This week you will construct a 3-D model of DNA out of household junk. Make sure that you include the sugar-phosphate backbone and the nitrogen bases.

These beautiful works of art and science will hang in the room indefinitely, so be proud of what you do and take the time necessary to construct a nice model.

On the day this is due, you will be required to stand up in front of class and explain your model.


Exemplary (100%)

  • Everything in SUPERIOR plus:
  • model is in the double helix shape

Superior (90%)

  • Everything in EXCEEDS plus:
  • Hydrogen bonds, the correct number, between the bases are shown

Exceeds (85%)

  • Everything in MEETS plus:
  • A key to denote the bases, phosphates, and sugars is attached to the model

Meets (80%)

  • Sugar/Phosphate backbone is assembled properly
  • Bases are attached to each other and to the backbone in the correct location
  • Student can explain the difference between a purine and a pyrimidine

Approaches (75%)

  • One of the following is wrong:
  • Bases are attached to each other incorrectly
  • Backbone is not correct
  • Bases are not attached to the backbone correctly
  • There is either an incorrect explanation or no explanation of purines and pyrimidines

Needs improvement (50%)

More than one of the above is missing

Suggested Materials: dry macaroni, string, pipe cleaners, wire coat hangers, beads, white glue, cardboard, styrofoam peanuts, toothpicks.

Materials to avoid: anything that will mold, mildew, rot, melt, etc. such as marshmallows or gumdrops.

Click here for more details on the structure

If you can find it, be sure to show your students "The Race for the Double Helix" starring Jeff Goldblum.


Just for fun: If you have access to a 3-D printer, print a DNA model.