Download Alien Encounters! Purpose: In this activity, you will determine the

Alien Encounters!
Purpose: In this activity, you will determine the traits of recovered aliens by analyzing their DNA
and determining the amino acid sequences of the resulting small protein fragments. Each
fragment is associated with a particular gene and a specific alien characteristic (trait).
Procedure:
1.
2.
3.
4.
5.
Put the DNA sequence for each gene in the proper location on your data sheet.
Transcribe the DNA for each gene into mRNA. Record those sequences.
Translate the mRNA into amino acids using the provided mRNA Codon Chart. Record the amino acid sequence for each
gene.
Use the “Alien Genes” chart to determine the traits that are associated with each of your amino acids sequences and write
those traits on the charts.
On the back of the Alien Genes chart, draw your alien and answer the following questions:
Questions:
1.
2.
3.
4.
5.
6.
Did you find any “identical” aliens in your group?
Give the tRNA sequences for Gene D.
How does a single change in a nitrogen base alter the formation of a resulting protein?
If you knew a particular amino acid sequence, could you figure out the DNA for that sequence?
What is the difference between transcription and translation?
What are the roles of the DNA, the mRNA, the rRNA, and tRNA in protein synthesis?
mRNA CODON CHART
DATA Tables for Alien Gene Analysis: Alien Number 1
Is your alien hairless or hairy?
GENE
A
DNA
CAAGGATAT
mRNA
Amino Acids
Trait
Is your alien fat or skinny?
GENE
B
DNA
ACCCAACAA
mRNA
Amino Acids
Trait
Does your alien have 4 legs or 8 legs?
GENE
C
DNA
AGCAGG
mRNA
Amino Acids
Trait
What size nose does your alien have?
GENE
D
DNA
GTCAGGAAACCC
mRNA
Amino Acids
Trait
Does your alien have antennae or not?
GENE
E
DNA
TTTAAA
mRNA
Amino Acids
Trait
What color skin does your alien have?
GENE
F
DNA
GGACGCCGA
mRNA
Amino Acids
Trait
How many fingers does your alien have?
GENE
G
DNA
GTCCTCCTA
mRNA
Amino Acids
Trait
Does your alien have 4 eyes or 8 eyes?
GENE
I
DNA
TATCTACGC
mRNA
Amino Acids
Trait
Does your alien have a tail?
GENE
H
DNA
CGCCCCTAT
mRNA
Amino Acids
Trait
ALIEN GENES
This table shows the amino acid sequences for the various alien genes and traits.
Gene
Letter
A
B
C
D
E
F
G
H
I
Amino Acid Sequence
Val-pro-ileu
Tryp-pro-ileu
Tryp-val-val
Ileu-ileu-ser
Ser-ala
Ser-ser
Pro-ser-phe-gly
Gln-ser-phe-gly
Lys-phe
Lys-leu
Pro-ala-ala
Pro-ala-asp
Pro-ala-val
Pro-ala-pro
Gln-glut-asp
Gln-glut-lys
Gly-gly-ileu
ala-gly-ileu
Ileu-asp-ala
Ser-asp-ala
Resulting Characteristic
Hairless
Hairy
Fat
Skinny
4 legs
8 legs
Long nose
Short nose
No antennae
4 antennae
Blue skin
Red skin
Yellow skin
Green skin
10 fingers
12 fingers
Tail
No tail
4 eyes
8 eyes