1. lack of blood plasma proteins and tissue fluid retention/abdominal

1. lack of blood plasma proteins and tissue fluid retention/abdominal bloating/swollen
2. kwashiorkor/marasmus develops;
3. poor growth and development (among children);
4. (often) mental retardation;
5. lethargic/little interest in surroundings
6. wasting of muscle / thin muscles;
cause: [1 max]
1. a genetic variation/mutation;
change in gene coding for tyrosine hydroxylase;
consequences: [1 max]
2. results in a failure to metabolize phenylalanine into tyrosine;
3. results in high levels of ketones in the blood and urine;
4. results in mental retardation/brain damage;
diagnosis: [1 max]
5. can be made by a simple blood test for the level of phenylalanine;
6. diagnosis can be made shortly after birth;
3 max
1. may lead to obesity (which is risk factor for many health problems); NOT weight gain
2. (obesity leads to) increased risk of coronary heart disease/gall bladder
3. disease/high blood pressure/diabetes/excess strain on joints; Accept CHD
4. may lead to increase in blood cholesterol/low density lipoprotein/LDL/
lipid levels;
5. deposits impede blood flow / cause diameter of blood vessel to decrease /
atherosclerosis / degeneration of artery walls;
6. health consequences depend on type of fat ingested — high saturated fat;
3 max
4. (a)
1. e.g. cod liver oil / fish liver oil / oily fish (accept correctly
2. named example) / egg yolk / fortified cereal / ONE named
3. dairy product (i.e. milk/cheese/ yoghurt)
Allow any two sources for the mark. Reject fish alone.
IB Questionbank Biology
1. UV light/sunlight on skin causes chemical production of vitamin D;
2. UV too low in winter in high latitudes;
3. vitamin D stored in liver so can make enough to last severalmonths/through winter;
4. UV light can damage skin and cause skin cancer so exposure needs to be limited;
5. use of sun-block will inhibit vitamin D production;
6. covering skin with clothing prevents UV reaching skin;
Accept reference to cultural/religious customs.
3 max
1. There are cis-unsaturated (isomers) or trans-unsaturated (isomers fatty acids)/
cis-unsaturated hydrogen atoms are bonded on the same side of carbon-carbon double
bond and trans the hydrogen atoms are bonded on the opposite side. ;
2. There are saturated or unsaturated fatty acids, saturated fatty acids have NO double
bonds between carbon atoms and unsaturated have one or more double bonds between
carbon atoms;
3. There are monounsaturated or polyunsaturated;
4. The difference between monounsaturated and polyunsaturated have to do with the
location and the number of the double bonds between carbon atoms;
5. Fatty acids can have short chain or long chain;
minerals are usually elements whereas vitamins are compounds;
minerals are inorganic while vitamins are organic;
iodine deficiency can lead to goitre / mental retardation;
iodine is necessary for thryoxine production;
dietary supplementation usually through iodized salt;
cost to supplement is minimal but cost of deficiency is high;
few foods rich in iodine / lack of marine food in diet can lead to deficiency; 3 max
IB Questionbank Biology
(a) (i) Asian [1]
(ii) 11.5 (%) (allow answers in the range of 11 (%) to 12 (%)) [1]
(NOTE: question is worded awkwardly but if students give both 24.5 % and
11.5 % do not give credit)
1. all ethnic groups show range (very high, high and normal) of albumin levels;
2. greatest frequency of very high levels of albumin found in Pacific Islander patients/
European ancestry patients have lowest frequency of very high levels of albumin;
3. greatest frequency of high levels of albumin in Indigenous Australian/European ancestry
patients / lowest frequency of high levels of albumin in Pacific Islander patients;
4. European ancestry patients have highest frequency of normal levels of albumin / Indigenous
Australian/Pacific Islander patients have lowest frequency of normal levels of albumin; [3
1. European ancestry patients have highest/higher frequency of kidney failure but more than
half/a large percentage have a normal level of albumin;
2. Indigenous Australian patients have lower frequency of kidney failure but higher levels of
3. it would be better to test for both kidney failure and albumin levels; [2 max]
IB Questionbank Biology