Multiple choice general knowledge science & technology

The main constituent of hemoglobin is

  1. Chlorine

  2. Iron

  3. Calcium

  4. None of these
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Hemoglobin contains four iron atoms (in heme groups), each binding one oxygen molecule. Iron is essential for oxygen transport: without it, hemoglobin cannot function. This is why iron deficiency causes anemia.

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