Today in the NDA/CDS 2 2026 Biology live class, we discussed two important topics of human physiology: the digestive system and the respiratory system. Both systems are essential for maintaining life and are frequently asked in defence examinations such as NDA and CDS. Understanding these topics not only helps students score well in exams but also builds a strong foundation in basic biology. The class focused on the structure, functions, and important processes associated with both systems along with exam-oriented facts and concepts.
The digestive system is responsible for the breakdown of food into simpler substances that can be absorbed and utilized by the body. We studied the major organs of the digestive system including the mouth, oesophagus, stomach, small intestine, large intestine, liver, pancreas, and gall bladder. Special emphasis was given to the role of digestive enzymes such as salivary amylase, pepsin, trypsin, and lipase. The process of digestion, absorption, assimilation, and egestion was explained in detail. Important NDA/CDS facts such as the liver being the largest gland, the small intestine being the main site of absorption, and bile juice secretion were also discussed during the session.
The respiratory system was the second major topic covered in today’s class. This system helps in the exchange of gases by supplying oxygen to the body and removing carbon dioxide. We discussed the organs involved in respiration including the nose, pharynx, larynx, trachea, bronchi, lungs, and alveoli. Students learned about the mechanism of breathing, inhalation and exhalation, and the role of the diaphragm. The importance of haemoglobin in oxygen transport and the function of alveoli as the respiratory surface of the lungs were also explained. Various exam-based concepts and objective questions related to respiration were discussed to strengthen conceptual clarity.
Overall, today’s Biology live class was highly informative and exam-oriented for NDA/CDS 2 2026 aspirants. The digestive and respiratory systems are among the most important chapters in human physiology and are regularly asked in competitive defence examinations. Students were encouraged to revise diagrams, learn important enzymes and functions, and practice previous year MCQs for better retention. The class successfully built a strong conceptual understanding that will help students in both objective questions and general scientific awareness.
