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.
Definition of Missense Mutation. A mutation is a permanent change in a DNA sequence. DNA is the unit of heredity of all organisms, so this means that mutations can often be passed on to offspring. You probably associate the word mutation with something that is bad, but mutations don't have to be bad.