Final answer:
Water and nutrients enter a sponge through the incurrent pores, and water and waste exit through the osculum. This process supports all major sponge body functions, including feeding, gas exchange, and waste excretion.
Step-by-step explanation:
In a sponge, water and nutrients enter through the incurrent pores, and water and waste exit through the osculum. Sponges are simple multicellular organisms that filter feed by pumping water through their bodies. Water flows into the sponge through many tiny openings called ostia, which lead to the spongocoel, a large central cavity. Here, specialized cells called choanocytes trap food particles. Amebocytes then distribute these nutrients throughout the sponge. Gas exchange and excretion occur by diffusion as water flows through the sponge. After the water has passed through the spongocoel, it exits through the osculum, carrying away waste products.