Wear a Bear

What makes us different from other living things?

We are all made up of the same “stuff” – but put together in a different way! DNA is what we call the specific instructions that make up our body. It’s teeny tiny in your cells and is shaped like a long, twisted ladder, made of different building blocks. All of these things work together to make you YOU!

*This activity is adapted from “Wear a Chimp on Your Wrist” by the American Museum of Natural History’s Ology, found at https://www.amnh.org/explore/ology/genetics/wear-a-chimp-on-your-wrist2

Objective:
Identify the bases that make up a sequence of DNA
Understand and explain how different DNA codes make up different living things
Key Vocabulary
DNA, sequence

Facilitator Background:

• DNA or “deoxyribonucleic acid” is a long molecule that contains our unique genetic code. Like a recipe book it holds the instructions for making all the proteins in our bodies 
• DNA contains four basic building blocks or ‘bases’: adenine (A), cytosine (C), guanine (G) and thymine (T)
• The order, or sequence, of these bases form the instructions in the genome
• DNA is a two-stranded molecule and each strand is composed of long sequences of the four bases, A, C, G and T.
• DNA has a unique ‘double helix’ shape, like a twisted ladder
• The bases on one strand of the DNA molecule pair together with complementary bases on the opposite strand of DNA to form the ‘rungs’ of the DNA ‘ladder’
• The bases always pair together in the same way, A with T, C with G.
• Each base pair is joined together by hydrogen bonds
• This double helix structure was first discovered by Francis Crick and James Watson with the help of Rosalind Franklin and Maurice Wilkins.
• The human genome is made of 3.2 billion bases of DNA but other organisms have different genome sizes

This information and more from yourgenome.org

 Kid Friendly Language:

• DNA is the name for the “instructions” that are inside all of the tiny cells in your body
• Everyone has a different DNA code that makes us who we are. Animals also have different DNA codes that make them unique!
• DNA is made up of bases, and each base has a buddy – A always goes with T, C always goes with G
• If the order of the bases changes, the “instructions” will be different
• DNA is special to everyone – that’s why you might see a police officer looking for hair, saliva , or skin to find at a crime scene
• The spiral shape is called a double helix

Materials:

• Beads in four different colors (we used green, blue, yellow and orange)
• Two pieces of string about 12 inches
• Scissors
• DNA Codes (Attached or printable from website)

Activity Plan

1. Connect to prior knowledge:
   • Ask: Have you ever followed a recipe before? What do you think might happen if we didn’t follow the recipe, changed the order, and added too many eggs, or less flour?
   • Explain: The cake would change! There are also instructions in our cells that make up our bodies! It’s called DNA. DNA is kind of like a recipe that’s made of four different bases that work together to make our bodies what they are. Animals also have DNA!
   • Explain: Researchers and scientist have figured out how to look at different animals’ DNA recipes/codes. Today we’ll look at tiny sections of different recipes from different animals
   • Explain: The bases always have buddies (A with T and C with G), and we’ll use that to help us represent animal DNA code in bracelets.
2. Separate your beads into four colors, each representing one letter of DNA: A, C, G, T. We made ours the following:

3. Cut two strings about 12 inches in length and tie at least one knot about two inches from one end of each string. Make sure the knots are big enough so the beads won’t slide off!

4. Your bracelet will have two strands to represent the two strands in DNA, and each side will match. A always matches with T and C always goes with G. So when you string an A onto one strand, a T must go onto the other.

5. Begin stringing beads onto the string in the order of the DNA code. Below is the pattern for a brown bear!

6. Tie a knot around the last bead of each string. Then tie the ends of the strings together to complete your bracelet

Follow- Up Questions

What happens if you change the order of the pairings? What would be the result? Would it still be a grizzly bear?

Extension Activities

• “Hooray for DNA”- Humans have a lot in common – but also a lot of differences, starting with our DNA. Make your own double helix using tooth picks and gummy bears or magic craft noodles (use water for noodles to stick together) 

Check it Out!

Videos:

More DNA Sequences