Biology · 2001 · November · Paper 3 · SL · TZ2 · Markscheme

MARKSCHEME November 2001 BIOLOGY Standard Level Paper 3 12 pages N01/410/S(3)M A INTERNATIONAL BACCALAUREATE BACCALAURÉAT INTERNATIONAL BACHILLERATO INTERNACIONAL Option A – Diet and Human Nutrition A1. (a) Award [1] for any two of the following fat / saturated / unsaturated; cyanocobalamin / vitamin ; 12B pantothenic acid; energy; carbohydrate; riboflavin / 2B; pyridoxin / 6B; tocopherol; cholesterol; [1 max] (b) both are low in carbohydrates / pantothenic acid / tocopherol / unsaturated fats; both are high in protein / retinol / thiamin / niacin / folic acid; diet A is high in ascorbic acid / fibre, diet B is low; diet B is high in energy / fat / cholesterol / riboflavin / niacin / cyanocobalamin, diet A is low; [3 max] [2 max] (c) Award [1] for each diet from the following. diet A: weight loss due to lack of energy; diet A: pernicious anaemia (or any of the symptoms of it); diet A: high levels of folic acid may mask the initial symptoms of pernicious anaemia; diet B: lack of fibre may lead to problems in the large intestine or even to colon cancer; diet B: lack of ascorbic acid may lead to scurvy (or any of the symptoms of it); diet B: excess of fat / cholesterol may lead to heart disease (or similar); diet B: excess of fat may lead to overweight or obesity; diet A/B: lack of pantothenic acid may cau se fatigue / numbness / tingling of hands and feet; note: dietary deficiencies have not been described for insufficient intake of tocopherols due to lack of documented evidence in humans. A2. (a) Award [1] for any two of the following. cell membranes; energy reserve; can be remodelled to make steroids / hormones; insulation; protection; myelin sheath; [1 max] (b) ( unit required for mark) [1] 100 16 66 - 67 g24 ×= – 3 – N01/410/S(3)M A