| Date | November 2019 | Marks available | 6 | Reference code | 19N.3.HL.TZ0.23 |
| Level | Higher level | Paper | Paper 3 | Time zone | TZ0 / no time zone |
| Command term | Explain | Question number | 23 | Adapted from | N/A |
Question
Explain how ventilation rate is changed during vigorous physical exercise.
Markscheme
a. exercise increases the rate of cellular respiration ✔
b. increases production of CO2 ✔
c. increased CO2 causes increased acidity in blood
OR
decrease pH ✔
d. chemoreceptors in aorta/carotid artery/medulla oblongata detect change in pH ✔
e. impulse/signal/message to breathing centre
OR
impulse/signal/message to medulla oblongata ✔
f. impulse/signal/message to to diaphragm for more frequent contraction
OR
impulse/signal/message to intercostal muscles for more frequent contraction ✔
g. increase ventilation rate for more gas exchange ✔
h. long term effects of increased lung surface area
OR
vital capacity ✔
i. training decreases ventilation rate over time ✔
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.TZ1.22:
Explain how an increase in cell respiration in a tissue causes increased release of oxygen by hemoglobin in the tissue.
- 18M.3.HL.TZ2.21b: Suggest how high altitude could lead to polycythemia.
- 18M.3.HL.TZ2.21c: Suggest how changes in hemoglobin could help humans become better adapted to living at high...
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17N.3.HL.TZ0.23:
Discuss high altitude training for athletes.
- 17M.3.HL.TZ1.21a.i: Outline the main changes in the lungs that occur in patients with emphysema.
- 17M.1.SL.TZ1.10: The graph shows the effect of increasing the substrate concentration on the rate of an...
- 17M.3.HL.TZ2.19b.iv: Sometimes hyperkalemia occurs as a body tries to respond to low blood pH. State the normal...
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20N.3.HL.TZ0.23d:
Describe what happens to the hemoglobin from old or damaged red blood cells that are broken down.
- 18M.3.HL.TZ2.21a: From the diagram, deduce the effect of the disease polycythemia on the proportion of...
-
20N.3.HL.TZ0.23b:
State two modes of transport of carbon dioxide in blood.
1.
2.
- 17M.3.HL.TZ1.21a.ii: State a treatment for emphysema.
-
20N.3.HL.TZ0.23a:
Using the graph, explain the Bohr shift.
-
17M.3.HL.TZ2.19b.v:
Explain how low blood pH causes hyperventilation (rapid breathing).
- 20N.3.HL.TZ0.23c: State the effect of carbon dioxide in blood on the rate of ventilation.
-
19M.3.HL.TZ1.24a:
The electron micrograph shows a section through an alveolus showing blood in a capillary.
[Source: © International Baccalaureate Organization 2019]
Identify the cells found at X and Y.
X:
Y:
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19M.3.HL.TZ1.24b:
Explain, with the aid of an annotated diagram, how physical exercise affects the affinity of hemoglobin for oxygen.
- 17M.3.HL.TZ1.21b.ii: Explain how the increase in CO2 concentration affects the release of oxygen to respiring cells.
- 17M.3.HL.TZ1.21b.i: An increase in metabolic activity results in greater release of CO2 into the blood. On the...
- 19N.2.HL.TZ0.1h: Using all the data, discuss whether inoculating mice with the antigen to B. burgdorferi could...
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19M.3.HL.TZ2.23:
Discuss the significance of the oxygen dissociation curves for adult hemoglobin and fetal hemoglobin.
