Answer: haemoglobin.
- A haemoglobin
- B chlorophyll
- C melanin
- D carotene
Correct answer: A. haemoglobin
Explanation: Haemoglobin in red blood cells gives blood its red colour.
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.