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Describe the effects of excessive consumption of alcohol: reduced self-control, depressant, effect on reaction times, damage to liver and social implications
1 Answer Explain that the cholera bacterium produces a toxin that causes secretion of chloride ions into the small intestine, causing osmotic movement of water into the gut, resulting in diarrhoea, dehydration and loss of ions from the blood
1 Answer Explain the importance of a clean water supply, hygienic food preparation, good personal hygiene, waste disposal and sewage treatment in controlling the spread of cholera (details of the stages of sewage treatment are not required)
1 Answer Describe the role of the mosquito as a vector of disease
1 Answer Describe that a pathogen may be transmitted: (a) through direct contact, including through blood or other body fluids (b) indirectly, including from contaminated surfaces or food, from animals, or from the air
1 Answer Describe a pathogen as a disease-causing organism
1 Answer List the components of blood as red blood cells, white blood cells, platelets and plasma
1 Answer Describe the transfer of substances between blood in capillaries, tissue fluid and body cells
1 Answer State the functions of the components of blood: (a) red blood cells – oxygen transport (b) white blood cells – antibody production by lymphocytes and engulfing pathogens by phagocytes (c) platelets – clotting by converting soluble fibrinogen to insoluble fibrin to prevent blood loss and the entry of pathogens (d) plasma – transport, limited to: blood cells, ions, glucose, amino acids, hormones, carbon dioxide, urea, vitamins and plasma proteins
1 Answer Explain how the structure of arteries, veins and capillaries is related to the pressure of the blood that they transport
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Sourav Pan
Sourav Pan
Sourav Pan
Sourav Pan
Sourav Pan
Sourav Pan
Sourav Pan