alternative concepts
TRANSCRIPT
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Misconception onrespiration and breathing
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In everyday language,
breathing and respiration can be synonymous. When we enter
the academic area of science, however, terms become moredistinctive.
To review our definition of breathing:
Breathing is the active, mechanical process some animals use to
draw in oxygen rich-air and to
push out carbon dioxide-rich air. This is accomplished through therespiratory system, which
consists of such structures as the lungs, the trachea, and the
diaphragm.
What is respiration? In science, respiration refers to the process
where chemical energy is
converted to other forms of energy (e.g., heat and motion energy in
humans). This occurs in
cells of organisms (living things).
Clear so far? Ok, now it becomes
complicated
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Respiration is the same for most
organisms: it's a slow form of burning.
Think about what happens when carbon
contained in substances such as wood, candle
wax, or paper burnsIt combines with oxygen, releasing energy
(light, sound, heat, motion).
Respiration is the same
process: oxygen and high energy compounds containing
carbon combine, releasing heat and
motion energy (needed to carry on life functions).
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Most organisms require oxygen for
respiration,but oxygen is not
obtained through respiration.
Only some animals have respiratory
systems and, therefore, breathe, but
all organisms respire.
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In the early grades, the focus should be on energy. Questions
can include:
What are activities that living things do
that need energy How do living things get the energy they
need for these activities
In later grades, respiration can become the specific focus.
What is the process of respiration
How can we distinguish between the respiratory
system and respiration
Copyright 2002 by the Capital Region Science Education Partnership
This material is based upon work supported by the National Science Foundation under Grant No. 991186.
Any opinions,
findings, and conclusions or recommendation expressed this material are those of the author(s) and do not
necessarily
reflect the view of the National Science Foundation.
www.crsep.org
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However, many question setters
(teachers) set questions which show
confusion between these two
processes.
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In the syllabus, differentiation is made between
respiration and breathing, that is,Breathing refers to the process that brings about an
exchange of gases between the organism and its
environment; and
Respiration refers to the process that releases energy
from food substances in living cells
At the primary level the distinction between
breathing as a physical process and respiration as achemical process is not made.
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Example Question 1 illustrates the confusion
in the question setter's mind. The intended
answer is Option 1- lungs. The question stem
refers to respiration whereas the options
provided and the intended answer are
specifically parts concerned with breathing or
the process of that brings about gaseousexchange between organisms and their
environment.
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One possible cause of this particularmisconception could be the universal use ofthe term "respiration" to refer to aspectsconcerning the breathing system - particularly
in human biology and medicine where thenostrils, windpipe, lungs together with themechanical actions of the diaphragm and ribcage are referred to as the respiratory systemand lung diseases such as bronchitis andpneumonia are termed respiratory ailments.
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An incomplete understanding of breathing isshown in Example Question 2 which is also takenfrom the P4 level. In this example the intended
answer is option 4. However, what is breathedout is not just carbon dioxide. The correctconcept is that the air that is breathed in isrelatively rich in oxygen (about 21%) and poor in
carbon dioxide (about 0.03) whilst the air that isbreathed out is poorer in oxygen (about 16%) butricher in carbon dioxide (about 4%).
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REFERENCES
1) Bar, V., & Travis, A. (1991). Children's views concerning phase
changes. Journal of Research in Science Teaching, 28(4), 363-382.
2) Boo, H. K. (1995). A burning issue for Chemistry Teachers. Teaching and
Learning, 13(2), 52-60. Singapore : National Institute ofEducation.
3) Boo, H.K. (2003). Primary science assessment in the context of ThinkingSchools Learning Nation vision. Teaching and Learning, 24(2), 131-140.
4) Boo, H.K. (2006). Primary science assessment item setters' misconceptions
concerning the state changes of water.Asia-Pacific Forum on Science
Learning and Teaching , 7 (1), Article 6 (June 2006). Available
at http://www.ied.edu.hk/apfslt/v7_issue1/boohk/
5) http://www.ied.edu.hk/apfslt/v8_issue1/boohk/boohk5.htm#ref