Question

Opening of osculum is regulated partly in cells

• A. Myocytes
• B. Porocytes
• C. Archaeocytes
• D. Chaonocytes

Answer 1

Answer: (A)

Myocytes

A. Myocytes are modified contractile amoebocytes arranged around the osculum. They guard and regulate the osculum i.e. they work as sphincter.

B. Between the pinacocytes in the pinacoderm, a number of large conical, on open tube like peculiar cells called porocytes are present. The tunnel in each porocytes is called an ostium by which sea water enters into the spongocoel.

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

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

Hence, opening of osculum is regulated partly in myocytes.

So, the correct answer is 'Myocytes'.