Skeletal System Lesson Plan
From National Space Biomedical Research Institute (NSBRI)
Can be found online at <http://www.bioedonline.org/resources/nsbri.cfm>
SC Science Standard 7-3: The student will demonstrate and understanding of the functions and
interconnections of the major human body systems, including the breakdown in structure or function that
disease causes (Life Science).
Materials needed per group:
-
2 paper bathroom cups
1 sheet of cardboard (optional: use if weights are not flat)
Pinto beans (any dried bean will do)
Scale (preferably a heavy weight scale)
Calculators
Some kind of stackable weight (students can use workbooks, notebooks or other classroom
materials)
Activity
1.
2.
3.
4.
Fill one of the cups with the beans but leave the other one empty.
Weigh the empty paper cup on the scale and record it in the data table
Place a sheet of cardboard on top of empty paper cup (placed right side up)
Stack as many of the “weights” on the cardboard that you can until the paper cup gives way and
crumples.
5. Determine the total weight of all the weights (either weigh them together or weigh them
separately and add together) and record that in the data table.
6. Divide the total weight supported by the paper cup by the weight of the empty paper cup and
record that in the data table.
(Total weight supported by paper cup/weight of empty paper cup)
7. Repeat the experiment using the cup filled with beans
Hollow
Solid
Weight of Cup
Weight of objects supported by cup
Weight supported/weight of cup
(Ratio)
Questions
1. Which cup (hollow or solid) could hold the most weight?
2. Which cup (hollow or solid) had the highest ratio of weight supported to cup weight? What do
you think this means and why do you think we calculated the ratio?
3. Using the information gained in this lab activity, which type of bones (hollow or solid) do you
think make up the human skeletal system?
4. Do you think bird bones would have a higher or lower “weight supported” to “weight of bone”
ratio? Why?
(After the students are done recording their data and answering questions as best as they can, have a
class discussion about what the students found. Students should find that the hollow cup had a higher
ratio than the solid cup. Use this finding to explain why it is important to consider both the weight of
the bone and how much it can hold. Yes, a solid, dense bone can hold a lot more weight than a
totally hollow one, but it would also be a lot harder for the organism to move regularly.)