Question

49
spongin is made of... (1 point)
collagen
calcium carbonate
silicon dioxide
mesohyl

Explanation:

Spongin is a proteinaceous substance found in the skeleton of some sponges. Collagen is a type of protein, and spongin is made of a form of collagen. Calcium Carbonate and Silicon Dioxide are inorganic compounds and not the components of spongin. Mesohyl is the gelatinous matrix in sponges, not the component of spongin.

Answer:

A. Collagen