Biology 2.6: Describe diversity in the structure and function of animals

1. Biology 2.6: Describe diversity in the structure and function of animals Chapter 21 in Textbook (p210) Achievement Standard 90462 3 Credits

2. 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

3. What is Diversity? http://www.youtube.com/watch?v=jLuK-EBkcww • 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.

4. 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

5. Terminology • 73774728466 • 427 39242643 • 273284464

6. Gas Exchange • “The movement of gases across a membrane” Why do we need to carry out gas exchange?

7. Figure 10.8A

8. Breathing Animation Photo

9. 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

10. We will be studying the diversity of adaptations for this process in THREE animal groups: GAS EXCHANGE IN ANIMALS Fish Insects Mammals

11. GAS EXCHANGE SURFACES Gases 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 moistsurface • O2 and CO2 must be dissolved in water to diffuse across a membrane

12. GAS EXCHANGE SURFACES To maximise diffusion, an efficient gas exchange surface will… • have a large surface area • provide a small distance for gases to diffuse across • be moist • Maintain a favourable concentration gradient for the diffusion of both gases.

13. STRUCTURE OF THE GAS EXCHANGE SURFACE Depends on: • the size of the organism • where it lives – water or land • the metabolic demands of the organism – high, moderate or low DIVERSITY IS REQUIRED!!!!

14. 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

15. 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

16. multicellular animals need a gas exchange system • 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. • 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.

17. Task • Do WB p 191, 192 • 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

18. 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

19. Gas Exchange in Insects • Take your photocopy, and make notes as we move through the process of gas exchange for insects

20. 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.

21. 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

22. 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.

23. 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

24. Spiracle Trachea

25. Task • WB page 196

26. ANIMAL Diversity 4 Learning 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

27. Human Respiratory System Figure 10.1

28. Four Respiration Processes • 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

29. Components of the Lower Respiratory Tract Figure 10.3

30. MAMMAL LUNGS: BREATHING Two lungs ventilated by movement of diaphragm and ribs

31. MAMMAL LUNGS: STRUCTURE Rubber cast of human lungs

32. MAMMAL LUNGS: STRUCTURE • System of tubes (held open by rings of cartilage) allow air to flow in and out of lungs • Air enters via trachea (windpipe) • Trachea branches into two bronchi (one bronchus to each lung) • Bronchi branch into bronchioles

33. MAMMAL LUNGS: STRUCTURE Many 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

34. GAS EXCHANGE IN MAMMALS Gas exchange animation

35. ENHANCING THE EFFICIENCY OF MAMMAL LUNGS 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 • 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

36. Task • WB p 197-199 • http://bcs.whfreeman.com/thelifewire/content/chp48/4802002.html

37. ANIMAL Diversity 5 Learning 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/

38. Blood https://www.msu.edu/~kalinkat/professionalpages/TechMatrixMaterials/documentarybloodmisconceptions.htm Hodgson: incorrect Michigan State Uni: correct

39. Anatomy - External

40. 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.

42. 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.

44. Each gill arch has many filaments Each filament has many lamellae

45. 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

46. 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

47. ANIMAL Diversity 6 Learning 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

48. GETTING OXYGEN FROM WATER: FISH GILLS • Gills covered byan 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

49. WATER AS A GAS EXCHANGE MEDIUM No problem in keeping the cell membranes of the gas exchange surface moist BUT Concentration gradient problem! O2 concentrations in water are low, especially in warmer and/or saltier water SO the gas exchange system must be very efficient to get enough oxygen for respiration

50. 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!