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.
Nonsense mutation. Definition. noun. A form of point mutation resulting in a nonsense codon that does not code for an amino acid and leads to a protein product that is early truncated. Supplement. In nonsense mutations, the protein product from a sequence of DNA with a nonsense mutation is prematurely truncated, incomplete and often nonfunctional.Genetic disease ...upplement. In nonsense mutations, the protein product from a sequence of DNA with a nonsense mutation is prematurely truncated, incomplete and often nonfunctional. Genetic disease such as Duchenne muscular dystrophy is caused by a nonsense mutation in gene responsible for a specific protein, for example, dystrophin.