Chapter 6 Lesson 2 "Respiration and Circulation"

Materials:

• Compare and contrast worksheet
• Animal Respiratory and Circulatory System Review.

Objective:

• Students will explain gas exchange in simple and complex animals.
• Students will tell the difference between open and closed circulatory systems.
• Students will trace the flow of blood through a bird or mammal.

Alaska Content Standards:

• SCI A-10 Students will understand that living things are made up mostly of cells and that all life processes occur in Cells (Cells)
• SCI A-12 Students will distinguish the patterns of similarity and differences in the living world in order to understand the diversity of life and understand the theories that describe the importance of diversity for species and ecosystems.
• SCI A-13 Students will understand the theory of natural selection as an explanation for evidence of changes in life forms over time (Evolution and Natural Selection)
• SCI A-14 Students will understand the interdependence between living things and their environments; that living environments consists of individuals, populations, and communities; and that a small change in a portion of an environment may affect the entire environment (Interdependence);
• SCI A-15 Students will use science to understand and describe the local environment.
• SCI B-1 Students will use the processes of science: observing, classifying, measuring interpreting data, inferring, communicating, controlling variables, developing models and theories, hypothesizing, predicting, and experimenting;
• SCI- D-2 Students will understand that scientific innovations may affect our economy, safety, environment, health, and society and that these effects may be long or short term, positive or negative, and expected or unexpected;

Anticipatory Set: The instructor will show the students a magnified image of a mayfly as its gills move rapidly in the water. Students will then be posed the following questions. Why do the gills move? What does the mayfly get from the water? How are these structures like lungs?

Define Respire

Teacher Input: Students will be shown the diagram on P123. Students will be given a roadmap to the lesson. We will start out very simple and work our way up to more and more complex animals. Here are the key points about the gas exchange in simple animals.

• most very simple animals have body walls made of just two cells.
• both cells get rid of carbon dioxide and get oxygen through a process of diffusion with water. (Define diffusion)
• greater concentrations of oxygen in the water diffuse into the cell
• greater concentrations of carbon dioxide in the cell diffuse into the water.
• Examples, sponges, cnidarians(hydra), and flatworms.

More complex gas exchange needed because most animals are not just two cells thick: Use this picture and explain points about each type of gas exchange.

• Cell surface, see above, diffusion.
• Along the entire outer skin, circulatory system takes oxygen to each cell.
• Gills, more surface area for exchange and then circulatory system takes oxygen to each cell.(questions for students, Where do you find most animals that live in water? Why do gills have a feathery structure? "more surface area" What has to happen in the gills? "Oxygen has to diffuse into the blood and carbon dioxide has to diffuse out of the blood and into the water very quickly"
• trachea system allow airflow within the body. Air travels to the internal cells through small tubes. Insects abdomen pumps up and down to move air through the trachea.
• Lungs, a huge surface area is given for gas exchange in a countercurrent direction. Explain countercurrent exchange:

Teacher Modeling: What does the word circulatory mean? Break the word apart to figure out the definition. Show the students the two types of circulatory systems. What does the circulatory system do? How is it different in these two diagrams? How is it the same in these two diagrams? Compare and contrast the different circulatory systems using the first part of the Comparing Circulatory Systems sheet.

Define: Circulatory, Open circulatory system, annelid, Closed circulatory system.

Guided Practice:: Students will analyze the different types of circulatory systems in different vertebrates. Using this diagram and the second half of the worksheet.

Define: Atrium, and Ventricle

Closure: Have the students complete the compare and contrast worksheet.

Independent Practice: Students should complete the Animal Respiratory and Circulatory Systems review and then take the quiz on lesson 2.

Duration:

30 minutes + 10-15 for Independent Practice (Could be longer if taken for homework).