| Date | May 2019 | Marks available | 1 | Reference code | 19M.1.SL.TZ1.7 |
| Level | Standard level | Paper | Paper 1 | Time zone | Time zone 1 |
| Command term | Identify | Question number | 7 | Adapted from | N/A |
Question
Which substance must be transported in the blood by lipoprotein complexes?
A. Cholesterol
B. Oxygen
C. Sodium chloride
D. Amino acids
Markscheme
A
Examiners report
Several teachers expressed doubts in feedback forms about whether lipoprotein complexes are an expected part of the programme. The question was based on the statement ‘Modes of transport of glucose, amino acids, cholesterol, fats, oxygen and sodium chloride in blood in relation to their solubility in water’, which is in 2.2 of the Core. It would be hard to study this without including lipoprotein complexes for transport of fats and cholesterol. Given the health consequences of these substances, it seems an eminently worthwhile area of study. The question was answered correctly by about half of pupils, but because the discrimination index was only moderately good, some of the stronger candidates must have chosen an incorrect answer, probably amino acids.
Syllabus sections
- 17N.1.SL.TZ0.07: Which property of water accounts for its moderating effects on the Earth’s atmosphere? A....
- 17N.2.SL.TZ0.03a: The figure represents a water molecule. Draw a second water molecule to show how bonds can...
- 21M.1.SL.TZ1.12: What is the term for the attraction of water molecules to other water molecules? A. Surface...
- 18M.1.SL.TZ2.8: At room temperature, water is a liquid and methane is a gas. Which molecular property...
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19M.1.HL.TZ1.6:
Water has a specific heat capacity of 4.2 J g–1 K–1 at room temperature, a latent heat of vaporization equal to 2257 J g–1, and a boiling point of 100 °C. What are the specific heat capacity, latent heat of vaporization and boiling point of methane?
[Source: © International Baccalaureate Organization 2019]
- 17N.3.SL.TZ0.01c: Predict the temperature of the water in the cups after 3 hours.
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20N.3.SL.TZ0.3b:
Outline how the carbon dioxide could be removed from the water used to irrigate the plant.
- 22M.2.SL.TZ2.3b.i: Distinguish between the thermal properties of water and methane.
- 17M.1.SL.TZ2.27: The bacterium Neisseria gonorrhoeae causes infections related to the human reproductive...
- 17M.1.SL.TZ1.21: Cladograms can be created by comparing DNA or protein sequences. The cladogram on the left is...
- 22M.2.HL.TZ1.6a: Outline how the properties of water make it an effective coolant for the body.
-
20N.2.HL.TZ0.7a:
Outline how hydrogen bonds form in water.
- 17M.1.HL.TZ2.7: Which can be explained by the solvent properties of water? A. Sodium chloride is transported...
-
17N.3.SL.TZ0.01d:
Explain, with reference to the thermal properties of water, how this experiment helps demonstrate how humans respond to overheating.
- 21M.1.SL.TZ2.7: What property of water accounts for its usefulness as a coolant in sweat? A. High specific...
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17N.3.SL.TZ0.01a:
Calculate the change in temperature in each cup after 20 minutes.
Uncovered:
Covered with wet tissue paper:
-
21N.2.HL.TZ0.7a:
Outline how the properties of water make it an ideal transport medium in plants.
- 19M.1.SL.TZ2.6: Where do hydrogen bonds form? A. Between the slight negative charge of hydrogen and slight...
- 17M.2.HL.TZ1.1f.ii: Suggest a reason for the greater expression of the gene for the urea transporter after an...
- 17M.2.HL.TZ2.3a: Outline the properties of water molecules that permit them to move upwards in plants.
- 16N.1.SL.TZ0.8: Which properties explain the ability of water to dissolve solutes? I. Polarity of water...
- 21N.1.SL.TZ0.7: What is the benefit to living organisms that water has a high specific heat capacity? A....
- 17M.2.SL.TZ1.1c: Estimate how much smaller drilled oysters raised in seawater at a high CO2 concentration were...
- 18M.1.SL.TZ1.7: Researchers have developed a skin patch which can detect and measure very small...
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17N.3.SL.TZ0.01b:
State two conditions that must be the same for each cup at the start of the experiment.
- 19N.1.SL.TZ0.8: What is a property of water? A. Water has a low specific heat capacity so large increases in...
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17N.2.SL.TZ0.03b:
Water has important solvent properties. Explain these properties using an example to illustrate your answer.
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18M.2.HL.TZ1.6c:
Hydrogen bonds can exist both within and between molecules in living organisms and have an impact on their structure and function. Explain the importance of hydrogen bonding for living organisms.
