Part of Lesson Plan: DNA & You

Activity Overview / Details

Building DNA Samples

This activity works best as a cooperative group learning activity. Prior to assigning this activity, have students read about DNA and/or discuss the information in class. Students should be familiar with nucleotides, the building blocks of DNA. A nucleotide is made up of three molecules; a sugar, a phosphate group, and a nitrogen base. A diagram of the DNA model would help students as they work to build the model.

Key Terms:

DNA, deoxyribonucleic acid, model, modeling, DNA modeling, genetics, genome, candy model, heredity, genes, nucleotide, hereditary information

Teacher notes:

Recall that DNA is a polymer of 4 different nucleotides. A nucleotide consists of a sugar (deoxyribose), a phosphate group, and a nitrogenous base. There are 4 of these bases that make up the 4 different nucleotides: Adenine, Thymine, Cytosine, & Guanine.  In a double strand of DNA, the A nucleotide always matches up with a T, while C always matches up with G. These pairs (A-T, C-G) are called complimentary base pairs. In this lab we will construct a segment of DNA and then unzip and replicate it.

Part I: Building a DNA Model

1. Use a diagram of DNA and the key below to build four different nucleotides

• Orange slice = deoxyribose sugar Purple gum drop = Thymine nitrogen base
• White gum drop = phosphate group Yellow gum drop = Cytosine nitrogen base
• Red gum drop = Adenine nitrogen ba   Green gum
• Green gum drop = Guanine nitrogen base
• Plain toothpicks = chemical bonds

Alternate nucleotides Supplies:

• Gummy Bears
• Twisters (red, black & multiple colors
• small marshmallows (various colors)

Closing Activity:

Students are prompted to discuss DNA and describe their model. Students will explain how their models differ from real DNA. Students should describe how each component of their model and how it relates to the real thing. Teacher will explain the overall outcomes of the activity.