Question

Copper containing respiratory pigment is seen in phylum:

• A. Echinodermata
• B. Mollusca
• C. Aschelminthes
• D. All of the above

Answer 1

The correct option is B Mollusca

Haemocyanin occurs in both the arthropods and molluscs, and is almost certainly of independent origin although it is possible that ultimately both are derived from a very ancient copper protein. The two copper atoms, reversibly bind to a single oxygen molecule (O${}_2$). They are second only to hemoglobin in frequency of use as an oxygen transport molecule. Unlike the hemoglobin in red blood cells found in vertebrates, hemocyanins are not bound to blood cells but are instead suspended directly in the hemolymph. Oxygenation causes a color change between the colorless $C{u}^{+}$ deoxygenated form and the blue $C{u}^{++}$ oxygenated form.

Hence the correct option is B