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Mutation Homework
1. If the DNA codons are CAT CAT CAT, and a guanine base is added at the beginning, then which would
result?
(a) G CAT CAT CAT
(b) GCA TCA TCA T
(c) frameshift mutation
(d) b and c, but not a
2. A nonsense mutation:
(a) causes one amino acid to be substituted for another in a protein chain.
(b) results from the deletion of one or more bases, leading to a shift in the reading frame.
(c) results from the insertion of one of more bases, leading to a shift in the reading frame.
(d) usually results from the formation of an short protein
3. A point mutation:
(a) is a change in the nucleotide sequence of DNA.
(b) may be caused by environmental agents.
(c) may arise spontaneously.
(d) can occur in all organisms.
(e) all of the above.
4. Mutations can be:
(a) random.
(b) beneficial.
(c) deadly.
(d) inherited from parents.
(e) all of the above.
5. A frameshift mutation could result from:
(a) a base insertion only.
(b) a base deletion only.
(c) a base substitution only.
(d) deletion of three bases in a row.
(e) either an insertion or a deletion of a base..
6. Which of these statements represents a common misconception regarding point mutations?
(a) They involve changes in one base pair.
(b) They can cause drastic changes in protein.
(c) They always produce a change in the amino acid sequence of a protein.
(d) They can lead to a shorter protein.
7. Using the genetic code, identify the sequence of nucleotides in the DNA that would code for the amino acid
sequence Phenylalanine-Proline-Lysine.
(a) AAA-GGG-UUU
(b) TTC-CCC-AAG
(c) TTT-CCA-AAA
(d) AAG-GGC-TTC
(e) UUU-CCC-AAA
True/False:
8. True or False:
Mutations in body cells are not passed on to the next generation.
9. True or False:
All point mutations occur when an AT base pair is substituted with a GC base pair.
10. Using the base-pairing rules, fill in the mRNA sequence that would be transcribed from the following strand
of DNA. Then use the Codon wheel to determine the amino acid sequence that would be translated when the
mRNA combines with a ribosome:
A—T--T--A--C--A--A--G--T--A--C--T--T--G--T--T--T--C--T—T—A – C—C -- G
mRNA codons: _______________________________________________________________________
amino acids: _________________________________________________________________________
tRNA anticodons: ______________________________________________________________________
11. Suppose the three guanine (G) nucleotides in Question 10 were changed to cytosine (C) nucleotides. What
would be the new amino acid sequence? What type of mutation is this?
12. Suppose the G nucleotides were removed from the DNA in Question 10. What would be the new amino
acid sequence? What type of mutation is this?
13. How many base-pairs would have to be deleted in a eliminate a single amino acid from a protein and not
change the rest of the protein?
14. CHALLENGE: Using the DNA from number 10, show a NONSENSE mutation. Write the mutated DNA,
the corresponding mRNA, and the new amino acid sequence that results.