Q. A large proportion of oxygen is left unused in the human blood even after its uptake by the body tissues. This O₂
A) Helps in releasing more O₂ to the epithelial tissues
B) Acts as a reserve during muscular exercise
C) Raises the pCO₂ of blood to 75 mm of Hg
D) Is enough to keep oxyhaemoglobin saturation at 96%
Explanation
[Solution from source] Each 100 mL of oxygenated blood delivers only about 5 mL of O₂ to the tissues at rest, so venous blood remains largely saturated. This unused oxygen acts as a reserve that can be released when muscular activity increases the demand. Answer (2).
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.