Question

Why One should breathe by nose and never by mouth?Concise Biology Class IX By H.S. Vishnoi CHAPTER 18-HYGIENEf

Answer 1

it is because nose prevent the entering of some amount of dust and bacteria but mouth can't

Answer 2

One should breathe through nose and not by mouth because the dust particles are entraped only by the hair present in the nostrils, also the air inhaled is warmed by the blood vessels in the nose, which is not the case when you breathe through mouth.