(a) Draw a sectional view of the human heart and label on it – Aorta, Right ventricle and Pulmonary veins. (b) State the functions of the following components of transport system: (i) Blood (ii) Lymph -Biology
Answer.(a) (b) The functions of blood and lymph are as follows: (i) BloodOxygen is transported by the blood to the tissues of the body for the breakdown of digested food.Carbon dioxide is transported to the lungs by the blood plasma.The digested and absorbed nutrients are transported by blood to the tissues. Nitrogenous wastes are transported to the kidneys.It regulates the body temperature and maintains the pH of the body tissues.It transports various hormones from one region to another and bring about the coordination.It maintains water balance to constant level.The lymphocytes produce antibodies against the invading antigens and protect from diseases.It helps in rapid healing of wounds by forming a clot at the site of injury. (ii) LymphIt cleans the cellular environment.It returns proteins and tissue fluids to the blood (drainage)It provides a pathway for the absorption of fats and fat-soluble vitamins into the bloodstream.It defends the body against disease. 38.(a) Draw a labelled diagram of the respiratory system of human beings with diaphragm at the end of expiration. (b) List four conditions required for efficient gas exchange in an organism. Answer.(a) (b) (i) A large surface area over which exchange can take place. (ii) A concentration gradient without which nothing will diffuse. (iii) A thin surface across which gases diffuse. (iv) Warm conditions.