Question

Which of the following is responsible for red colour of the blood?

• A. Plasma proteins
• B. Haemoglobin
• C. WBC
• D. None of the above

Answer 1

Answer: (B)

Haemoglobin

Hemoglobin (Hb or Hgb ) is an iron-containing protein present in erythrocytes or Red blood cells(RBC) of almost all vertebrates. Each hemoglobin is made up of 4 subunits, 2 alpha subunits and 2 beta subunits. Each subunit surrounds the central heme group that contains iron and binds to one oxygen molecule. The red colour of blood is due to the presence of haemoglobin. The blood cells are red due to the interaction between iron and oxygen. These red cells which contain hemoglobin are responsible for the red colour to the blood.

So, the correct answer is 'Haemoglobin'.