps water through a sponge's body is called a choanocyte. Choanocytes have a single flagellum surrounded by a collar and are responsible for generating water flow through the sponge and capturing food particles.
Step-by-step explanation:
A flagellated cell that sweeps water through a sponge's body is called a choanocyte. Choanocytes are unique to sponges and have a single flagellum surrounded by a collar.
The beating of the flagella from all choanocytes moves water through the sponge and helps trap and digest food particles.