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.
Silent mutations - are caused by a point mutation & have no effect of the function because they code for the same amino acid. Missense mutations - are caused by a point mutation & result in a different amino acid to be placed in the protein. Nonsense mutations - a caused by a point mutation & cause a stop where there should not be one. Frameshift mutations - are caused by an insertion or deletion of a nucleotide causing the reading frame to shift & the protein to be too long or too short.