How DNA determines the traits of an organism Lab
The Snork brothers have been sneaking around town and committing many crimes. They have
stolen cars, robbed banks, and stolen candy from babies. The brothers go by the names
Snicker, Snuffle, Snapple, and Snoopy. Luckily, traces of their DNA were left at the crime
scene. It is your job to analyse the DNA and determine how each stork looks to help the police
capture them.
In this simulation, you will examine the RNA sequence of a fictitious organism - the snork.
Snorks were discovered on the planet Dee Enae in a distant solar system. Snorks only have
one chromosome with 10 genes on it. Your job is to analyse the genes of its DNA to determine
what traits each snork has, and then sketch the snorks.
For simplicity, the gene sequences are much smaller than real gene sequences found in living
organisms. Each gene has 2 versions that result in a different trait being expressed in the snork.
Gene
Trait
1
body covering
2
body style
3
legs
4
head shape
5
tails
6
body pigment
7
eyes
8
mouth
9
ears
10
arms
Amino Acid Sequence
val - ser - leu
val - ser - lys
tyr - pro - gln - gln - lys
val - pro - thr - gln - lys
leu - leu - leu - pro
leu - leu - ser - ala
ala - val - val
val - ala - ala
his - iso
his - his
ser - pro - val
val - phe - tyr
asn - iso - leu - leu - pro - thr
asn - iso - pro - pro - pro - thr
val - asn - asn - ala
asn - asn - asn - ala
phe - ser - his
phe - phe - his
arg - tyr - cys - lys
arg - arg - asp - thr
Description
hairless
hairy
plump
skinny
3 legged
2 legged
round head
square head
tail
no tail
blue pigment (hair/skin)
red pigment (hair/skin)
small slanted eyes
large round eyes
circular mouth
rectangular mouth
pointed standing-up ears
rounded floppy ears
long spaghetti like arms
short stumpy arms
Each of the following RNA samples were found at the crime scenes. Analyse each tRNA code
and determine the snork’s phenotype based on the sequence of amino acids. Remember that
AUG is a start codon, and UAA, UAG and UGA are stop codons. The genes are in order from
gene 1–10. For each snork brother, fill in the table of his characteristics on the next page by
placing checks in the boxes of the traits he has. Then sketch and color a depiction of each
brother in the wanted posters.
Snicker Snork: AUG – GUC AGC AAA – UAC CCC CAA CAA AAA – CUC UUA AGU GCA –
GCU GUU GUG – CAU CAC – GUU UUU UAC – AAU AUC CCU CCU CCC ACC – GUC AAC
AAU GCC – UUU UCU CAC – CGA UAU UGU AAA – UAA
Snuffle Snork: AUG – GUA UCU AAA – GUU CCU ACU CAA AAG – CUU CUC CUC CCC –
GUU GCG GCU – CAC CAU – GUA UUC UAU – AAU AUU CUU CUG CCC ACA – AAU AAU
AAU GCA – UUC UCG CAC – AGA CGU GAU ACU – UAG
Snapple Snork: AUG – GUC AGC AAA – UAC CCC CAA CAG AAG – CUC UUA AGC GCG –
GUU GCG GCU – CAC AUU – UCU CCC GUA – AAU AUU CUC CUC CCC ACC – GUU AAU
AAU GCA – UUC UUU CAU – CGC UAC UGU AAA – UAA
Snoopy Snork: AUG – GUG UCC CUC – UAC CCC CAA CAG AAA – UUA UUG CUG CCC –
GUG GCA GCU – CAU AUC – UCC CCU GUU – AAC AUU CCA CCG CCC ACA – AAU AAC
AAU GCC – UUU UCU CAC – CGG UAU UGC AAG – UGA
Gene
Trait
1
body covering
2
body style
3
legs
4
head shape
5
tails
6
body pigment
7
eyes
8
mouth
9
ears
10
arms
Description
hairless
hairy
plump
skinny
3 legged
2 legged
round head
square head
tail
no tail
blue pigment (hair/skin)
red pigment (hair/skin)
small slanted eyes
large round eyes
circular mouth
rectangular mouth
pointed standing-up ears
rounded floppy ears
long spaghetti like arms
short stumpy arms
WANTED
Name: ___________________________________
Snicker Snuffle Snapple Snoopy
WANTED
Name: ___________________________________
WANTED
Name: ___________________________________
WANTED
Name: ___________________________________
Questions
1.
What are the three differences between RNA and DNA?
2.
Where is DNA found in the cell?
Where is RNA
found in the cell?
3.
Name the three types of RNA and what they do.
4.
Draw an mRNA strand that is complementary to the DNA strand AATTGC. Circle a
nucleotide.
5.
What are the steps of transcription?