| Date | May 2017 | Marks available | 3 | Reference code | 17M.2.SL.TZ2.6 |
| Level | Standard level | Paper | Paper 2 | Time zone | Time zone 2 |
| Command term | Describe | Question number | 6 | Adapted from | N/A |
Question
Describe the structure and function of starch in plants.
Outline the production of carbohydrates in photosynthesis.
Discuss the processes in the carbon cycle that affect concentrations of carbon dioxide and methane in the atmosphere and the consequences for climate change.
Markscheme
Structure:
a. «starch» is a polysaccharide/is composed of glucose molecules
b. contains amylose which is a linear/helical molecule
c. contains amylopectin which is a branched molecule
Function:
d. storage of glucose/energy in plants
e. storage form that does not draw water
a. light is absorbed by chlorophyll
OR
chlorophyll absorbs more red and blue light
b. «absorbed» light energy is converted to chemical energy
c. some of the energy is used for production of ATP
d. water molecules are split/photolysis
e. produces oxygen «as waste product»/hydrogen/NADPH
f. plants absorb/fix CO2 «from air or water»
g. ATP/energy is needed to produce carbohydrates/starch
a. CO2 is produced from respiration in organisms/combustion of biomass/fossil fuels
b. CH4 is produced by anaerobic respiration of biomass/«methanogenic» bacteria
c. CH4 is oxidized to CO2 and water
d. CO2 is converted into carbohydrates/organic compounds by autotrophs/producers/photosynthesis
e. CO2 can be converted to calcium carbonate/fossilized into limestone
f. «partially» decomposed organic matter/biomass can be converted into peat/coal/oil/gas/fossil fuels
g. CO2 and CH4 are both greenhouse gases/increase greenhouse effect
h. both absorb long-wave radiation from the earth and retain the heat in the atmosphere
i. increased CO2 concentrations in the atmosphere correlate with increased combustion of fossil fuels
j. rising average global temperatures correlate with more greenhouse gases in the atmosphere
k. cattle production/rice paddy/defrosting of tundra increase CH4 in the atmosphere
OR
increasing CO2 leads to acidification of marine/aquatic environments
l. the global temperature increase influences/disrupts climate patterns
OWTTE
Examiners report
Syllabus sections
- 18M.2.SL.TZ1.2a.i: Distinguish between the structure of amylose and the structure of amylopectin.
- 17N.1.HL.TZ0.05: Which of the molecules contain peptide bonds or are sugar molecules?
- 16N.1.SL.TZ0.7: The diagram shows a molecular structure. Which type of molecule is shown? A. Amino acidB....
- 20N.1.HL.TZ0.8: The table shows the mass of different types of fat in some foods. Which oil would be least...
- 17M.1.HL.TZ1.8: What type of molecule is shown in this diagram? A. Trans saturated fatty acid B. Cis...
-
17N.1.SL.TZ0.08:
The Framingham heart study was an observational study that went on for 20 years. The following data were produced.
[Source: adapted from Gillman et al., Margarine intake and subsequent coronary heart disease in men.
Epidemiology, 1997 Mar; 8(2): 144–9]Which conclusion can be drawn, based on these data?
A. It is better to eat margarine than to eat butter.
B. The more margarine consumed, the greater the incidence of coronary heart disease.
C. Butter is a natural product whereas margarine is hydrogenated vegetable oil that leads to coronary heart disease.
D. Margarine causes more heart related deaths than butter.
- 18M.2.SL.TZ1.2a.ii: Suggest the reason for cellulose passing undigested through the human gut.
- 18N.2.SL.TZ0.2b: Outline one reason for humans being unable to digest cellulose.
- 20N.3.SL.TZ0.1a: State the BMI of a person of mass 80 kg and 1.80 m in height.
-
18M.1.HL.TZ1.7:
Which fatty acid would occur in a trans fat?
[Source: © International Baccalaureate Organization 2018]
- 19N.2.HL.TZ0.4a.ii: State the reason cis and trans fatty acids are said to be unsaturated.
- 19M.1.SL.TZ1.6: What type of molecule is formed by the chemical reaction shown in the diagram? A....
- 17M.1.SL.TZ2.27: The bacterium Neisseria gonorrhoeae causes infections related to the human reproductive...
-
20N.2.SL.TZ0.1c:
Calculate, showing your working, the percentage change in mean cholesterol level after one week on the study diet.
. . . . . . . . . . . . . . . . . . . .%
-
18M.1.SL.TZ2.7:
Which molecule represents a lipid?
[Source: © International Baccalaureate Organization 2018]
-
21N.1.HL.TZ1.9:
The diagrams show how monosaccharide molecules are joined to form chains in two polysaccharides.
[Source: Amelse, J. Achieving Net Zero Carbon Dioxide by Sequestering Biomass Carbon. Preprints 2020, 2020070576
(doi: 10.20944/preprints202007.0576.v1). Fig SI9. Distributed under a Creative Commons CC BY license Attribution
4.0 International (CC BY 4.0), https://creativecommons.org/licenses/by/4.0/.]Using the diagram and the table, which diagram and monosaccharide represent glycogen?
- 19N.1.SL.TZ0.7: Which of the molecules shown would be most suitable for long-term energy storage in humans?
-
18M.1.SL.TZ1.8:
Which type(s) of fatty acid in the diet is/are positively correlated with an increased risk of coronary heart disease?
I. Saturated
II. Trans unsaturated
III. Cis unsaturated
A. I only
B. I and II only
C. II only
D. II and III only
- 17M.1.SL.TZ1.21: Cladograms can be created by comparing DNA or protein sequences. The cladogram on the left is...
-
21M.1.SL.TZ1.13:
The table shows the range and classification of body mass index (BMI) values, as shown in the nomogram.
[Source: © All rights reserved. Canadian Guidelines for Body Weight Classification in Adults. Health Canada, 2003. Adapted and reproduced with permission from the Minister of Health, 2021.]
What is the approximate reduction in body mass that a person of height 155cm and mass 95kg would have to lose to reach normal body mass?
A. 10kg
B. 22kg
C. 36kg
D. 54kg
-
20N.3.SL.TZ0.1b:
Explain how measurement of BMI could help to assess whether a person has an increased risk of type II diabetes.
-
20N.2.SL.TZ0.1b:
Distinguish between the two diets.
-
20N.2.SL.TZ0.5a:
Draw a molecular diagram of alpha-D-glucose.
-
19N.1.SL.TZ0.9:
Using the nomogram, what is the minimum mass at which a woman of height 165 cm would be considered overweight?
[Source: Copyright 1978, George A. Bray. Used by permission]
A. 72
B. 67
C. 64
D. 61
-
21M.1.SL.TZ2.8:
The chart classifies individuals according to their height and mass.
[Source: InvictaHOG, 2006. Body mass index chart. [chart online] Available at: <https://commons.wikimedia.org/w/index.php?curid=1208092> [Accessed: 4 April 2019].]
Based on the information provided, which individual is most at risk of diseases associated with the accumulation of excessive body fat?
- 17N.2.SL.TZ0.05c: Compare and contrast cis-fatty acids and trans-fatty acids.
- 17M.1.SL.TZ1.6: A polymer of alpha-D-glucose found in plants has mostly 1,4 linkages and some 1,6 linkages....
- 19M.2.HL.TZ1.4c: Outline how the structure of cellulose makes it suitable as a component of cell walls.
- 21M.2.HL.TZ2.3e: Once the germinated bean grows above the ground, state the process used by the bean in the...
- 21M.1.SL.TZ1.10: Which molecule is depicted in the diagram? A. A saturated fatty acid B. An unsaturated...
- 17M.2.HL.TZ1.1f.ii: Suggest a reason for the greater expression of the gene for the urea transporter after an...
- 18N.2.SL.TZ0.2a.ii: Cellulose is the most abundant organic polymer on Earth. Describe the structure of cellulose.
-
20N.1.SL.TZ0.7:
The chart shows ranges of body mass index (BMI) for children and teenagers.
[Source: Centers for Disease Control and Prevention, About Child & Teen BMI. Available at:
https://www.cdc.gov/healthyweight/assessing/bmi/childrens_bmi/about_childrens_bmi.html.]A 9-year-old boy has a height of 120 cm and weighs 28.8 kg. What weight category is he in according to his BMI?
A. Underweight
B. Healthy
C. Overweight
D. Obese
-
20N.2.SL.TZ0.1e:
The hypothesis made before the study was that saturated fats in the diet affected the risk of coronary artery blockage and diabetes. Using all the data in question 1, evaluate whether this hypothesis is supported by the study.
-
21M.2.SL.TZ2.5a:
Describe the structure of starch.
-
21M.2.HL.TZ2.3d:
Broad beans are rich in starch and cellulose. Compare and contrast the structure of starch and cellulose.
- 17M.2.SL.TZ1.1c: Estimate how much smaller drilled oysters raised in seawater at a high CO2 concentration were...
- 18N.2.SL.TZ0.2c: Explain the advantages of having both lipid and carbohydrate as energy stores in the human body.
-
19M.1.SL.TZ2.7:
The diagram shows two polysaccharides, formed from condensation of many glucose molecules.
[Source: © International Baccalaureate Organization 2019]
What are the names of X and Y?
- 21M.1.HL.TZ2.7: Which organic molecules may contain the element sulphur? A. Proteins B. Carbohydrates C....
- 19M.1.SL.TZ2.12: The diagram shows a type of fatty acid. What type of fatty acid is shown? A. Trans...
- 17M.2.SL.TZ1.6b: Distinguish between the structures of the different types of fatty acids in food.
-
16N.1.HL.TZ0.7:
Olive oil may reduce the risk of coronary heart disease. What is/are the compound(s) responsible for the health benefits of olive oil?
I. Cis unsaturated fatty acids
II. Trans unsaturated fatty acids
III. Saturated fatty acidsA. I only
B. I and II only
C. II and III only
D. I, II and III - 21M.1.HL.TZ2.6: The diagram shows part of a molecule. What is the molecule? A. Amylose B. Cellulose C....
- 21M.1.SL.TZ1.8: What distinguishes cellulose from glycogen and starch? A. Only cellulose is found in...
-
20N.2.SL.TZ0.1a:
Comment on the total energy content of the two diets.
- 16N.1.SL.TZ0.6: Which type of reaction is the breakdown of starch into sugars? A. DenaturationB. ReductionC....
