Essential Biology 6.4 Gas Exchange
Student Name:
Due Date:
Candidate Number:
1. Define the following:
Ventilation
Movement of air into and out of the lungs.
Gas exchange
Cell respiration
Deoxygenated
Oxygenated
2. Explain the need for ventilation in humans.
Size
Humans are large, land-based organisms that cannot exchange gas sufficiently with the
air through diffusion alone. A central ventilation system allows gases to be exchanged
with the blood and carried around the body to the cells that require it.
Oxygen
Carbon dioxide
Concentration gradient
3. Deduce the number of membranes an oxygen molecule must
pass through in order to enter an erythrocyte.
Ms. Fargo
Stephen Taylor
Bandung International School
Essential Biology 6.4 Gas Exchange
Due Date:
Candidate Number:
Student Name:
4.
Label the features of the alveoli and describe how they are adapted for their function.
a.
b.
Many invaginations and millions of alveoli – large surface area
c.
Moist membranes.
d.
Membranes only one cell thick.
5. Label this diagram of the human ventilation system.
a. Trachea
b.
c.
d.
e.
Also don’t forget to be able to draw and label a magnified alveolus.
Practice these drawings on paper – you might need them in the exam!
Ms. Fargo
Stephen Taylor
Bandung International School
Essential Biology 6.4 Gas Exchange
Due Date:
Candidate Number:
Student Name:
6. Explain the method of ventilation of the lungs.
Feature
Inhalation
External intercostal
muscles
Contract, pulling ribcage
up and out.
Exhalation
Internal intercostal
muscles
Diaphragm
Abdominal muscles
Lung volume
Pressure in lungs
Decreases, sucking air
into the lungs.
Data-based question practice, from the IB Biology QuestionBank CDRom.
7. A major requirement of the body is to eliminate carbon dioxide (CO2). In the body, carbon
dioxide exists in three forms: dissolved CO2, bound as the bicarbonate ion, and bound to
proteins (e.g. haemoglobin in red blood cells or plasma proteins). The relative
contribution of each of these forms to overall CO2 transport varies considerably
depending on activity, as shown in the table below.
CO2 Transport in Blood Plasma at Rest and During Exercise
Rest
Exercise
Arterial
Venous
Venous
mmol I–1 blood
mmol I–1 blood
mmol I–1 blood
dissolved CO2
0.68
0.78
1.32
bicarbonate ion
13.52
14.51
14.66
0.3
0.3
0.24
14.50
15.59
16.22
7.4
7.37
7.14
Form of transport
CO2 bound to protein
Total CO2 in plasma
pH of blood
[Source: Geers and Gros, Physiological Reviews (2000), 80, pages 681–715]
Ms. Fargo
Stephen Taylor
Bandung International School
Essential Biology 6.4 Gas Exchange
Student Name:
Due Date:
Candidate Number:
(a) Calculate the percentage of CO2 found as bicarbonate ions in the plasma of venous
blood at rest.
(1)
(b) (i) Compare the changes in total CO2 content in the venous plasma due to exercise.
(1)
8. (ii) Identify which form of CO2 transport shows the greatest increase due to exercise.
(1)
9. (c) Explain the pH differences shown in the data.
(3)
(Total 6 marks)
Ms. Fargo
Stephen Taylor
Bandung International School
Essential Biology 6.4 Gas Exchange
Due Date:
Candidate Number:
Student Name:
Works Cited
1. Allott, Andrew. IB Study Guide: Biology for the IB Diploma. s.l. : Oxford University Press, 2007. 978-019-915143-1.
2. Mindorff, D and Allott, A. Biology Course Companion. Oxford : Oxford University Press, 2007. 978099151240.
3. Clegg, CJ. Biology for the IB Diploma. London : Hodder Murray, 2007. 978-0340926529.
4. Campbell N., Reece J., Taylor M., Simon. E. Biology Concepts and Connections. San Fransisco :
Pearson Benjamin Cummings, 2006. 0-8053-7160-5.
5. Taylor, Stephen. Science Video Resources. [Online] Wordpress, 2010.
http://sciencevideos.wordpress.com.
6. Burrell, John. Click4Biology. [Online] 2010. http://click4biology.info/.
7. IBO. Biology Subject Guide. [Online] 2007. http://xmltwo.ibo.org/publications/migrated/productionapp2.ibo.org/publication/7/part/2/chapter/1.html.
Self Assessment:
Essential Biology
Criterion
Presentation &
Organisation
Academic
Honesty
Objective 1
understanding
Objective 2
understanding
Objective3
understanding
Logic, notation,
mathematical
working
Further research
Assessment
Complete (2)
Partially complete (1)
NA
Complete and neat. All command terms
highlighted, tables and diagrams well presented.
Sources cited using the CSE (ISO 690 numerical)
method, with Works Cited section complete and
correct.
All answers for the following command terms
Most answers for the following command terms
correct:
correct:
Define
Draw
Label
List
Measure State
Most answers for the following command terms
All answers for the following command terms correct:
correct:
Annotate Apply
Calculate Describe Distinguish Estimate Identify
Outline
Most answers for the following command terms
All answers for the following command terms correct:
correct:
Analyse Comment Compare Construct Deduce Derive Design Determine Discuss
Evaluate
Explain Predict
Show Solve
Sketch Suggest
Answers are presented in a logical and concise
manner. SI units used most times, with correct
NA
unit symbols and definitions of terms. All
mathematical working shown.
Evidence is apparent of research and reading
beyond the textbook and presentations to find
correct answers to challenging questions. If any
NA
questions are unanswered, this criterion scores
zero.
NA
Total (max 10):
Ms. Fargo
Stephen Taylor
Bandung International School
Self
MrT