Mutations Worksheet
Name
Date: ________ Per. _____
During replication, transcription and translation there can be a mistake made in the bonding of complementary bases.
These mistakes will lead to mutations. There are three main types of mutations: point mutations, insertion, and deletion
mutations (the latter two are both frameshift mutations). In each of the following DNA sequences, you will use the
mRNA and amino acid sequences to identify the mutation that occurred. Amino acid chains will become proteins.
Remember back to the function of enzymes, which are proteins, and how a change in the shape of proteins will change
their ability to work. Now add to this thought, changing the sequence of amino acids in a chain can change how the
protein is folded and shaped, therefore changing its function. Use these sections of DNA to see what impact on the amino
acid sequence is achieved by the different mutations!
Original DNA Sequence:
T A C A C C T T G G C G A C G A C T
mRNA Sequence:
Amino Acid Sequence:
Mutated DNA Sequence #1:
T A C A T C T T G G C G A C G A C T
What’s the mRNA sequence?
(Circle the change)
What will be the amino acid sequence?
How many amino acids are different? ________ What kind of mutation is this?
Mutated DNA Sequence #2:
T A C G A C C T T G G C G A C G A C T
What’s the mRNA sequence?
(Circle the change)
What will be the amino acid sequence?
How many amino acids are different? ________
Mutated DNA Sequence #3:
What kind of mutation is this?
T A C A C C T T A G C G A C G A C T
What’s the mRNA sequence?
(Circle the change)
What will be the amino acid sequence?
How many amino acids are different? ________
Mutated DNA Sequence #4:
What kind of mutation is this?
T A C A C C T T G G C G A C T A C T
What’s the mRNA sequence?
(Circle the change)
What will be the amino acid sequence?
How many amino acids are different? ________
Mutated DNA Sequence #5:
What kind of mutation is this?
T A C A C C T T G G G A C G A C T
What will be the corresponding mRNA sequence?
What will be the amino acid sequence?
How many amino acids are different? ________
What kind of mutation is this?
Discussion Questions: (you may use your table partners)
1. If mutated DNA Sequence #1 occurred in a single cell on the membrane of a fish, how might it impact the
organism?
2. If mutated DNA Sequence #1 occurred in a single reproductive cell of a fish that was later fertilized to become an
offspring, how might it impact the organism?
3. If mutated DNA Sequence #2 occurred in a reproductive cell of a fish that was later fertilized to become an
organism. And the mutation occurred in a gene that coded for a hormone needed for growth, how might it impact
the organism?
4. If mutated DNA Sequence #1 occurred in a reproductive cell of a fish that was later fertilized to become an
organism. And the mutation occurred in a gene that coded for a pigment that normally appears blue and as a result
of the mutation appears red, how might it impact the organism?
5. DNA replication, transcription, and translation all have enzymes whose job it is to attach the complementary
nucleotides to an existing strand. Nonetheless, these enzymes do make mistakes at a rate of about 1 per
every 100,000 nucleotides. That might not seem like much, until you consider how much DNA a cell
has. In humans, with our 6 billion base pairs in each diploid cell, that would amount to how many
mistakes?