Dog DNA

Can you describe the relationship

between: DNA, Chromosomes, Genes, and Traits?

DOG DNA You will be assigned a partner.

You will need: 1 envelope with 32 gene strips Tape Construction paper Markers Trait Map (Moodle)

Song

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.