Name: Date: Period:
Mutations Practice Worksheet
1. Define the following words:
Mutation
Gene
2. The basic 3 types of gene mutations are:
3. Transcribe the following โnormalโ DNA sequence into mRNA. Then use your codon chart to translate the
mRNA into amino acids. The normal DNA sequence represents a normal gene. Remember that a gene is a
sequence of DNA that codes for a particular protein.
Normal DNA Gene Sequence
DNA
T โ A โ C โ G โ C โ T โ T โ C โ G โ A โ A โ G โ C โ T โ C โ A โ A โ C โ G โ G โ C โ A โ C - T
mRNA
Amino
Acids
4. Mutation #1: Compare the mutated strand of DNA in the table below to the normal strand of DNA. What
difference do you notice?
Normal
DNA
T โ A โ C โ G โ C โ T โ T โ C โ G โ A โ A โ G โ C โ T โ C โ A โ A โ C โ G โ G โ C โ A โ C - T
Mutated
DNA
T โ A โ C โ G โ C โ A โ T โ C โ G โ A โ A โ G โ C โ T โ C โ A โ A โ C โ G โ G โ C โ A โ C โT
mRNA
Amino
Acids
1. This is an example of a __________________ mutation.
2. Base #_______ which was a _____ was substituted for a _____.
3. How many Amino Acids were changed by this mutation? _____
4. Did this mutation change the gene and therefore the overall protein that would be produced? Explain
why or why not.
SUBSTITUTION INSERTION DELETION
A CHANGE IN THE NUCLEOTIDE SEQUENCE IN THE GENETIC CODE FOR A PROTEIN
A NUCLEOTIDE SEQUENCE IN THE DNA THAT CODES FOR A TRAIT
A U G C G A A G C U U C G A G U U G C C G U G A
MET ARG SER
PHE GLU LEU PRO STOP
T WAS REPLACED BY A IN THE MUTATED SEQUENCE OF THE SECOND CODON
A U G C G U A G C U U C G A G U U G C C G U G A
MET ARG SER PHE GLU LEU PRO STOP
POINT/SUBSTITUTION/SILENT
6 T A
NONE
NO. IT WAS A SILENT MUTATION. EVEN THOUGH A BASE WAS SUBSTITUTED FOR ANOTHER
THE AMINO ACID FROM THAT MUTATION DID NOT CHANGE, NOT AFFECTING THE PROTEIN
