Lack of oxygen in water forced certain Devonian fishes to develop air-breathing organs. Some left the water and colonized the land; descendants of others are today's remarkable air-breathing species ...

This unsettling sensation, known as Dyspnoea, is commonly referred to as “air hunger.” It’s a symptom characterised by breathlessness, chest tightness, or difficulty breathing, and it ...

Limewater can be used to detect carbon dioxide. Breathing in through the mouthpiece draws air from the atmosphere in through tube A. Breathing out through the mouthpiece bubbles exhaled air ...