BE PREPARED

Materials

Class materials:

• 2 rubber bands, 7” ! 1/8” 2 fixed pulleys 
• 4 flexible straws 
• 20 metric rulers 
• 4 balloons, same color 10 400 ml beakers 
• 3 liter pitchers 
• 1 glass stir rod 
• 3 L water 
• Red food coloring Masking tape 
• Scissors  
• 1 marker 

Group materials 

(groups of three or one group per lab table)

• 2 100 ml beakers 
• 1 plastic dropper 
• 1 100 ml graduated cylinder

Individual materials

• Student Data Record

TEACHER PREPARATION

The Performance Assessment uses stations. 

1. Pulley Model Station

A. Cut two rubber bands in one place so that each rubber band is in one long piece.

B. Thread one end of a rubber band over a pulley and tie a knot in the free end of the rubber band. Tie the knot as close to the free end of the rubber band as possible.

 

C. Pull the rubber band over the bottom support of the pulley clamp.

C. Repeat steps 2 and 3 for the second pulley. 

D. Attach the pulleys to a lab table that is set-up as Station 1. Label the lab table with tape next to each pulley as “leg model A” and “leg model B.”

E. Make sure the knots of the rubber bands are NOT along the surface of the clamps that are attached to the table (below). Re-adjust the rubber bands if necessary.

 

F. Tape two flexible straws together. The straws will represent a model of the lower leg. Bend the straws to form the lower leg and foot. Tape the straws to the front of the pulley (see below). Repeat for the second pulley.

G. Label the pulleys as shown below.

H. “Leg A” is complete. It models the leg before the accident.

I. To complete “leg model B,” cut the rubber band as shown in Figure 6.7. “Leg model B” models the leg after the accident.

 

2. Prepare the reaction time test models:

A. Use a piece of masking tape to mark the 7 cm mark on ten rulers. Label “A.”

B. Use a piece of masking tape to mark the 20 cm mark on ten rulers. Label “B.”

3. Prepare the lung models station.

A. For “lung model B,” blow up two balloons of the same color. Be sure that each

balloon is approximately the same size. Use a piece of masking tape to attach the

two balloons together. Place balloons on a lab table that is set up as Station 2 and

label “lung model B” (a, below).

B. For “lung model A,” blow up one balloon that is approximately the same size as the

balloons in “lung model B.” Blow up the second balloon so that it is noticeably

smaller than the first balloon. Use a piece of masking tape to attach the two balloons

together. Place the balloons on the Station 2 lab table and label “lung model A”

(b, below).

4. Prepare the heart and blood model.

A. Fill three-liter pitchers each with 1 L of water. Add 12 drops of red food coloring to

each pitcher and stir until completely mixed.

B. Pour 300 ml into ten 400 ml beakers.

5. Organize the required materials at a distribution point.

6. Separate the class into cooperative groups of three.

INSTRUCTION

1. Direct students to use the materials available to them at the distribution point to participate in this performance assessment: one (1) metric ruler labeled “A”, one (1) metric ruler labeled “B,” two (2) empty 100 ml beakers, one (1) 100 ml graduated cylinder, one (1) 400 ml beaker containing 300 ml of red water, and one (1) plastic dropper.

 

PROCEDURE

1. Begin the Performance Assessment by either reading the opening paragraph from the Scientist Data Record aloud or encouraging students to read the paragraph independently. Briefly review the contents of the paragraph and outline the goals of this project to the class. Read aloud the goals from the list on the Scientist Data Record.

2. Before students begin the investigation, walk through the five steps in the project. Encourage students to be creative and draw on their understanding of the systems of the human body from the first five investigations.

3. Explain to students that goals 1 and 3 are set-up as stations. Student groups will rotate through these stations at the teacher’s direction. If students come to goal 1 or 3 before reaching the station, they should skip goal 1 or 3 and move on to the next goal of the Performance Assessment.

4. Allow students to complete their performance assessments. You may wish to informally or formally evaluate students as they work on their performance assessments.

5. Upon completion of the project, permit enough time to clean up the lab and return the materials and equipment to their assigned location.

CLEAN UP

Let students know your expectations and instruct them to clean up their lab bench after the Performance Assessment.