NCERT Book for Class 11 Biology – (Chapter 17 – Breathing And Exchange of Gases)
Chapter 17 – Breathing And Exchange of Gases
Breathing and Exchange of Gases is an important chapter in Class 11 Biology that explains how humans take in oxygen and remove carbon dioxide from the body. Breathing is a physical process involving inhalation and exhalation, while gas exchange is a physiological process that occurs in the lungs and tissues.
This chapter describes the respiratory system, including the nasal cavity, pharynx, larynx, trachea, bronchi, lungs, and alveoli. The alveoli provide a large surface area for the exchange of oxygen and carbon dioxide through diffusion. It also explains the mechanism of breathing, role of the diaphragm and intercostal muscles, and the transport of gases in blood by hemoglobin.
Key concepts such as oxygen dissociation curve, partial pressure of gases, respiratory volumes and capacities, and regulation of respiration are discussed in detail. This chapter is crucial for understanding human physiology and is highly important for CBSE board exams and NEET preparation.
Breathing and Exchange of gases NCERT












