2. Topic Outline
There are three parts to this assessment:
1. Classroom teaching/learning – Introduction to Gas Exchange
2. Student research and rewriting Google Doc– Completed at HOME or in STUDY
using google doc template, must be printed and brought into class for the
report writing.
3. Report writing– in class under test conditions with the use of your printed out
research google doc information you.
NOTE:
Resubmissions are for minor omissions with no extra time for further research or
teaching and for those on the boarder of grade boundaries only.
3. Content
Ecological Niche
Adaptations
Respiration and Gas Exchange
Diffusion of Gases
Gas Exchange Surfaces and Structures
Mammals
Fish
Insects
Paraphrasing
Referencing
4.
5. Ecological Niche
Where an organism lives, what it eats, what eats it, when it is
active, adaptations it has to survive
Realised niche
Where the organism is actually found due to limiting factors – competition,
lack of resources
Fundamental niche
Where the organism could potentially be found
6.
7. Adaptations
Aid in the survival of an organism in its
ecological niche
There are 3 types of adaptations:
Structural - eg. Alveoli – increases the surface
area and are thin
Behavioural - eg. Swimming against the current
– moves more oxygenated water past gills in fish
Physiological - eg. an ability to lower metabolic
rates during exposed periods to minimise oxygen
consumption.
9. Cellular respiration requires O2 and produces CO2 :
C6H12O6 + 6O2 6CO2 + 6H2O
This is a universal process
• Gas exchange provides a means of supplying an
organism with O2 and removing the CO2
glucose + oxygen carbon dioxide + water
Respiration and Gas Exchange
11. THE SOURCE OF OXYGEN
Air
21% oxygen
Gets thinner at higher altitudes
easy to ventilate (get O2 in and CO2 out)
Water
amount of oxygen varies but is always much less than air
even lower in warmer water
harder to ventilate
12. GAS EXCHANGE SURFACES
Gases move by diffusion from areas of high concentration to areas
of low concentration.
Diffusion is greater when:
• the surface area is large
• the distance travelled is small
• the concentration gradient is high
Gas exchange also requires a moist surface
• O2 and CO2 must be dissolved in water to diffuse across a membrane
15. GAS EXCHANGE SURFACES
Therefore, an efficient gas exchange surface will…
have a large surface area
provide a small distance for gases to diffuse across
be moist
…and will be organised or operate in a way that maintains a
favourable concentration gradient for the diffusion of both gases.
A circulatory system may operate in
tandem with the gas exchange system
to maintain the concentration gradient
16. Depends on:
the size of the organism
where it lives – water or land
the metabolic demands of the
organism – high, moderate or low
STRUCTURE OF THE GAS EXCHANGE SURFACE
18. Gas Exchange in Insects
Air tubules (trachea & tracheoles)
throughout the body which open to the
environment via spiracles
Body muscles contract to move air
Tracheoles deliver oxygen to every respiring
cell
Ends of tracheoles are moist
Inefficient system results in insects being
limited in size
21. Gas Exchange in Fish
Gills have a very large surface area:
four arches with flat filaments with lamellae folds
Gills are thin-walled and in close contact with
water: short distance for diffusion
Gills have a very high blood supply to bring
CO2 and carry away O2 dark red colour
Counter current exchange creates large
diffusion gradient
Opening and closing of operculum ventilates
gills
Gills are moist: fish live in water!
25. Large surface area
many tiny alveoli
area as big as a tennis court in humans!
Short distance for diffusion
• alveoli and capillary walls only one cell thick
• capillaries pressed against alveoli
Moist
• wet lining of alveolus (surfactant)
• system internal to reduce water loss by evaporation
Gas Exchange in Mammals
Maintaining a concentration gradient
• air (with depleted O2 and excess CO2) is exhaled replaced with fresh
inhaled air
• blood (having lost CO2 and been enriched with O2) returns to heart to
get pumped around body
28. Gas Exchange in Mammals
http://education-portal.com/academy/lesson/gas-exchange-function-of-the-
pulmonary-surfactant-nature-of-the-respiratory-surface.html#transcript
29. Bibliography
A bibliography is an alphabetical list of all sources
you consult or use for projects, reports, research,
etc., including–
books
magazines
newspapers
CD-ROMs
websites
interviews
encyclopaedias
video clips
images (pictures)
30. Why do we need a bibliography?
To acknowledge our sources
show where we found the information
To give our readers information to
identify and consult our sources
To make sure our information is accurate
To show academic honesty
31. Cheating
This is called plagiarism (using another person’s words, pictures
or ideas without giving them credit).
To avoid plagiarism, you need to give credit to your sources by
citing them in a bibliography.
32. Paraphrasing
To “borrow” from a source without plagiarizing you need to rewrite the information
or paraphrase it.
A paraphrase is...
your own version of essential information and ideas expressed by someone else,
presented in a new form.
one legitimate way (when accompanied by accurate documentation) to borrow
from a source.
Paraphrasing is a valuable skill because...
it is better than quoting information from an undistinguished passage.
it helps you control the temptation to quote too much.
the mental process required for successful paraphrasing helps you to grasp the
full meaning of the original.
33. 6 Steps to Effective Paraphrasing
1. Copy and paste the section of work you want to paraphrase onto the Google doc
prepared for you. Record the correct APA reference below it.
2. Reread the original passage until you understand its full meaning.
3. Set the original aside, and write your paraphrase in the section of the Google
doc prepared for you.
4. Check your version with the original to make sure that it accurately expresses all
the essential information in a new form.
5. Use quotation marks to identify any unique term or phraseology you have
borrowed exactly from the source.
34. Example of Paraphrasing
The original passage:
Students frequently overuse direct quotation in taking notes, and as a result they overuse quotations in the
final [research] paper. Probably only about 10% of your final manuscript should appear as directly quoted
matter. Therefore, you should strive to limit the amount of exact transcribing of source materials while
taking notes. Lester, James D. Writing Research Papers. 2nd ed. (1976): 46-47.
A legitimate paraphrase:
In research papers students often quote excessively, failing to keep quoted material down to a reasonable
level. Since the problem usually originates during note taking, it is essential to minimize the material
recorded verbatim (Lester 46-47).
An acceptable summary:
Students should take just a few notes in direct quotation from sources to help minimize the amount of
quoted material in a research paper (Lester 46-47).
A plagiarized version:
Students often use too many direct quotations when they take notes, resulting in too many of them in the
final research paper. In fact, probably only about 10% of the final copy should consist of directly quoted
material. So it is important to limit the amount of source material copied while taking notes.
35. Exercises
Directions: On a separate piece of paper, write a paraphrase of each of the following
passages. Try not to look back at the original passage.
1. "The Antarctic is the vast source of cold on our planet, just as the sun is the source of our
heat, and it exerts tremendous control on our climate," [Jacques] Cousteau told the camera.
"The cold ocean water around Antarctica flows north to mix with warmer water from the
tropics, and its upwellings help to cool both the surface water and our atmosphere. Yet the
fragility of this regulating system is now threatened by human activity." From "Captain
Cousteau," Audubon (May 1990):17.
2. The twenties were the years when drinking was against the law, and the law was a bad
joke because everyone knew of a local bar where liquor could be had. They were the years
when organized crime ruled the cities, and the police seemed powerless to do anything
against it. Classical music was forgotten while jazz spread throughout the land, and men like
Bix Beiderbecke, Louis Armstrong, and Count Basie became the heroes of the young. The
flapper was born in the twenties, and with her bobbed hair and short skirts, she symbolized,
perhaps more than anyone or anything else, America's break with the past. From Kathleen
Yancey, English 102 Supplemental Guide (1989): 25.
