Things You'll Need
100 Styrofoam balls
75 double ended toothpicks
Wooden laboratory stand
Red, white, blue, green, yellow and orange paint
A 3-D model of a strand of DNA is an appropriate project for an elementary science fair that will even appeal to students more interested in the arts than in science. While this may seem like a difficult project to do, building a 3-D model is actually quite easy. With a few easy to obtain supplies and by following a simple set of instructions, anyone can make this model.
Lay down newspaper to protect your work surface and pour paint into plastic cups. Paint the balls using the six different colors and six brushes. You will need 24 red balls, 24 white balls, 13 blue balls, 13 green balls, 13 yellow balls and 13 orange balls. Let the balls dry.
Attach two toothpicks on opposite sides at the bottom of the stand, next to the base. Place a green ball and a yellow ball on the toothpicks.
Attach toothpicks into the green and yellow balls in the same direction as the original toothpicks.
Attach the blue ball to the toothpick coming from the yellow ball and an orange ball to the toothpick coming from the green ball.
Attach toothpicks to the balls on the end of this line. Place red balls on these toothpicks.
Place toothpicks in the red balls at a 45-degree angle. Place white balls in these toothpicks.
Place two more tooth picks in the white balls at the same angle as the prior toothpick. Attach two more red balls into these toothpicks.
Now put toothpicks toward the stand and attach the blue, orange, yellow, and green balls like you did in steps three and four. Make sure you keep the balls in the same pairs and connect them to the stand with the toothpicks
Continue to work your way up the stand, with each line of balls off set from the one below it by 45 degrees. You will begin to see a "twist" as the balls work their way up the stand.
If you want a bigger model, just get more toothpicks and balls. The process will be the same.
Make sure you keep the pairs together. DNA is made up of four amino acids which are found in the same pairs.