Question

Blood pigment of annelids is
A)Haemoglobin
B)Cyanin
C)Haemanin
D)Haemocyanin

Answer 1

Hint: Annelids are observed to be ringworms. They possess three layers of germ cells and possess a body cavity in between the gut and the outer body wall. The animals of Phylum Annelida are known to exist in marine, terrestrial and freshwater environments, but the presence of moisture or humidity, mostly in terrestrial habitats, is a significant factor in their survival.

Complete answer:
A breathing pigment binds to oxygen and transmits it within the whole body, keeping the organs and tissues oxygenated. When a pigment molecule binds to an oxygen molecule, it assimilates a certain colour of light, and the light that has not been absorbed is shown to us.
As a result, the pigment molecules possess various shades, and so does the blood that takes them. Haemoglobin, hemocyanin, hemerythrin and chlorocruorin are the four most essential respiratory invertebrate pigments.

Now let us find solution from given options:
Haemoglobin : It provides red colour to the blood. It helps to bind with oxygen. It is usually present in human beings. It is also present in earthworms.
Cyanin : It is not a pigment of animals. This pigment is usually present in the plants.
Haemanin : It is a pigment that is usually bluish in colour that is not seen in animals.
Haemocyanin : Haemocyanin is termed as a non-heme copper-containing protein that is observed as a respiratory pigment in certain invertebrate animals which make them to transport oxygen throughout their body. It is a protein that takes oxygen and is present in Annelida.

Hence, the correct answer is option (D)

Note: Hemocyanin is also observed in Arthropods (it is the largest phylum of invertebrates). Although the gross molecular structure of hemocyanin varies a little bit varies, they both have haemoglobin and hemocyanin in the same dioxygen binding centres.