question_answer

(a) Draw a diagram of an excretory unit of human kidney and label the following Bowman's capsule, glomerulus, collecting duct and renal artery. (b) Write the important function of structural and functional unit of kidney. (c) Write any one function of an artificial kidney. Or (a) Draw a schematic representation of transport and exchange of oxygen and carbon dioxide during transportation of blood in human beings and label on it. Lung capillaries; Pulmonary artery to lungs Aorta to body; Pulmonary veins from lungs. (b) What is the advantage of separate channels in mammals and birds for oxygenated and deoxygenated blood?  

Answer:

(a) The excretory unit of human kidney is nephron. Its diagram is given below                                                    (3) (b) Nephron takes part in filtration, reabsorption and selective secretion to form urine.                                 (1) (c) Artificial kidneys helps in removal of toxins, relieve uraemia and remove wastes in patients with damaged kidneys.                                                                    (1) Or (a) (b) It is necessary to separate oxygenated and deoxygenated blood in mammals and birds, because they need high energy and large amount of oxygen. The separation of oxygenated and deoxygenated blood provides high oxygen supply to the organs.              (2)