DNA. complementary DNA (cDNA), copy DNA DNA transcribed from a specific RNA through the action of the enzyme reverse transcriptase. mitochondrial DNA (mtDNA) the DNA of the mitochondrial chromosome, existing in several thousand copies per cell and inherited exclusively from the mother.
Castor Oil. Castor oil is another good treatment for dry and chapped lips. Simply apply castor oil to your lips several times a day. You can also make a soothing treatment using one teaspoon of castor oil, one teaspoon of glycerin and a few drops of fresh lemon juice.
Medical Definition of Chapped lips. Chapped lips: Dry, cracked or sore lips, usually in cold, windy, dry weather and less often in warm weather. Sun exposure can contribute to chapping of the lips. Licking or biting the lips is often a contributing factor. The lips are more sensitive to chapping than the skin.