Answer: Oxygen (via haemoglobin).
- A Carbon dioxide, dissolved directly in plasma
- B Nitrogen, an inert gas with no carrier protein
- C Oxygen (via haemoglobin)
- D Hydrogen, released during cellular respiration
Correct answer: C. Oxygen (via haemoglobin)
Explanation: RBCs contain haemoglobin which binds and transports oxygen from lungs to tissues. CO<sub>2</sub> is also transported but mostly in plasma.
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.