Final answer:
Incorrect placement of a codon due to mutations can lead to altered proteins with potentially severe effects on the organism, including insertion and nonsense mutations, or missense mutations that result in diseases like sickle-cell anemia. The genetic code's redundancy, or degeneracy, can reduce the impact of such mutations, but frameshift mutations usually result in nonfunctional proteins.
Step-by-step explanation:
When a codon is incorrectly placed during DNA replication or transcription, various types of mutations can occur, affecting the organism that carries it. In an insertion mutation, additional nucleotides are inserted into the DNA sequence, altering the subsequent codons and potentially leading to a frameshift. This can significantly affect protein function since the entire amino acid sequence after the mutation may change.
A nonsense mutation is another consequence where a codon is changed into a stop codon, causing translation to end prematurely. This usually results in a nonfunctional or truncated protein. Similarly, a missense mutation leads to the substitution of one amino acid for another, which can have severe effects depending on the importance of the amino acid replaced, as seen in diseases like sickle-cell anemia.
The genetic code has a certain level of redundancy, known as degeneracy, which can mitigate the impact of mutations. However, mutations that lead to unassigned codons or change the reading frame by not being a multiple of three nucleotides can result in nonfunctional proteins due to incorrect amino acid sequences or premature stop codons. The extent to which such mutations affect the species depends on their location in the gene and their impact on the protein's functionality.