Heartworms are spread to dogs through mosquito bites. Up to 14 inches long, a heartworm lives in the heart and the arteries that carry blood from the heart to the lungs. Heartworms affect how the heart functions and how blood clots and is likely to cause death if untreated. Monthly heartworm preventives are effective.
missense mutation. A substitution of a single DNA nucleotide for another. This results in the transcription of a different amino acid than is normally found in the protein coded by the gene. Missense mutations are found in diseases such as sickle cell anemia.
This image shows an example of missense mutation. One of the nucleotides (adenine) is replaced by another nucleotide (cytosine) in the DNA sequence. This results in an incorrect amino acid (proline) being incorporated into the protein sequence.In genetics, a missense mutation (a type of nonsynonymous substitution) is a point mutation in which a single nucleotide change results in a codon that codes for a different amino acid.hen an amino acid may be encoded by more than one codon (so-called degenerate coding) a mutation in a codon may not produce any change in translation; this would be a silent mutation (a type of synonymous substitution, which is not always silent) and not a missense mutation.