Building a Model of an Air Sac
For your museum display, you will build several threedimensional models. Here is just one idea for making a model.
- large white balloon
- thin plastic tubing
- red, purple, and blue buttons
- clear plastic tape
- sheets of red and blue construction paper
- Blow up a balloon. Tightly tie the base of the balloon so that the air does not escape. This balloon represents an air sac in the lungs.
- Wrap plastic tubing once around the balloon. Cut the tubing.
- Divide the tubing into thirds. Place a pencil mark at the first third and a pencil mark at the second third.
- Glue blue buttons end to end along the first third of the tubing. Then glue
purple buttons end to end along the second third of the tubing. Last, glue
red buttons end to end along the last third of the tubing. See the drawing.
- Tape the plastic tube to the balloon, as shown.
- From construction paper, cut out red and blue arrows. Tape these arrows to the balloon to show the exchange of oxygen and carbon dioxide inside the air sac.
- Make and attach these labels to the model: red blood cell, air sac, carrying
carbon dioxide, carrying oxygen.
- On a sheet of paper write a title and description of what the model shows.
- With other students, brainstorm ways to improve the model.
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