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Notes for teachers

This is a one period lesson but does take some prep.
This lesson has some flexibility in regard to the type of candy that can be used. Keep in mind the toothpick needs to pierce the items.

List of Materials

• Masking tape or colored tape

• Two strands of long candy ropes (Twizzlers)

• Colored gummy bears (9 of each - green, pink, yellow, and orange) or colored marshmallows

• 12 dinner toothpicks

• 5 binder clips

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AZ Standards

Life Science

8.L3U1.9 Construct an explanation of how genetic variations occur in offspring through the inheritance of traits or through mutations

8.L3U3.10 Communicate how advancements in technology have furthered the field of genetic research and use evidence to support an argument about the positive and negative effects of genetic research on human lives.

Science & Engineering Practices

Developing and Using Models

A practice of both science and engineering is to use and construct models as helpful tools for representing ideas and explanations.

Use and/or develop models to predict, describe, support explanations, and/or collect data to test ideas about phenomena in natural or designed systems, including those representing inputs and outputs, and those at unobservable scales.

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Objective(s):

Learners will describe the correct base pairs. A - T and C – G
Learners will articulate the basic structure of a DNA molecule.
Learners will describe the function and rules of base pairing.
Learners will comprehend how information is encoded within the DNA molecule as a sequence of chemical bases (A, T, C, G).

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Agenda

Introduction (10 min)

Handing out materials (5-10 min)

Building the double helix (25 min)

Clean up/eat (10 min)

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Intro/Driving Question/Opening

Good morning, young geneticists! Remember when we talked about the fascinating world of DNA, our genetic blueprint? Well, today we're taking it up a notch. You're going to become confectionery constructors, building the very blueprint of life... out of candy!
By now, you know that our DNA, this incredible code inside every one of our cells, is what makes us who we are. It dictates everything, from your hair color to your height, and even your ability to roll your tongue. Isn't it astounding that all these traits come from different arrangements of just four bases, A, T, C, and G?
But, there's so much more to these four letters! They pair up in a specific way to form the steps of the DNA ladder, creating a magnificent twisted structure known as a double helix. And guess what? These pairs are not just for making pretty patterns - their exact pairing allows DNA to copy itself with remarkable accuracy!
So, how does all of this work? How can these four simple components construct such intricate and varied lifeforms? That's exactly what we're going to explore today.
We're going to build our very own edible DNA models using colorful and yummy candies. As we construct, we'll dive deeper into DNA's structure, delve into the crucial role of base pairs, and decode the mystery of DNA replication.
So, are you ready to up your DNA game, reveal the secrets of life's building blocks, and enjoy some sweet learning? Let's get started!

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Hands-on Activity Instructions

Use a diagram to explain the structure of the DNA molecule, including the base pairing rules. Highlight how the information is stored in the DNA molecule in the sequence of the chemical bases represented by A, T, C, and G. This will not be the first time they have been exposed to this information. This is also a good time to do a call and response to the class and do a quick audible quiz to see if they can match the letter you call out and reward them with some of the leftover candy.

Invite learners to construct their own edible model of DNA using the provided materials in pairs. Hand out the materials.

If there is an odd person out invite them to work with you, go solo or be a team of three.

Upon completion of the models, evaluate learners' understanding of the DNA structure by checking if they've built and labeled their models accurately, and if they've followed the base pairing rules.
Summarize by restating how the structure of DNA and its base pairing rules allow it to store inheritable information effectively.

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Project or Print

DNA provides the blueprint for all living organisms. It is broken down into sections, known as genes, each coding for a protein that carries out specific tasks in the cell.
A DNA molecule comprises two backbones and four types of chemical bases - adenine (A), thymine (T), cytosine (C), and guanine (G). The backbones are made up of alternating phosphates and sugars, while the bases pair in a fixed manner - A with T, and C with G.
A DNA molecule can be likened to a twisted ladder, with the backbones forming the sides, and the base pairs forming the rungs. This structure is known as a double helix. The precise matching of the base pairs allows for the creation of exact DNA copies during DNA replication, a process vital for cell division.
The students can use whatever as long as it matches with the correct base pair.
The colors will be assigned as followed: Red is A, T is Orange, Green is G, C is Blue.

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Assessment

The assessment is the creation of the double helix as well as a formative assessment as you walk around the room.

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Differentiation

Pull the group aside that is having difficulty and work with them matching the base pairs.

Provide sentence stems for students to use to explain their thinking and observations.

Create a word wall with key vocabulary and an image.

Remediation

Extension/Enrichment

Add the component of researching who discovered DNA with a paragraph summary.