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 Synthesis- it 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 G G C A T A C A C A G A
mRNA codons:
C U C A U A C C G U A U G U G U C U
amino acid sequence:
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?