Name: ________________________________________
DNA, RNA, and Snorks
In this activity, you will examine the DNA sequence of a fictitious organism - the Snork. Snorks were discovered on
the planet Dee Enae in a distant solar system. Snorks have 7 pairs of chromosomes. Each pair of chromosomes has
the same type of gene on it. For example both chromosome ones contain a gene for body covering and both
chromosome twos contain a gene for body style. While the type of gene are the same on a pair of chromosomes, the
specific version of the gene (allele) may be the same or may be different. For example, one Snork may have a gene
that codes for a hairless trait on one of its chromosome ones and a gene that codes for a hairy trait on the other
chromosome one. Another snork may have genes that code for the hairless trait on both chromosome ones.
Your job is to analyze the two genes on each chromosome to determine what trait these genes code for. Then, using
the information and table below, predict which trait will show up in the Snork and draw the Snork.
IMPORTANT! Follow these important rules for gene expression:
1. If the Snork has two dominant or two recessive genes, that is the gene that is expressed.
2. If one of the genes is dominant and the other recessive, the dominant trait is expressed.
3. If the genes are incomplete dominance, a mix of both traits will be expressed.
 For example, if the Snork has chromosomes with genes for both blue and red pigment in skin (or
hair), the Snork will be purple.
Genes
Gene 1- body
covering
Gene Expression
Amino Acid Sequence
Phenotype/Trait
val – ser – leu
Hairless
val – ser – lys
Hairy
tyr – pro – glu – glu – lys
Plump
val – pro – thr – glu – lys
Skinny
leu –leu- ser-a la
2 legged
Dominant
leu – leu – leu – pro
3 legged
Recessive
ala – val- val
Round head
Dominant
val- ala- ala
Square head
Recessive
ser – pro – val
Blue pigment (hair/skin)
val – phe – tyr
Red pigment (hair/skin)
asp – ile – leu – leu – pro – thre
Brown eyes
Dominant
asp – ile – pro–pro – pro – thre
Purple eyes
Recessive
phe – phe – gly
Rounded floppy ears
Dominant
phe – ser – gly
Pointed standing-up ears
Recessive
Gene 2- body style
Incomplete
Dominance
Incomplete
Dominance
Incomplete
Dominance
Incomplete
Dominance
Gene 3- legs
Gene 4- head
shape
Gene 5- body
pigment
Gene 6- eyes
Gene 7 – ears
Incomplete
Dominance
Incomplete
Dominance
Name: ________________________________________
Codon Wheel
Name: ________________________________________
Snapple Snork
Using the table below, transcribe the DNA into mRNA and then translate the mRNA into amino acids. Use the codon
wheel to determine the amino acid sequence and thus the traits of your Snork. Draw your Snork on the back and
answer the questions.
Chromosome #
DNA Sequence
1
CAG TCG TTT
CAT AGA TTT
2
CAA GGG TGT CTT TTT
CAA GGA TGA CTT TTC
3
GAG AAT TCA CGC
GAA GAG GAG GGG
4
CAA CGC CGA
CAA CGC CGA
5
CAA AAA ATG
CAT AAA ATA
6
CTA TAA GGG GGG GGG TGG
CTA TAA GGG GGG GGG TGG
7
AAG AAA CCC
AAA AGA CCA
mRNA
1. Why does the Snork have two sets of chromosomes per gene?
Amino Acid Sequence
Trait
D/R/I?
D= Dominant
R=Recessive
I=Incomplete
Dominance
2. What are some traits in humans that might be dominant or recessive or incomplete dominant? How do you
know?
3. Compare and contrast your Snork to another Snork of your choosing (from your group). Do any traits have
similarities in phenotype but differences in the DNA sequence? Explain.
Name: ________________________________________
Snicker Snork
Using the table below, transcribe the DNA into mRNA and then translate the mRNA into amino acids. Use the codon
wheel to determine the amino acid sequence and thus the traits of your Snork. Draw your Snork on the back and
answer the questions.
Chromosome #
1
2
3
4
5
6
7
DNA Sequence
mRNA
Amino Acid Sequence
Trait
D/R/I?
CAG TCG TTT
CAT AGA TTT
ATG GGG CTT CTC TTT
ATG GGG CTC CTT TTT
GAG AAT TCA CGC
GAG AAT TCA CGC
CGA CAA CAC
CAA CGC CGA
CAA AAA ATG
AGA GGG CAT
CTA TAG AAT GAC GGG TGG
CTA TAA GGG GGG GGG TGG
AAA AGA CCA
AAG AGC CCA
1. Why does the Snork have two sets of chromosomes per gene?
D= Dominant
R=Recessive
I=Incomplete
Dominance
2. What are some traits in humans that might be dominant or recessive or incomplete dominant? How do you
know?
3. Compare and contrast your Snork to another Snork of your choosing (from your group). Do any traits have
similarities in phenotype but differences in the DNA sequence? Explain.
Name: ________________________________________
Snoopy Snork
Using the table below, transcribe the DNA into mRNA and then translate the mRNA into amino acids. Use the codon
wheel to determine the amino acid sequence and thus the traits of your Snork. Draw your Snork on the back and
answer the questions.
Chromosome #
DNA Sequence
1
CAT AGG GAG
CAG TCG GAA
2
ATG GGG CTC CTT TTT
CAA GGA TGA CTT TTC
3
4
5
6
7
mRNA
Amino Acid Sequence
Trait
D/R/I?
GAA GAG GAG GGG
AAT AAT GAC CGC
CGA CAA CAT
CAA CGC CGA
AGA GGG CAT
AGA GGG CAT
CTA TAA GGG GGG GGG TGG
CTA TAA GGG GGG GGG TGG
AAA AGA CCA
AAG AGC CCA
1. Why does the Snork have two sets of chromosomes per gene?
D= Dominant
R=Recessive
I=Incomplete
Dominance
2. What are some traits in humans that might be dominant or recessive or incomplete dominant? How do you
know?
3. Compare and contrast your Snork to another Snork of your choosing (from your group). Do any traits have
similarities in phenotype but differences in the DNA sequence? Explain.
Name: ________________________________________
Snuffle Snork
Using the table below, transcribe the DNA into mRNA and then translate the mRNA into amino acids. Use the codon
wheel to determine the amino acid sequence and thus the traits of your Snork. Draw your Snork on the back and
answer the questions.
Chromosome #
DNA Sequence
1
CAT AGG GAG
CAG TCG TTT
2
GAA GAG GAG GGG
CAA GGA TGA CTT TTC
3
4
5
6
7
mRNA
Amino Acid Sequence
Trait
Is it D/R/I?
GAA GAG GAG GGG
AAT AAT GAC CGC
CAA CGC CGA
CAA CGC CGA
CAT AAA ATA
AGA GGG CAT
CTA TAA GGG GGG GGG TGG
CTA TAA GGG GGG GGG TGG
AAG AAA CCC
AAG AAA CCC
1. Why does the Snork have two sets of chromosomes per gene?
D= Dominant
R=Recessive
I=Incomplete
Dominance
2. What are some traits in humans that might be dominant or recessive or incomplete dominant? How do you
know?
3. Compare and contrast your Snork to another Snork of your choosing (from your group). Do any traits have
similarities in phenotype but differences in the DNA sequence? Explain.