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DNA Mutation Consequences Worksheet
Instructions
Fill in the blanks in each of the charts below.
Original DNA Sequence
Original DNA Sequence:
T A C G T G T T A G T C T A A G A A A C T
Number of Nucleotides:
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21
mRNA from Original DNA
mRNA Sequence:
a u g c a c a a u c a g a u u c u u u g a
Amino Acid Sequence
Amino Acid Sequence:
methionine histidine asparagine glutamine isoleucine leucine stop
Note: The 5' end is located at nucleotide 1 and the 3' end is located at nucleotide 21.
Mutation Examples
A) Substitute DNA Nucleotide 12 with T
Mutated DNA Sequence:
t a c g t g t t a g t t t a a g a a a c t
mRNA from Mutated DNA:
a u g c a c a a u c a a a u u c u u u g a
Amino Acid Sequence:
methionine histidine asparagine glutamine isoleucine leucine stop
1. Mutation Analysis
Did this mutation cause a change in the Amino Acid sequence?
No, it doesn't; the amino acid still codes for glutamine.
Category and Type of Mutation:
This is a silent point mutation. The sequence changes, but not the amino acid.
B) Substitute DNA Nucleotide 10 with C
Mutated DNA Sequence:
t a c g t g t t a c t c t a a g a a a c t
mRNA from Mutated DNA:
a u g c a c a a u g a g a u u c u u u g a
Amino Acid Sequence:
methionine histidine asparagine glutamic acid isoleucine leucine stop
2. Mutation Analysis
Did this mutation cause a change in the Amino Acid sequence?
Yes, it did change; the amino acid now codes for glutamic acid.
Category and Type of Mutation:
We would call this a missense point mutation.
C) Substitute DNA Nucleotide 10 with A
Mutated DNA Sequence:
t a c g t g t t a a t c t a a g a a a c t
mRNA from Mutated DNA:
a u g c a c a a u u a g
Amino Acid Sequence:
methionine histidine asparagine stop
3. Mutation Analysis
Did this mutation cause a change in the Amino Acid sequence?
Yes, this did change; the amino acids stop.
Category and Type of Mutation:
We call this a nonsense point mutation.
Further Mutations and Their Analysis
D) Delete DNA Nucleotide 4
Original Sequence:
T A C G T G T T A G T C T A A G A A A C T
Mutated DNA Sequence:
t a c t g t t a g t c t a a g a a a c t
mRNA from Mutated DNA:
a u g a c a a u c a g a u u c u u u g a
Amino Acid Sequence:
methionine threonine isoleucine arginine phenylalanine phenylalanine
4. Mutation Analysis
Did this mutation cause a change in the Amino Acid sequence?
Yes, this did change; the amino acid changed completely after methionine.
Category and Type of Mutation:
This is called a deletion frameshift.
E) Insert DNA Nucleotide G BETWEEN Nucleotide 3 and 4
Mutated DNA Sequence:
t a c g g t g t t a g t c t a a g a a a c
mRNA from Mutated DNA:
a u g c c a c a a u c a g a u u c u u u g a
Amino Acid Sequence:
methionine proline glutamine serine aspartic acid serine leucine
5. Mutation Analysis
Did this mutation cause a change in the Amino Acid sequence?
Yes, it changed all except for methionine.
Category and Type of Mutation:
This is a frameshift insertion.
F) Insert DNA Nucleotides GTG BETWEEN Nucleotide 3 and 4
Mutated DNA Sequence:
T A C G T G G T G T T A G T C T A A G A A
mRNA from Mutated DNA:
a u g c a c c a c a a u c a g a u u c u u
Amino Acid Sequence:
methionine histidine histidine asparagine glutamine isoleucine leucine
6. Mutation Analysis
Did this mutation cause a change in the Amino Acid sequence?
No, it didn't change the amino acid strand; it just added an extra amino acid sequence that didn’t mess up any of the other codons.
Category and Type of Mutation:
This is what we call a structural duplication where they are doubled.
Potential Questions
7. Is it possible to have a mutation in nucleotide 4 that would produce the same amino acid?
Explanation:
Yes, it is possible. A mutation in the fourth nucleotide could result in a different codon that still codes for the same amino acid.
8. Could any mutations have occurred in nucleotide 6 that would produce the same amino acid as the original?
Explanation:
Yes, it would be a silent mutation. It is possible for the sixth nucleotide to produce the same amino acid as the original.