Multiple choice

RBCs are the most numerous and have iron-containing red respiratory pigment called _______.

  1. bilirubin

  2. haemoglobin

  3. fibrinogen

  4. platelets

Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Haemoglobin is the iron-containing protein in red blood cells (RBCs) that binds oxygen for transport. Bilirubin is a waste product of haemoglobin breakdown, while fibrinogen is involved in clotting.