Question

Oxygen gas is essential for living beings why​

Answer 1

Oxygen is essential for respiration because the body uses it to 'burn' food molecules. Animals take in oxygen when inhaling and give off carbon dioxide when exhaling.

Oxygen makes up almost 21% of the total gases in air, with most of the remaining gas being physiologically inert nitrogen. Although we inhale 21% oxygen, a person's exhaled breath contains about 16%.

This means that the human body only uses about one quarter of the O2 inhaled, leaving sufficient available for rescue breaths. This is why rescue breathing works - it can supply a non breathing patient with enough oxygen to support life.

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