Upload
magda
View
28
Download
1
Tags:
Embed Size (px)
DESCRIPTION
Biology 2.6: Describe diversity in the structure and function of animals. Chapter 21 in Textbook (p210) Achievement Standard 90462 3 Credits. ANIMAL Diversity 1. Learning Intention: Identify 3 animals with different types of gas exchange systems. - PowerPoint PPT Presentation
Citation preview
Biology 2.6: Describe diversity in the structure and function of animals
Chapter 21 in Textbook (p210)Achievement Standard 90462
3 Credits
ANIMAL Diversity 1
Learning Intention:
Identify 3 animals with different types of gas exchange systems.
Define gas exchange, breathing and cellular respiration and explain how they are linked
SUCCESS CRITERIA:
Can Identify 3 animals with different types of gas exchange systems.
Can Define gas exchange, breathing and cellular respiration and explain how they are linked
What is Diversity?
• Diversity: • [dih-vur-si-tee]• noun, plural• 1. the state or fact of
being diverse; difference; unlikeness.
• 2. variety; multiformity.
• 3. a point of difference.
http://www.youtube.com/watch?v=jLuK-EBkcww
3 animals• For each of the animals pictured below, describe their
habitat and their structural, physical and behavioral features
• Is there a relationship between their features / adaptations and their habitat? Discuss.
http://www.youtube.com/watch?v=7798h1siNO8
Terminology• 73774728466• 427 39242643• 273284464
Term My Definition Biological Definition
The difference between the two
Gas Exchange
• “The movement of gases across a membrane”
Why do we need to carry out gas
exchange?
Figure 10.8A
Breathing
Animation
ANIMAL Diversity 2
Learning Intention:
Identify the need for a gas exchange system in multicellular animals
Describe the characteristics of an efficient gas exchange system
SUCCESS CRITERIA:
States the need for a gas exchange system
States the characteristics of an efficient gas exchange sys
GAS EXCHANGE IN ANIMALSWe will be studying the diversity of adaptations for this process in THREE animal groups:
Mammals
Fish
Insects
GAS EXCHANGE SURFACESGases move by diffusion.
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
GAS EXCHANGE SURFACESTo maximise diffusion, an efficient gas exchange
surface will…1.have a large surface area2.provide a small distance for gases to diffuse
across3.be moist4.Maintain a favourable concentration gradient for
the diffusion of both gases.
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
DIVERSITY IS REQUIRED!!!!
Need for a gas exchange system in multicellular animals
PROBLEM•the distance a gas can diffuse is only millimeters•This means single celled and very small organisms can easily exchange gases over their membranes as they have a large surface area compared to their volume•But why cant multicellular organisms?
As multi-cellular organisms get larger, more and more cells will not be in direct contact with the air or will not be near enough to the surface to receive oxygen and expel carbon dioxide through
direct diffusion. They have a low surface area: volume ratio They therefore need a gas exchange system
Conclusions:
• As an organism becomes larger, their volume increases at a faster rate than their surface area. Problems?
Only inactive organisms It would take too could be supported long to reach the
middle of the
organism
• Solutions? Flattened shape OR Specialised exchange surfaces
multicellular animals need a gas exchange system
• Platyhelminthes are flattened—"flatworms." This flattening
makes them very thin and gives them a large ratio of surface area
to volume. • The flatworm's respiratory surface
area is large enough to service its relatively low volume.
An exception: •Many multicellular animals are small enough that they don't require a specialized gas exchange system•Flatworms (phylum Platyhelminthes) have adaptations that eliminate the need for a complex respiratory (and circulatory) system.
Task
1. Do WB p 191, 192
2. Exam Q: • Multicellular animals are large and have made
certain adaptations to ensure their oxygen requirements are met. Explain why they have made these adaptations and the common features of the adaptations
ANIMAL Diversity 3
Learning Intention:
Describe how a moist, thin, large surface area within a gas exchange system is achieved in Insects
SUCCESS CRITERIA:
Label parts of an insects anatomy
Explain gas exchange in insects
Gas Exchange in Insects
• Take your photocopy, and make notes as we move through the process of gas exchange for insects
• The respiratory system of insects (and many other arthropods) is separate from the circulatory system. It is a complex network of tubes (called a tracheal system) that delivers oxygen-containing air to every cell of the body.
• Air enters the insect's body through valve-like openings in the exoskeleton.
• These openings (called spiracles) are located along the thorax and abdomen of most insects -- usually one pair of spiracles per body segment.
• Air flow is regulated by small muscles within each spiracle
• After passing through a spiracle, air enters a longitudinal tracheal trunk
• It diffuses throughout a branching network of tracheal tubes that subdivide into smaller and smaller diameters and reaches every part of the body.
• At the end of each tracheal branch, a special cell (the tracheole) provides a thin, moist surface for the exchange of gasses
• Oxygen is dissolved in liquid at the tracheole and then diffuses into the cytoplasm of an adjacent cell.
• At the same time, carbon dioxide diffuses out of the cell and, eventually, out of the body through the tracheal system.
Tracheoles
Trachea Spiracle
Task
• WB page 196
ANIMAL Diversity 4Learning Intention:
Describe how a moist, thin, large surface area within a gas exchange system is achieved in mammals
SUCCESS CRITERIA:
Label parts of a mammal anatomy
Explain gas exchange in mammals
DO NOW:
Draw an insect and label parts
of its respiratory system
Human Respiratory System
Figure 10.1
Breathing (ventilation): air in to and out of lungs. 2 parts – Inspiration (breathing in) and Expiration (breathing out)
External respiration: gas exchange between air and blood
Internal respiration: gas exchange between blood and tissues
Cellular respiration: oxygen use to produce ATP, carbon dioxide as waste
Four Respiration Processes
Components of the Lower Respiratory Tract
Figure 10.3
MAMMAL LUNGS: BREATHINGTwo lungs ventilated by movement
of diaphragm and ribs
MAMMAL LUNGS: STRUCTURE
Rubber cast of human lungs
MAMMAL LUNGS: STRUCTURE
• Air enters via trachea (windpipe)
• Trachea branches into two bronchi (one bronchus to each lung)
• Bronchi branch into bronchioles
System of tubes (held open by rings of cartilage) allow air to flow in and out of lungs
MAMMAL LUNGS: STRUCTUREMany alveoli at the end of the bronchioles• walls made of flat cells; only one cell thick• each alveolus lined with moisture• surrounded by capillary network carrying blood
GAS EXCHANGE IN MAMMALS
Gas exchange animation
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• system internal to reduce water loss by evaporation
ENHANCING THE EFFICIENCY OF MAMMAL LUNGS
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
Task
• WB p 197-199
• http://bcs.whfreeman.com/thelifewire/content/chp48/4802002.html
ANIMAL Diversity 5Learning Intention:
Describe how a moist, thin, large surface area within a gas exchange system is achieved in fish
SUCCESS CRITERIA:
Label parts of a fish anatomy
Explain gas exchange in fish
DO NOW:
Draw a mammals respiratory
Structures (include lungs AND
close up of alveoli). Use red and blue
to show Blood oxygenation http://newswatch.nationalgeographic.com/2011/06/16/weird-wild-spongebob-
mushroom-named/
Blood
https://www.msu.edu/~kalinkat/professionalpages/TechMatrixMaterials/documentarybloodmisconceptions.htm
Hodgson: incorrect
Michigan State Uni: correct
Anatomy - External
GETTING OXYGEN FROM WATER: FISH GILLS• Each gill made
of four bony gill arches.
• Gill arches lined with hundreds of gill filaments that are very thin and flat.
GETTING OXYGEN FROM WATER: FISH GILLS
• Gill filaments are have folds called lamellae that contain a network of capillaries.
• Blood flows through the blood capillaries in the opposite direction to the flow of water.
Each gill arch has many filaments
Each filament has many lamellae
RADAR TIME
• Using your Radar, colour in how developed your knowledge is of the anatomy of the fish gill.
• If you colour:– 1/3: Trace and label the structure from TB
p212 on a new piece of paper– 2/3 : Do p193 in WB– 3/3: put your hand up
OSMOSIS INTERNAL You have 10 min.
? = more info required
X = incorrect
* = does not make sense
CV = control variable identified
General comment:
Make sure you identify the correct Independent, Dependent and Control variables before moving on
ANIMAL Diversity 6Learning Intention:
Describe how a moist, thin, large surface area within a gas exchange system is achieved in fish
SUCCESS CRITERIA:
Explain gas exchange in fish
DO NOW:
Draw a mammals respiratory
Structures (include lungs AND
close up of alveoli). Use red and blue
to show Blood oxygenation
GETTING OXYGEN FROM WATER: FISH GILLS• Gills covered by an
operculum (flap)• Fish ventilates gills by
alternately opening and closing mouth and operculum water flows into mouth over the gills out under the operculum
• Water difficult to ventilate gills near surface of body
WATER AS A GAS EXCHANGE MEDIUM
No problem in keeping the cell membranes of the gas exchange surface moist
BUT
O2 concentrations in water are low, especially in warmer and/or saltier water
SOthe gas exchange system must be very
efficient to get enough oxygen for respiration
Concentration
gradient problem!
ENHANCING THE EFFICIENCY OF FISH GILLS
• 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
• Gills are moist: fish live in water!
ENHANCING THE EFFICIENCY OF FISH GILLS
Fresh water flows over gills in one direction.
COUNTER-CURRENT FLOW: water and blood in the gills flow in opposite directions
maintains a favourable concentration gradient for diffusion of both gases
Concurrent flow animation
Countercurrent flow animation
CONCURRENT FLOW
COUNTER-CURRENT FLOW
Blood gets max
Blood gets max
50% saturation in
50% saturation in
oxygen!oxygen!
Task
Radar•1/3 – come sit in front bench
•2/3- continue with TB p194 as a group, utilizing answer booklet
•3/3 – worksheet
ANIMAL Diversity 7 and 8Learning Intention:
Compare and contrast how efficient gas exchange is maintained in 3 animal groups
SUCCESS CRITERIA:
Explain how efficient gas exchange is maintained in 3 animal groups
DO NOW:
Draw a fish’s respiratory
Structures.
Use red and blue
to show Blood oxygenation
Insects Mammals FishExplain how the concentration gradient is maintained
Explain how the diffusion distance is minimised
Explain how the gas exchange surface is kept moist
Explain how a large gas exchange surface area is provided
Remember – annotated diagrams tell 1000 words!You have the double period to complete this to Excellence standard.
Use your notes, books, and the PWP is available to use
GETTING OXYGEN FROM AIR: MAMMALS, BIRDS & INSECTS
As a gas exchange medium, air has many advantages over water:
• Air has a much higher oxygen concentration than water
• Diffusion occurs more quickly so less ventilation of the surface is needed
• Less energy is needed to move air through the respiratory system than water
BUT
as the gas exchange surface must be moist, in terrestrial animals water is continuously lost from the gas exchange surface by evaporation
SO
the gas exchange surface is folded into the body to reduce water loss.
GETTING OXYGEN FROM AIR: MAMMALS, BIRDS & INSECTS
WARM-BLOODED ANIMALSWarmth speeds up body’s reactions
enables faster movement etc
BUT
increases evaporation of water from lungs
AND
increases demand for energy to stay warm
SO
higher demand for gas exchange to provide O2 for and remove CO2 from respiration
ANIMAL Diversity 9
Essay scaffolding
ANIMAL Diversity 10Learning Intention:
Compare and contrast colours of gas exchange surfaces
SUCCESS CRITERIA:
Explain similarities and differences in colours of gas exchange surfaces
DO NOW: •Draw fish, mammal and insect
respiratory structures. •Label and use red/blue to
show oxygentaed and deoxygenated blood
Compare and contrast
• Colour. Why?
Unit Standard 8925• Wed
– P6 – Lung Dissection (40min) (element 1)
• Thursday– P3 – Gill dissection (element 1)– P4 – Write-up Element 1 and Element 2
Element 1 – Dissections
- Task 1 - drawing and labeling structures
- Task 2 - Write-up: 3 questions based on the structures.
Element 2 – Unit Standard test
- Task 1: how animal group achieves efficient gas exchange
- Task 2: How gas exchange systems are related to the animals way of life
How many filaments?
• You will have to work out how many filaments a fish has in your Unit Standard
How will you do it?
Step 1: count the number of filaments in a cm piece of gill arch
Step 2: ….