Question

Which one of the following is a collared cell?

• A. Scleroblast
• B. Silicoblast
• C. Chromocyte
• D. Choanocyte

Answer 1

The correct option is D Choanocyte

A. Scleroblasts are the skeleton manufacturing cells in sponges and may be calcoblasts, silicoblasts or spongioblasts.

B. Silicoblasts are the scleroblasts that secrete siliceous spicules.

C. Chromocytes are the pigmented amoebocytes with lobose (thick, bulbous, blunt) pseudopodia.

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

So, the correct answer is 'Choanocyte'.