Name________________________________ Date_______________Period________
Mutation Website Assignment
Go to the website: http://evolution.berkeley.edu/evolibrary/article/0_0_0/mutations_01
which you can access from my website links under Biology: DNA and Protein Synthesisit is the link titled “Mutations”.
1. Name the three possible effects of a substitution mutation (in which one
nucleotide is replaced with another such an A to a G).
For question 2, use the genetic code provided below which shows the amino acid
added for each mRNA codon .
2. A DNA triplet is ACG which is transcribed into an mRNA codon UGC and causes the
amino acid cysteine to be added to the protein in translation. Explain the effect of each
of the following substitution mutations. Remember to determine what mRNA codon
would be transcribed by each of the mutated DNA triplets and then use the charts on
the previous page to see what is encoded by the mRNA codon.
A. If ACG is mutated to AGG.
B. If ACG is mutated to ACA.
Use the DNA sequence, mRNA transcript and amino acid sequence for question 3.
DNA triplets sequence:
G A G
T A T
mRNA codons:
C U C
A U A
G G C
C C G
A T A
U A U
C A C
A G A
G U G
U C U
amino acid sequence:
LEU
ILE
PRO
TYR
VAL
SER
3. If a deletion mutation occurs were the first T is missing, determine the new order of
DNA triplets, the mRNA codons that would be transcribed and the amino acids that
would be translated (using the genetic code chart for mRNA to amino acids)
DNA triplet sequence:
G A G
A _ _
mRNA codon sequence:
_ _ _
_ _ _
amino acid sequence:
_ _ _
_ _ _
_ _ _
_ _ _
_ _ _
_ _ _
_ _ _
_ _ _
4. Why is a deletion mutation of a single nucleotide, like the one in question 3 called a
frameshift mutation. Explain how a frameshift mutation affects the protein that is
translated, compared to a substitution mutation.
5. Name two different causes of mutations.
6. Explain the difference between a somatic mutation and a germ line mutation
(include both the definition of each and the implications for the inheritance of the
mutated gene).
7. Name a negative effect of sickle cell anemia for each of the following levels
A. At the protein level
B. At the cellular level
C. At the whole organism level
8. Being a carrier of the sickle cell anemia allele has a positive effect (which explains
why this genetic disorder is most common among people who come from tropical areas
have certain strains of mosquitoes.) Explain what this positive effect is.
9. Give a weird fact about how a mutation in a control gene can affect an organism.
10. Explain the Lederberg experiment. What did these two scientists do, what were
the results, and what conclusions did they draw from these results?