DOG DNA  You will be assigned a partner.  You will need:  1 envelope with 32 gene strips  Tape  Construction paper  Markers  Trait Map (Moodle)

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Background  In the nucleus of (almost) every cell there are chromosomes.  Chromosomes are bunches of DNA.  A piece of DNA is called a gene.

Like a ball of yarn… Chromosome DNA Gene

Background  DNA is a set of instructions that determines the traits of an organism.  Every organism inherits a unique combination of DNA in their cells.  These variations, or differences, in the DNA lead to the inheritance of different traits.

Background  So, DNA is like a “recipe” for traits in all organisms.  Genes are like the individual steps or ingredients in the recipe.  Differences in the DNA “alphabet” are what make differences in traits  If you use a different ingredient in the recipe, you will get a different product!

Dog DNA  In this activity, you will create the “recipe” for a dog by creating a long DNA strand with genes for various dog traits.  You will then use that recipe to create your own dog!

Building Blocks  These are the building blocks for our dogs. You will choose 1 strip of paper for each trait, like eye color. What does this strip represent?

Building Blocks  These are the building blocks for our dogs. You will choose 1 strip of paper for each trait, like eye color. A GENE!

Building Blocks  Each gene is made up of certain molecules – Adenine (A), Cytosine (C), Guanine (G), Thymine (T).  The 4 symbols represent these “bases”.

Building Blocks What does a whole bunch of genes together make?

Building Blocks DNA!

Create your dog  First, make the DNA strand while circling the traits on the instruction document.  Second, use the DNA strand and the trait list to draw your dog!

Finishing Touches  Name your dog and put your names on the back.  If your dog is a male, tape the long DNA strip to the left hand side of your dog’s picture.  If your dog is a female, tape the long DNA strip to the right side of your dog’s picture.

Discussion  The DNA molecule contains a sequence of four chemical bases (represented here by four symbols). Each base is referred to by the first letter of its name: Adenine (A), Cytosine (C), Guanine (G) and Thymine (T).  The sequence of these chemical bases encodes a detailed set of instructions for building an organism’s traits. (The human genome contains approximately 3 billion pairs or bases!)  Each one of you assembled the DNA strips in the order they were drawn. This is because all individuals of a species have the same genes in the same order along their chromosomes. (This is what allows researchers to “map” the location of a gene to a specific place on a chromosome.)

Discussion  It is the small sequence variations within each gene that lead to differences in traits. There is usually a limited number of sequence variations for a gene. That is, a gene usually comes in a few different forms or flavors, called “alleles”.  There was a possibility of four different alleles for each of the dog genes in this activity.  In this activity, a single gene determined each dog trait. More often a trait is influenced by more than one gene as well as environmental factors.