© Lesson Plans Inc. 2007
© Lesson Plans Inc. 2007
© Lesson Plans Inc. 2007
com
Summary: Students will learn about frame shift mutations and base substitution
mutations.
Goals & Objectives: Students will be able to demonstrate how mutations change the
amino acid sequence. Students will be able to explain the difference between mutations.
Standards: CA Biology 4c. Students know mutations in the DNA sequence of a gene
may or may not affect the expression of the gene or the sequence of amino acids in an
encoded protein.
Prerequisite Knowledge: Students know the rules for DNA / RNA base pairing.
Students know what are protein synthesis, purines, pyrimidines, and how to use a codon
table.
Materials:
Procedures:
1. Review with the class about point mutations and the differences between frame shift
and base substitution.
2. Students work on the handout by themselves.
Accommodations: Students with an IEP can take the handout home if they need extra
time, and/or do questions 1 - 3 and questions 11 - 24.
Evaluation:
Each line with and underline is worth one point for a total of 25 points. Students should
have circled the mutated DNA or amino acid to help speed up grading.
Date:_____________ Period:______
FRAMESHIFT MUTATIONS
The insertion shifts the reading frame to the right. The deletion frame shifts the reading
frame to the left. Insert a letter C for the two insertion questions and for the deletion
questions, delete the H or one base letter.
DNA Sentence THE BOY CUT HIS LIP AND ATE THE HOT DOG
Insertion THE BOY ____ ____ ____ ____ ____ ____ ____ ____
٨
Deletion THE BOY CUT ____ ____ ____ ____ ____ ____ ____
٧
Now use real DNA code and translate it into the correct amino acids. Decide where in
the original DNA code to cause a mutation on the rest of the questions. Please use the
codon table on the last page to find the corresponding amino acids.
Write each codon per line and circle the mutated DNA base where the mutation took place.
Original DNA TAC GGA CGA TCT CAG GAG CCT ATA ATC
Insertion DNA _____ _____ _____ _____ _____ _____ _____ _____ _____
Mutated mRNA _____ _____ _____ _____ _____ _____ _____ _____ _____
Mutated Amino Acids _____ _____ _____ _____ _____ _____ _____ _____ _____
Original Amino Acid Met Pro Ala Arg Val Leu Gly Tyr STOP
Deletion DNA _____ _____ _____ _____ _____ _____ _____ _____ _____
Mutated mRNA _____ _____ _____ _____ _____ _____ _____ _____ _____
Mutated Amino Acids _____ _____ _____ _____ _____ _____ _____ _____ _____
Original Amino Acid Met Pro Ala Arg Val Leu Gly Tyr STOP
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A different type of gene mutation is called base substitution. It is the simplest type of
mutation where a nucleotide pair is replaced with a different nucleotide pair.
Base Substitution GAC → GGC
Use the DNA code below to demonstrate a purine → pyrimidine transversion mutation.
All you have to do is change one DNA base.
Write each codon per line and circle the mutated amino acid.
Original DNA TAC CAT GCA GAT CTG GCC CAG TTC ATC
Transversion DNA _____ _____ _____ _____ _____ _____ _____ _____ _____
Mutated mRNA _____ _____ _____ _____ _____ _____ _____ _____ _____
Mutated Amino Acid _____ _____ _____ _____ _____ _____ _____ _____ _____
Original Amino Acid Met Val Arg Leu Asp Arg Val Lys STOP
Use the DNA code below to demonstrate a purine → purine transition mutation. All you
have to do is change one DNA base.
Write each codon per line and circle the mutated amino acid.
Original DNA TAC GTC GCT CAA CGG GAC CTG ACC ACT
Transition DNA _____ _____ _____ _____ _____ _____ _____ _____ _____
Mutated mRNA _____ _____ _____ _____ _____ _____ _____ _____ _____
Mutated Amino Acid _____ _____ _____ _____ _____ _____ _____ _____ _____
Original Amino Acid Met Gln Arg Val Ala Leu Asp Trp STOP
A third type of base substitution is called silent mutation. Silent mutation happens when
one base in a codon is changed but both code for the same amino acid.
DNA CTT → CTG
Amino Acid Leu → Leu
Use the DNA code below to demonstrate a silent mutation. All you have to do is change
one DNA base but the amino acid stays the same.
Write each codon per line and circle the mutated DNA base.
Original DNA TAC CAT TCT CGG TGT AAA AGG GCG ATT
Silent DNA _____ _____ _____ _____ _____ _____ _____ _____ _____
Mutated mRNA _____ _____ _____ _____ _____ _____ _____ _____ _____
Mutated Amino Acid _____ _____ _____ _____ _____ _____ _____ _____ _____
Original Amino Acid Met Val Arg Ala Thr Phe Ser Arg STOP
Write each codon per line and circle the mutated amino acid.
Original DNA TAC GGT AAT CAA ATA GAA CCT GAG ACT
Nonsense DNA _____ _____ _____ _____ _____ _____ _____ _____ _____
Mutated mRNA _____ _____ _____ _____ _____ _____ _____ _____ _____
Mutated Amino Acid _____ _____ _____ _____ _____ _____ _____ _____ _____
Original Amino Acid Met Pro Leu Val Tyr Leu Gly Leu STOP
Please explain the difference between a frame shift mutation and a base substitution
mutation.
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Codon Table
FRAMESHIFT MUTATIONS
The insertion shifts the reading frame to the right. The deletion frame shifts the reading
frame to the left. Complete the following lines for frame shift mutations.
DNA Sentence THE BOY CUT HIS LIP AND ATE THE HOT DOG
Insertion THE BOY CCU THI SLI PAN DAT ETH EHO TDO
C
Comment [S1]: Insert base C
٨
Deletion THE BOY CUT ISL IPA NDA TET HEH OTD OG Comment [S2]: Delete base H
٧
Now use real DNA code and translate it into the correct amino acids. Decide where in
the original DNA code to cause a mutation on the rest of the questions. Please use the
codon table on the last page to find the corresponding amino acids.
Write each codon per line and circle the mutated DNA base where the mutation took place. Comment [S3]: Students can choose
where to insert a new base anywhere
Original DNA TAC GGA CGA TCT CAG GAG CCT ATA ATC which will cause different answers.
Mutated mRNA _____ _____ _____ _____ _____ _____ _____ _____ _____
Mutated Amino Acids _____ _____ _____ _____ _____ _____ _____ _____ _____
Original Amino Acid Met Pro Ala Arg Val Leu Gly Try STOP
Write each codon per line and circle the mutated DNA base where the mutation took place. Comment [S4]: Students can choose
where to delete a base anywhere.
Original DNA TAC GGA CGA TCT CAG GAG CCT ATA ATC
Deletion DNA _____ _____ _____ _____ _____ _____ _____ _____ _____
Mutated mRNA _____ _____ _____ _____ _____ _____ _____ _____ _____
Mutated Amino Acids _____ _____ _____ _____ _____ _____ _____ _____ _____
Original Amino Acid Met Pro Ala Arg Val Leu Gly Try STOP
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A different type of gene mutation is called base substitution. It is the simplest type of
mutation where a nucleotide pair is replaced with a different nucleotide pair.
Base Substitution GAC → GGC
Use the DNA code below to demonstrate a purine → pyrimidine transversion mutation.
All you have to do is change one DNA base.
Write each codon per line and circle the mutated amino acid.
Original DNA TAC CAT GCA GAT CTG GCC CAG TTC ATC
Transversion DNA _____ _____ _____ _____ _____ _____ _____ _____ _____
Mutated Amino Acid _____ _____ _____ _____ _____ _____ _____ _____ _____
Original Amino Acid Met Val Arg Leu Asp Arg Val Lys STOP
Use the DNA code below to demonstrate a purine → purine transition mutation. All you
have to do is change one DNA base.
Write each codon per line and circle the mutated amino acid.
Original DNA TAC GTC GCT CAA CGG GAC CTG ACC ACT
Transition DNA _____ _____ _____ _____ _____ _____ _____ _____ _____
Mutated mRNA _____ _____ _____ _____ _____ _____ _____ _____ _____
Mutated Amino Acid _____ _____ _____ _____ _____ _____ _____ _____ _____
Original Amino Acid Met Gln Arg Val Ala Leu Asp Trp STOP
A third type of base substitution is called silent mutation. Silent mutation happens when
one base in a codon is changed but both code for the same amino acid.
DNA CTT → CTG
Amino Acid Leu → Leu
Use the DNA code below to demonstrate a silent mutation. All you have to do is change
one DNA base but the amino acid stays the same.
Write each codon per line and circle the mutated DNA base.
Original DNA TAC CAT TCT CGG TGT AAA AGG GCG ATT
Silent DNA _____ _____ _____ _____ _____ _____ _____ _____ _____
Mutated mRNA _____ _____ _____ _____ _____ _____ _____ _____ _____
Original Amino Acid Met Val Arg Ala Thr Phe Ser Arg STOP
A base mutation that creates a new stop codon in place of an amino acid is called a
nonsense mutation.
DNA TGT → TGA
Amino Acid Cys → STOP
Use the DNA code below to demonstrate a nonsense mutation. All you have to do is
change one DNA base to create a new stop codon.
Write each codon per line and circle the mutated amino acid.
Original DNA TAC GGT AAT CAA ATA GAA CCT GAG ACT
Nonsense DNA _____ _____ _____ _____ _____ _____ _____ _____ _____
Mutated mRNA _____ _____ _____ _____ _____ _____ _____ _____ _____
Mutated Amino Acid _____ _____ _____ _____ _____ _____ _____ _____ _____
Original Amino Acid Met Pro Leu Val Tyr Leu Gly Leu STOP
Please explain the difference between a frame shift mutation and a base substitution
mutation.
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