Question

Choose the correct route of the flow of water inside a sponge.

• A. Ostia $\to$ Spongocoel $\to$ Osculum $\to$ Exterior
• B. Spongocoel $\to$ Ostia $\to$ Osculum $\to$ Exterior
• C. Osculum $\to$ Spongocoel $\to$ Ostia $\to$ Exterior
• D. Osculum $\to$ Ostia $\to$ Spongocoel $\to$ Exterior
  

Answer 1

The correct option is A Ostia $\to$ Spongocoel $\to$ Osculum $\to$ Exterior

Water canal system is a characteristic feature of phylum Porifera. The body of the poriferans have pores called ostia. The body has only one opening called the osculum. There is a continuous water movement from the exterior to the interior of the body of the poriferans. Water flows through the ostia into the spongocoel and goes out through the osculum. This helps in food gathering, exchange of gases and removal of waste.