DNA Instruction Molecule 5-8 yrs

Updated Mar 18, 2023

Goal: Introduction to genetics and the basis of the building blocks of life.

Materials Required:

Activities:
DNA Extraction

Kiwi fruits (one per person)
Plate and fork (do not mash the kiwi in a mixer blender or you'll break the DNA)
5g (2 tsp) of liquid dish soap
2g (1/2 tsp) of table salt
100mL (1/2 cup) tap water
100mL (1/2 cup) of ice cold rubbing alcohol (put in freezer for at least 30 min)
Coffee filter paper
One clean, transparent glass
Ziplock bag

Build a DNA molecule Using Candies

2 pieces of regular Twizzlers candy
1 bag of medium Gummy Bears (4 Gummy Bears of each 4 colours)
8 toothpicks

Preparation:

Time: 20-30 minutes for peeling and cutting the kiwi, and gathering supplies.
Activity - DNA Extraction: Pre-peel the kiwi and pre-cut it in small pieces so the group just has to make a puree out of the pieces.

Opening

Enjoy your usual opening and have everyone sit down and ask the group about what they know about science, and what we are made of. Inform them they are going to make their first scientific experiment and discover the recipe molecule for life.

DNA Basic Information

The DNA is the instruction for making you. It is the genetic information, a biological text/instructions/molecule that encodes for every organism’s components, structure, and purpose (they are the building blocks). It contains the information for growing your feet down to your legs, your fingers on your hands not on your head, your nose in the middle of your face. Our DNA decides what we look like and how we grow. The genetic information is what makes you physically similar to the other people around you, but also makes you different (hair, skin or eyes color, height, male or female). Each person has their own version of the “human instruction manual” and only identical twins share the exact same genetic information.

You inherit your DNA from both your parents, who inherited theirs from their parents, and so on.

The DNA is a record of instructions telling the cell what its job is going to be. It is written in a molecular alphabet of 4 “letters/molecules”: A, T, C and G. A and T only pair together, while C and G only pair together.

DNA molecules have a coiled braid or ladder shape. Not visible to the naked eye. They are very long and very thin molecules, which are wrapped on themselves as compact forms called chromosomes.

Activities

DNA Extraction

Time: Approximately 45 minutes

INSTRUCTIONS:

Peel the kiwi and chop it into small chunks (remove the brown skin. It is dead and doesn’t have much DNA).
Put the chunks in a plate and mash the kiwi as much as you can; this helps break the cells apart. Put the mashed kiwi into a Ziplock bag.
Mix together the dish soap, salt, and water very slowly until the salt is fully dissolved. Try not to make bubbles! This mixture is your extraction buffer. The soap breaks up the cells, while the salt helps the DNA dissolve in water.
Add the extraction buffer to the mashed up kiwi and close the bag, leaving no air inside. Slowly and thoroughly mix by gently pressing back and forth on the bag.
Let the mixture stand (incubate) for 20 minutes at room temperature.
Filter the kiwi and buffer mixture through the coffee filter into a clean, transparent glass. You should be left with a green liquid that contains the kiwi DNA.
Pour the cold alcohol gently on the inside wall of the glass. The alcohol will form a transparent layer on top of the kiwi mixture. Because the DNA cannot dissolve in alcohol, at the interface between the kiwi mixture and the alcohol you will see a white jelly-like precipitate. Do not mix; this is the DNA. You can hook the DNA out using a fork or a stick.

The DNA you’ve extracted comes from billions of kiwi cells, which is why you can see it. However, DNA is so thin that if you unravel it you won’t be able to see a single DNA strand without an incredibly powerful microscope.

Build a DNA Molecule Using Candies

Time: 15-20 minutes

This is the DNA molecule that is condesned in the jelly blob that you just extracted from the kiwi.

INSTRUCTIONS:

Take out four red, four clear, four yellow and four green Gummy Bears.
Carefully thread a green and clear Gummy Bear onto a toothpick (be careful not to poke your fingers while doing it). The Gummy Bears should touch each other and meet in the middle of the toothpick leaving extra space on either side of the toothpick.
Reproduce step #2 pairing the 3 other green and clear Gummy Bears.
Thread the red with the yellow Gummy Bears the same way that you did with the green and clear. You should have 8 pairs of Gummy Bears onto toothpicks.
Randomly put each toothpick in the middle of the two strands of Twizzlers.
Twist it a little and you have your double DNA strand. Your body contains one billion times more of what you have here (in terms of number of pairs).

Closing

Enjoy your regular closing and ask the group to remember what you talked about science, life, and genetics. Have them bring home their craft (candy DNA molecule) to show their parents.