Name: _______________________
Period: _______________________
Date: _______________________
MUTATIONS LAB
Objectives:
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


To define different types of mutations.
To understand the three types of point mutations; silent, missense, and nonsense.
To understand how an addition or deletion of a nucleotide causes a frameshift mutation.
To understand the four types of chromosomal mutations; deletion, duplication, inversion,
translocation.
Mutations:
1. Define the following words: mutation, gene mutation, chromosomal mutation.
Gene Mutations:
1. Define Point Mutation.
2. The sentence below is analogous to a DNA sequence. Exchange the 1st letter in the 3rd word
with another letter and rewrite the sentence.
THE FAT CAT ATE THE WEE RAT.
3. How do you think point mutations affect amino acid sequences (proteins)?
4. Analyze the DNA and mRNA sequences below. What will the amino acid sequence be of the
normal DNA? Mutated DNA? Will the mutated DNA produce the same protein?
normal DNA: TACGCATGGAAT
mRNA: AUG CGU ACC UUA
amino acids:
mutated DNA: TACGTATGGAAT
mRNA: AUG CAU AGG UUA
amino acids:
When a point
mutation results in
a different amino
acid, it is called a
missense mutation.
5. Analyze the DNA and mRNA sequences below. What will the amino acid sequence be of the
normal DNA? Mutated DNA? Will the mutated DNA produce the same protein?
normal DNA: TACGCAACCAAT
mRNA:
amino acids:
mutated DNA: TAC GCA ACT AAT
mRNA:
amino acids:
When a point
mutation results in
a stop signal, it is
called a nonsense
mutation.
Name: _______________________
Period: _______________________
Date: _______________________
6. Analyze the DNA and mRNA sequences below. What will the amino acid sequence be of the
normal DNA? Mutated DNA? Will the mutated DNA produce the same protein?
normal DNA: TACGCAACCAAT
mRNA: AUG CGU UGG UUA
amino acids:
mutated DNA: TAC GCG ACC AAT
mRNA: AUG CGC UGG UUA
amino acids:
When a point
mutation results in
the same amino
acid, it is called a
silent mutation.
Gene Mutations:
1. Define Frameshift Mutation.
2. The sentence below is analogous to a DNA sequence. Add another letter after the “A” in “CAT”
and rewrite the sentence in groups of 3 letters.
THE FAT CAT ATE THE WEE RAT.
3. Delete the “A” in “CAT” and rewrite the sentence in groups of 3 letters.
THE FAT CAT ATE THE WEE RAT.
4. How do you think frameshift mutations affect amino acid sequences (proteins)?
5. Analyze the DNA and mRNA sequences below. What will the amino acid sequence be of the
normal DNA? Mutated DNA? Will the mutated DNA produce the same protein?
normal DNA: TAC GCA TGG AAT
mRNA: AUG CGU ACC UUA
amino acids:
mutated DNA: TATCGCATGGAAT
mRNA: AUA GCG UAC CUU A
amino acids:
An addition causes
a frameshift
mutation.
6. Analyze the DNA and mRNA sequences below. What will the amino acid sequence be of the
normal DNA? Mutated DNA? Will the mutated DNA produce the same protein?
normal DNA: TACGCATGGAAT
mRNA:
amino acids:
mutated DNA: TAGCATGGAAT
mRNA:
amino acids:
A deletion causes a
frameshift mutation.
Name: _______________________
Period: _______________________
Date: _______________________
Chromosomal Mutations:
1. The sentence below is analogous to a chromosome and each of the words is analogous to a
gene. Delete the 3rd word and rewrite the sentence.
A deletion involves
THE FAT CAT ATE THE WEE RAT.
the loss of all or part
of a chromosome.
2. How do you think deletions of a chromosome affect an organism?
3. The sentence below is analogous to a chromosome and each of the words is analogous to a
gene. Use the 3rd word twice and rewrite the sentence.
A duplication involves
THE FAT CAT ATE THE WEE RAT.
a segment of a
chromosome being
repeated.
4. How do you think duplications of a chromosome affect an organism?
5. The sentence below is analogous to a chromosome and each of the words is analogous to a
gene. Write the last three words of the sentence backwards and rewrite the sentence.
THE FAT CAT ATE THE WEE RAT.
An inversion involves
a segment of a
chromosome being
oriented in the wrong
6. How do you think inversions of a chromosome affect an organism?
direction.
7. The two sentences below are analogous to non-homologous chromosomes and each of the
words is analogous to a gene. Replace the last three words of each sentence with the last three
words of the other sentence and rewrite the new sentences.
THE MAD FAT CAT ATE THE WEE RAT.
A translocation
THE SAD DOG CAN NOT PAT THE BAT.
involves part of a
non-homologous
chromosome breaking
off and attaching to
another nonhomologous
8. How do you think translocations of a chromosome affect an organism?
chromosome.