Question

Ingestion in sponge is by

• A. Pinacocytes
• B. Archaeocytes
• C. Trophocytes
• D. Choanocytes

Answer 1

The correct option is D Choanocytes

A. Pinacocytes are the flattened cells that form the outer layer or dermal epidermis of body wall of sponges. This outer layer is also called as pinacoderm.

B. Archaeocytes are the undifferentiated embryonic amoebocytes with blunt pseudopodia and large nucleus, showing totipotency. These cells play important role in the regeneration of sponges.

C. Trophocytes are the cells in which digestion of food takes place. These cells are also called as nurse cells.

D. Choanocytes, also called as collar cells, are the specialised flagellated cells that form the gastral epidermis of inner layer of body wall of sponges. This inner layer is also called as choanoderm.

Ingestion in sponges occurs by choanocytes. These cells take up the food particles which are transported to food vacuoles and digestion occurs.

So, the correct answer is 'Choanocytes'.