| Date | May 2017 | Marks available | 4 | Reference code | 17M.3.SL.TZ1.21 |
| Level | Standard level | Paper | Paper 3 | Time zone | Time zone 1 |
| Command term | Discuss | Question number | 21 | Adapted from | N/A |
Question
Discuss the causes and treatments of phenylketonuria.
Markscheme
Causes:
a. phenylketonuria is an inherited / genetic condition / caused by a mutation
b. enzyme phenylalanine hydroxylase/PAH not present/deficient
c. phenylalanine is an essential amino acid
d. inability to convert phenylalanine into tyrosine / phenylalanine builds up in the body
Treatment:
e. requires diet rich in tyrosine «supplements»
f. low in phenylalanine
g. monitor blood phenylalanine levels
h. monitor growth rates / intellectual development
Examiners report
Syllabus sections
- 22M.1.HL.TZ1.40: What is the role of HCG in early pregnancy? A. It prevents the degeneration of the corpus...
- 18M.3.HL.TZ1.19a.ii: Suggest one limitation of the information about vitamins shown on this label.
- 18M.3.SL.TZ2.15d: The recommended daily intake of vitamin D is 15 μg. This student consumed just 4 μg. State...
- 18M.3.HL.TZ2.19b: State one factor, other than BMI, that increases the risk of CHD.
-
18M.3.HL.TZ2.19a:
Using the graph, discuss the hypothesis that a high BMI in adolescence is more dangerous than a high BMI in adulthood.
- 17M.3.HL.TZ2.18: Describe a method that could be used to measure the energy content of a sample of food.
- 18M.3.HL.TZ1.19a.i: State the importance of including vitamins in our diet.
- 16N.3.SL.TZ0.17d: Suggest, with reasons, which milk would be recommended for someone with osteomalacia.
- 19M.3.SL.TZ1.15b.i: Outline the relationship shown in the graph.
- 18M.3.SL.TZ1.19: Discuss the causes and consequences of malnutrition in humans.
- 17M.1.SL.TZ1.10: The graph shows the effect of increasing the substrate concentration on the rate of an...
- 16N.3.SL.TZ0.17b: State one function of sodium in the diet.
- 16N.3.HL.TZ0.19b: List features that would increase a person’s risk of developing diabetes.
- 19N.3.HL.TZ0.19a: Distinguish between essential and non-essential amino acids.
- 19M.3.SL.TZ1.15b.ii: Suggest reasons for this relationship.
- 20N.3.SL.TZ0.16b: Outline the reason for ascorbic acid being described as an essential nutrient in the diet of...
- 19N.3.HL.TZ0.19b: Using the data from the tables, suggest a reason for the differences in lysine concentration...
- 19M.3.HL.TZ1.22b: The energy value calculated for avocado was 750 kJ 100 g–1. The actual energy value of...
-
16N.3.SL.TZ0.16b:
Explain how the administration of a drug that stimulates the leptin receptors in the hypothalamus could help treat obesity.
- 19M.3.HL.TZ1.22c.i: Avocados are known to be a good source of dietary fibre and contain all the essential amino...
- 19M.3.SL.TZ1.15a: Osteomalacia is a condition that can be caused by Vitamin D deficiency. Outline one effect of...
- 19M.3.HL.TZ2.21a.i: Identify which state had the smallest seasonal change in vitamin D levels.
- 19M.3.SL.TZ2.16a: State the relationship between BMI and age in men.
- 17M.3.SL.TZ1.17a.ii: Deduce the reason for rickets in these infants.
- 17M.3.SL.TZ1.17a.i: Describe the relationship between the maternal blood vitamin D levels and the incidence of...
- 17M.3.SL.TZ2.22: Explain a method to quantify the energy content in food.
- 17M.3.SL.TZ1.17c: Outline the reason for some amino acids being classified as essential amino acids.
- 18M.3.SL.TZ2.15a: Using the bar chart, determine the percentage of the recommended daily target of protein...
- 18M.3.SL.TZ2.15b: Suggest which essential dietary requirement might be missing if insufficient protein is...
- 19N.3.SL.TZ0.16b: Describe how the energy content of food may be measured by combustion.
- 19N.3.HL.TZ0.19c: Explain the consequences of protein deficiency malnutrition.
- 19N.3.HL.TZ0.19e: State one possible cause and one symptom of type II diabetes. Cause: Symptom:
- 17M.3.SL.TZ1.17b: Identify the reason for vitamin D not being considered to be a typical vitamin.
- 18N.3.SL.TZ0.16a: Outline how the data indicate that protein was being used as an energy source.
- 18N.3.SL.TZ0.16c: Discuss whether the mass losses shown in the bar chart could be due to anorexia nervosa.
- 19M.3.HL.TZ2.21a.ii: Suggest one reason why people in Victoria show such a large seasonal change in vitamin D levels.
- 19M.3.SL.TZ1.16a: Outline one consequence for the heart of the eating disorder anorexia nervosa.
- 19M.3.SL.TZ2.16b: Evaluate the data to assess whether a high BMI is a risk factor for the development of diabetes.
- 16N.3.SL.TZ0.17c: Identify, with a reason, which milk provides more energy in a 250 g serving.
- 18N.3.SL.TZ0.16b: Outline the reason for such a high percentage reduction in mass of adipose tissue.
- 19M.3.HL.TZ1.22c.ii: Avocados are known to be a good source of dietary fibre and contain all the essential amino...
- 19M.3.HL.TZ1.22a: Apart from the water temperature, state two other values to be measured at the start of the...
- 19M.3.HL.TZ2.21c: Vitamins and minerals are both essential nutrients. Compare and contrast vitamins and dietary...
- 19M.3.HL.TZ2.21b: Outline one effect of lack of vitamin D.
- 20N.3.SL.TZ0.16a: On the cladogram, label with an M, the point at which a mutation occurred, preventing the...
- 20N.3.SL.TZ0.16d: The apparatus used to measure energy content of food contains some water. Explain how this...
- 16N.3.SL.TZ0.17a: Calculate how many grams of protein should be consumed each day. Working is not required.
-
17N.3.SL.TZ0.19:
Explain the possible health risks of being overweight.
- 19N.3.SL.TZ0.16a: Using the data, discuss the implications for the advice given by dieticians to patients.
- 17M.3.HL.TZ1.21b.ii: Explain how the increase in CO2 concentration affects the release of oxygen to respiring cells.
- 19N.2.HL.TZ0.1h: Using all the data, discuss whether inoculating mice with the antigen to B. burgdorferi could...
- 19N.3.HL.TZ0.19d: List two dietary sources of vitamin D.
-
16N.3.HL.TZ0.19a:
A study was undertaken to determine the most effective method to delay the onset of type II diabetes in high-risk patients. Three groups were given either a placebo (control), a medicine that suppresses glucose production by the liver (anti-diabetic drug) or a lifestyle-modification program (lifestyle). The results for four years are shown in the graph.
Analyse the use of the anti-diabetic drug in delaying the onset of type II diabetes.
-
18M.3.HL.TZ1.19d:
Many animals, including humans, maintain strongly acidic conditions in part of their digestive systems. Explain two benefits of this to the animal.
- 16N.3.SL.TZ0.16a: Identify the increased probability of an obese person having hypertension relative to someone...
-
20N.3.SL.TZ0.16c:
A small box of orange juice contains these details on the side of the package:
[Source: © International Baccalaureate Organization 2020.]
Calculate the volume of juice needed to obtain the recommended daily requirement of vitamin C.
. . . . . . . . . . . . . . . . . . .mL
