Download Directions for Dog Breed Genetics

Name:_________________________________Block: ____
Date: _______________
Directions for Dog Breed Genetics
The purpose of this activity is to have fun while learning one of biology’s central dogmas:
how DNA is transcribed into mRNA which is then translated into an amino acid sequence that makes
up a specific protein.
The domesticated dog (Canis familiaris) is an interesting species to study because it is possibly the
most diverse mammal species on Earth. There are more than 300 dog breeds that exist,170 of which
are recognized by the American Kennel Club. The different breeds were developed through human
breeding, which followed the domestication of the gray wolf. Breeding has caused the huge range in
size, shape and behavior of dogs. This allows scientists to compare genes between breeds and connect
them to the traits that result from the genes. The dog’s genome was first sequenced in 2005.
Directions:
You will receive the DNA of an unknown breed of dog. Your job is to figure out the dog’s breed
by doing the following:
 Transcribe the DNA into mRNA.
 Use the mRNA codon chart below to determine the amino acids the DNA codes for.
 Refer to the Dog Trait Key to determine which amino acid sequences code for each trait.
 Based on the traits of your dog, determine which breed’s DNA you have!
After you finish, please answer the analysis questions.
mRNA Codon Chart
Name:_________________________________Block: ____
Date: _______________
Dog Genetics Analysis Questions
1. What breed of dog do you have?________________________________
2. In your own words, explain the process of transcription. Be sure to include where it takes place,
which cellular structures are involved, and which biomolecules are involved.
3. In your own words, explain the process of translation. Be sure to include where it takes place,
which cellular structures are involved, and which biomolecules are involved.
4. In your own words, explain how an organism’s DNA relates to its traits.
5. Suppose you knew the amino acid sequence of a specific protein in a cell.
a. How could you determine the sequence of DNA that coded for them?
b. Using your answer to part a) identify the DNA sequence that codes for the polypeptide:
Met-Try-Arg-Gly.
Name:_________________________________Block: ____
Date: _______________
6. Explain how one change in a DNA nucleotide could alter the formation of a protein. (An example
is the difference between normal and sickle-cell hemoglobin.)
7. From a genetics standpoint,
a. What is a mutation?
b. What type of mutation might not affect the resulting protein?
c. What type of gene mutation is most harmful? Why?
8. Below is a DNA strand that codes for coat color and a second strand which codes for a different
coat color. What type of mutation has occurred? How does this affect the amino acid sequence
produced? (Hint – transcribe and translate the strands!!)
DNA strand #1: TACAAAGAACAATACATT
DNA strand #2: TACAAAAAACAATACATT
9. Below is a DNA strand that codes for coat color and a second strand which codes for a different
coat color. What type of mutation has occurred? How does this affect the amino acid sequence
produced? (Hint – transcribe and translate the strands!!)
DNA strand #1: TACAAAGAACAATACATT
DNA strand #2: TACAAGAGAACAATACATT
Name:_________________________________Block: ____
Date: _______________
DOG TRAITS KEY
Phenotype
Amino Acid Chain
Coat Color
Brown
Met-Phe-Leu-Val-Met
Black
Met-Phe-Phe-Val-Met
Red-Brown
Met-Phe-Ser-Val-Met
Yellow
Met-Phe-Thr-Val-Met
White
Met-Thr-Val-Met
Fur Type
Curly, Short
Met-Lys-Tyr-Arg-Thr
Straight, Short
Met-Lys-Phe-Arg-Thr
Straight Long
Met-Lys-Arg-Phe-Thr
Wavy Long
Met-Lys-Tyr-Thr-Arg
Body Shape
Small, thin, long, straight
Met-Pro-Leu-Gly-Gln
Large, thin, long tapered
Met-Pro-Leu-Ala-Gln
Medium, very muscular, short
Met-Pro-Leu-His-Gln
Large, semimuscular, Straight
Met-Pro-Ile-Ala-Gln
Head Shape
Long, Thin
Met-Phe-Asp-Glu-Arg-Leu-His-Pro
Flat
Met-Leu-Asp-Glu-Arg-Leu-His-Pro
Short
Met-Leu-Asp-Glu-Arg-Phe-His-Pro
Name:_________________________________Block: ____
Date: _______________
Legs
Long, thin
Met-Gly-Arg-Gln-Asp
Short, Stubby
Met-Arg-Gln-Asp
medium long
Met-Gly-His-Gln-Asp
Stocky, muscular
Met-Gly-Trp-Gln-Asp
Tail
Long with Short Fur
Met-Pro-Thr-Asn-Glu-Ala
Long with Bushy Fur
Met-Pro-Ser-Asn-Glu-Ala
Pompom Tip
Met-Pro-Thr-Thr-Asn-Glu-Ala
Short Nub
Met-Pro-Asn-Glu-Ala
Ears
Small Pointy
Met-Val-Gly-His-Gln
Big Droopy
Met-Val-Gly-Trp-His-Gln
Medium Square
Met-Val-Gly-His-Trp-Ser-Gln
Medium Droopy
Met-Val-Gly-Gln
Eye Color
Dark Brown
Met-Asn-Asn-Val-Arg
Light Brown
Met-Ser-Asn-Val-Arg
Blue
Met-Ser-Val-Arg