Class Activities
Note on Activities:
IB labs and activities have an emphasis on student inquiry and are in most cases meant to be student-designed. Therefore, many of the activities below do not have extensive directions or step-by-step procedures. They include enough information for more elaborate and structured instruction. Many of these activities include a form of multimedia assessment, which can be used in the culminating project of the unit. The content knowledge addressed in the standards listed in Appendix B will be assessed on a summative exam as well as on the senior IB exams in the spring. Activities are presented in chronological order of the unit and should be performed in conjunction with lectures rather than collectively at the end. Additionally, a pulse and blood pressure lab is recommended if school policies allow one.
Title: Displaying Circulation
Timeframe: Two class periods or one block
Necessary Background: This activity should serve as reinforcement after already covering the structure and basic functions of the heart and circulatory system.
Materials: red and blue yarn, scissors, butcher paper, markers, tape, iPad 2 or camcorder
Procedure: Have students work in groups of 3-4. One student should serve as a "stencil" and lay down on the butcher paper while another student draws an outline around the outside of their body. Students should then work together to draw the two lungs, a heart in the appropriate location and labels for the four chambers (left and right atria and ventricles) and the major arteries and veins (aorta, pulmonary artery, pulmonary vein, and vena cava). Instruct the students to cut the red yarn in the following pattern: 8 pieces long enough to go from the heart to the fingers, 8 pieces long enough to go from the heart to the toes, and 8 pieces long enough to go from the heart to the lungs. Students should cut the blue yarn in the same pattern. Next, students should lay the yarn strands out within the body structure so that the red yarn serves as the arterial network and the blue yarn as the venous system. Emphasize that the yarn represents blood volume rather than individual vessels. Remind them that one of the key ideas within the circulatory system is branching and maximizing surface area. Students should be able to work together to set up parallel arterial and venous systems that start as a cluster of 4 strands of yarn close to the heart, branching to two sets of two further along the limb or lung, and into individual strands in the hand, foot, or lung. When students are satisfied with their circulatory system, they should tape the yarn in place.
Modifications: Use markers or paint instead for a faster, more transportable project. Provide a demonstration or diagram for students that are struggling with the concept. To simplify the project, cover only the arterial or venous systems, or just the pulmonary or systemic circuits.
Assessment: Videotape the group explaining how and why they laid the yarn out in that particular pattern. Each student should have a speaking role and use specific terminology. Videos will be saved and available for students to use in their final portfolio project.
Title: Modeling Diffusion
Timeframe: One class period or half block
Necessary Background: This lesson should follow the lecture on gas exchange. My students learned diffusion and osmosis the previous year, so this activity is a quick review. Because osmosis is not an emphasized factor in the oxygen/carbon dioxide gas exchange, guide students in focusing on the movement of the iodine molecules rather than the water.
Materials: cornstarch, iodine, water, beakers, plastic baggies, camera
Procedure: Demonstrate the set-up to students and have them take notes to write their procedure (I have found this to be a useful technique when doing simple labs to review the importance of clear procedure-writing). Place a spoonful of cornstarch into a plastic bag, then add 100 mL of water, seal, and mix to dissolve into a solution. Fill a beaker with water and add 15 drops of iodine. Rinse off the exterior of the plastic baggie and place it in the iodine-water solution. Explain that iodine is an indicator for starch and that it will turn from golden/red to purple/black in its presence. Students should then review their procedures, make a hypothesis about if and where a color change may occur, and follow their own directions in pairs or groups of three. About 10-15 minutes after completing their set-up, students should see the interior of the baggie turn black as the iodine diffuses in and reacts with the starch.
Modifications: As mentioned with the other activities, more detailed directions can be offered to adjust the grade level for this activity. Advanced students can make the experiments more challenging by changing starch or iodine concentrations and measuring the rate at which the reaction (and diffusion) occurs.
Assessment: Students will prepare a simple lab report with their hypothesis, procedure, a diagram of their set-up and results (showing the movement of the iodine into the bag), and explanation of what happened. As a conclusion, they should relate their lab findings to gas exchange in the capillary beds. Students may take a picture of their results to include in their final portfolio.
Title: "A Day in the Life of Red Blood Cell"
Timeframe: Two class periods or one block
Necessary Background: Students should have mastery of the general structure and function of both the circulatory and respiratory systems.
Materials: iPads (1-2 students per device), internet access, "Comic Book" app (available from the iTunes app store for $1.99), LCD projector (this activity may also be done without any technology to create paper comic strips; "Comic Life" is a similar Macbook application if those are available instead of iPads)
Procedure: The idea behind this activity (whether performed with technology or not) is to have students show the path of an erythrocyte through the circulatory system. Students should incorporate the respiratory system by showing how the red blood cell picks up oxygen in the alveoli of the lung and deposits it at the capillary level of a tissue. Having students create comic books to show these events makes a difficult concept fun and tangible. Students should first brainstorm in groups about major events of the circuit of a red blood cell. Where does it go? What does it do? The students should be asked to summarize these events in 6-8 blocks of information using proper terminology (left atrium, capillaries, venules, etc.). Then students will be taught how to use "Comic Book" on the iPad on the LCD projector. The program is very simple and intuitive—save pictures to the iPad, select a format, drag and drop images, add captions, dialog bubbles, titles, and fun comic stickers. Students should use one panel for each major event that they wrote down in their summaries. Completed comics can be saved and emailed directly from the iPads.
Modifications: If time is limited, students may work in pairs and one can complete a comic for the pulmonary circuit and the other for the systemic circuit. The activity can be simplified by providing the significant events in a list for the students instead of having the initial brainstorm. If Comic Book is not an option, any graphic creation/editing program such as Microsoft Paint will suffice. Alternately, this entire activity can be completed entirely on paper. Students that are self-conscious or non-artistically inclined may bring in printed images or diagrams and add their own captions.
Assessment: Students creating multimedia projects will again include them in their final portfolio. Individual comic strips should be assessed on completion, complexity, and scientific accuracy, as well as for creativity.
Title: Circulation and Respiration Through Dissection
Timeframe: Two class periods or one block
Necessary Background: Students should have mastery of the general structure and function of both the circulatory and respiratory systems.
Materials: fetal pigs (dual injected, available through Ward's Scientific or Carolina Biological), dissecting kits and trays, gloves, lab aprons, goggles, iPad 2 or camcorder
Procedure: Students will be performing a standard dissection to examine the circulatory and respiratory systems within a living system, identify their primary components, and explain the structures as they relate to their functions. Pigs make an excellent dissection model because their systems are remarkably similar to humans. I recommend showing coloring plates from the Fetal Pig Coloring Book and a virtual dissection or tutorial (see Teacher Resources), especially if this is your students' first dissection. Students should work in groups of 3 or 4 and share responsibilities throughout the lab. Draw or use a diagram to show students the proper incisions to make. Instruct them to use scissors to gently cut a vertical line from the top of the chest to the bottom of the abdomen, then a horizontal line at both ends of the incision. Students will need to gently cut through skin, muscle, and the rib cage, but should be careful not to penetrate deeper, then pull and pin the skin and muscle layers off to the side to expose the internal organs. Using a text or dissection guide, students should work together to identify the heart, aorta, pulmonary artery, venae cavae, pulmonary vein, and lungs. Students may make shallow incisions to trace the femoral artery at the hip down through the smaller arteries and arterioles in the leg. The latex injections make it easy to see the path of the blood through the tissues. The heart and lungs may be removed for further study; students can dissect the heart to view the different chambers. When ready, students take turns narrating the structures and functions listed above and explain how the respiratory and circulatory systems work together.
Modifications: Frogs are a cheaper alternative to pigs, which still allow students to see some of the major components of the two systems. Virtual dissection is an option for students that are morally opposed to dissections or are squeamish.
Assessment: Students will need to create a diagram of the pig's internal anatomy at a later point in time and draw and label the tissues specifically mentioned above. Make a video recording of the students' narration and make it available for students to use in their unit project portfolios.
Ethical Debate Panel—Organ Transplantation and Artificial Organs
Timeframe: 2 class periods or 1 block
Necessary Background: Students should have an understanding of the major organ systems and their interactions and an overview on organ transplantation (need, statistics, general United States processes).
Materials: Technology with internet access (iPads or computers; alternately you can provide students with print resources; see Recommended Teacher Resources)
Procedure: Students should be given a day to research organ transplantation in the United States, focusing on the major question of how organ donation is regulated (both on the donating and receiving ends). Students should choose (or be assigned) a specialty to diversify the discussion. Some examples of specialization are:
-which organs can be donated
-how one becomes an organ donor in your state
-organ trade (point students toward Iran as an example)
-organ candidates and the waiting list
-unusual transplants (face, uterus)
Each student should prepare at least two questions on their specialty (at least one should be an ethics-based question) and be prepared to answer questions in their assigned area. On the second day, lead a discussion where students share their questions and respond to one another. The instructor should serve as moderator to keep the pace of the discussion on target, ensure scientific accuracy, call on "specialists" when related questions arise, and maintain respect for students' opinions.
Modifications: This activity could be made more personal by assigning students a series of questions to be answered in an essay format. If students are opinionated but not confident in speaking aloud on controversial topics, you could set up an online discussion board (see Appendix A— Technology Resources) instead.
Assessment: Students will be evaluated on the scientific accuracy of their output and critical analysis skills.
Unit Portfolio Project:
The unit will conclude with a project that will allow students to communicate their organ knowledge and apply research and media literacy. Each student will prepare an online portfolio using Glogster (see Appendix A— Technology Resources) to present their choice of three of the following:
-video of "Displaying Circulation" activity
-picture and annotation from "Modeling Diffusion" activity
-comic book diagram from "Day in the Life of Red Blood Cell" activity
-video from dissection activity
Students should also include the following two sections:
-a summary of current organ transplantation procedures and an opinion statement on these policies
-a summary of current health issues regarding either the heart or the lung and the ways in which they can be prevented
Announce this project at the beginning of the unit so that students are aware that they need to gather artifacts. Files shared between students can be uploaded and downloaded from Dropbox (see Appendix A— Technology Resources). Students may use the information presented in class as a foundation but will need to do further research (see Technology Resources for useful links) for the latter two sections. If the computer technology is not available for this project, students can gather artifacts and create paper-based portfolios instead. Evaluation will be based on scientific accuracy, creativity, and communication (presentation of materials in a way that the public can understand, as these are meant to be shared).
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