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Name __________________________________________Date ______________Period ____________
Mutation Lab
Directions: Select one baggie with foam squares. These foam squares are to represent the
nitrogen-containing bases of DNA (adenine, guanine, thymine, cytosine) and mRNA (adenine,
guanine, uracil, cytosine). Use your book to help guide you through this lab. When the type of
mutation represented is asked for, choose from the following mutations:
 Point mutation: a change in a single nucleotide
 Insertion mutation: a sizeable length of DNA is inserted into a gene
 Deletion mutation: segments of a gene are lost
1. On your desk, lay out the appropriate foam squares to represent the following DNA
chain:
T-A-C-C-G-C-T-T-G
2. Now, simulate transcription by laying out the foam squares that represent the nitrogencontaining bases that would combine with (are complementary to) the DNA chain from
#1. What is the complementary sequence of mRNA?
3. Refer to the chart on p. 211. What amino acids would be coded for by the mRNA strand in
#2?
4. Now you are going to mutate the DNA strand from #1. Choose one nitrogen-containing
base from the DNA sequence and delete it. Write down the DNA strand you are left with.
5. What type of mutation is illustrated in #4?
6. Now, simulate transcription with this mutated strand written down for #4 by adding
complementary foam squares to the DNA strand to make an mRNA strand. Write the
sequence of mRNA below.
7. Again, referring to the chart on p. 211, what is the amino acid sequence coded for by the
sequence of mRNA in #5 (remember: codons = triplets)
8. Now, examine the amino acid sequence in #3 compared to that of #7. What is the
difference? Based on this difference, how does the type of mutation identified in #5 affect
the proteins that are made?
9. Now we are going to mutate the original strand of DNA from #1 again. Lay the following
mutated DNA sequence out with your foam squares:
T-A-C-C-G-C-T-A-T-G
10. Compare the DNA strand in #9 with that of #1. Using p. 219 in your book, what type of
mutation is this? (Hint: Compare the number of nucleotides in both DNA strands).
11. Use the foam squares to identify the mRNA strand produced by transcription of the DNA
strand in #9? Write this sequence below.
12. Using the chart on p. 211, what is the amino acid sequence coded for by the mRNA strand
in #11?
13. What is the difference between the amino acid sequence in #3 and that of #12? Based on
this difference, how does the type of mutation identified in #10 affect the proteins that are
made?
14. Now, we will perform one final mutation of the DNA strand in #1. Lay out the following
mutated strand of DNA using your foam squares:
T-A-C-C-G-C-A-T-G
15. Compare the mutated DNA strand in #14 with that of the original, non-mutated DNA
strand in #1. What type of mutation is this, according to p. 219 in your book? (Hint: pay
special attention to the underlined nucleotide).
16. Using your foam squares, lay out the complementary mRNA sequence to this mutated
DNA strand in #14. Write the mRNA sequence below.
17. Again, referring to the chart on p. 211, what is the amino acid sequence coded for by the mRNA
sequence in #16?
18. Based on the different amino acid sequences in #3 and #17, how does this type of mutation
identified in #15 affect the proteins that are made?