Question

analysis: making sense of your data, your gene: ocaa individual # _8__

mutation	mutation type	cite your evidence here for mutation type
mutation 2	missense	the aa was changed
mutation 3	silent	same aa

1. which of the above mutations caused a change in the phenotype?
2. how did this change occur?
3. which mutation did not result in a change in the phenotype?

Explanation:

Question 4

Nonsense mutations introduce a premature stop codon, truncating the protein, and missense mutations change an amino acid (AA), which can alter protein function/structure. Silent mutations don't change the AA. So Mutation 1 (Nonsense) and Mutation 2 (Missense) can cause phenotype change as they alter protein (Nonsense: truncated; Missense: AA change).

For Mutation 1 (Nonsense): A codon becomes a stop codon, truncating the polypeptide (protein) prematurely, changing its structure/function. For Mutation 2 (Missense): A codon change leads to a different amino acid in the protein, altering its structure/function (e.g., enzyme activity, protein - protein interactions). Either (or both) mechanisms explain the phenotype change.

Silent mutations (Mutation 3) have the same codon - amino acid pairing (due to genetic code redundancy), so the protein's amino acid sequence remains unchanged. Thus, the protein structure/function is unaffected, so no phenotype change.

Answer:

Mutation 1 (Nonsense) and Mutation 2 (Missense) caused a change in the phenotype. (If choosing one most probable, Mutation 1 or 2; e.g., Mutation 1: Nonsense mutation truncates protein, Mutation 2: Missense changes AA, both alter phenotype. Silent (Mutation 3) doesn't.)

Question 5