Welcome to your CIE AS Transport in mammals In which heart chamber's wall does the electrical initiation of a heartbeat begin? Left auricle Right ventricle Left ventricle Right auricleSelect the correct statement regarding carbon monoxide. Carboxyhaemoglobin is formed when carbon monoxide combines with haemoglobin molecules. Exhaust fumes from cars contain less amounts of carbon monoxide. Haemoglobin does not combine with carbon monoxide readily than it does with oxygen. Treatment for carbon monoxide poisoning involves multiple blood dialysis.Vessels carrying blood away from the heart. Arteries Capillaries Tubules VeinsWhich of the following is not a characteristic of a double circulation? Left side handles oxygenated blood. Presence of 2 atria and 2 completely seperated ventricles. Mixing of oxygenated and deoxygenated blood. Right side handles deoxygenated blood.The 'lub' sound of the heart is caused by the closure of which type of valves? Pulmonary semilunar Atrioventricular Aortic semilunar MitralVessels carrying blood towards the heart. Arteries Tubes Capillaries VeinsWhat are the 3 layers of a heart? a) Endocardium b) Epicardium c) Pericardium d) Myocardium a, b & c a, d & c c, b & d a, d & b The mammalian circulatory system is a ___________. Closed double circulation Systemic circulation Pulmonary circulation Open double circulationSelect the correct statement(s) out of the followin: a)Red blood cells are shaped like a biconvex disc. b)Red blood cells are very small. c)Red blood cells are very flexible. d)Red blood cells have many mitochondria. b, c & d a, b & c b & c only a & d onlyWhich is not an adaptation shown by people living permanently at high altitude? Larger heart, especially the right side Presence of more haemoglobin in blood than usual Different genetical composition Broad chestsSelect the incorrect statement regarding lymphatic system. Lymphatics are tiny, blind-ending vessels, which are found in almost all tissues of the body. The fluid inside lymphatics is called lymph. The valves in the lymph vessel walls are narrow and restricts the movement of large protein molecules. There are lymph nodes at intervals along lymph vessels.