Answer: iron.
- A iron
- B copper
- C zinc
- D magnesium
Correct answer: A. iron
Explanation: Each haemoglobin molecule contains iron, which binds oxygen.
A single ECG cycle: the P wave marks atrial depolarisation (contraction signal), the large QRS complex marks ventricular depolarisation, and the T wave marks ventricular repolarisation (recovery) before the next cycle begins.
Concept context
Blood, lymph, the heart, the cardiac cycle, blood pressure, and ECG. High NEET weightage.