Proteins are not built directly form genes. The working instructions of the genes are made of molecules of ribonucleic acid, or RNA. RNA, like DNA, is a nucleic acid. It differs from DNA in 3 ways. First, RNA consists of a single strand of nucleotides instead of the two strands that form the double helix. Second, RNA contains the five-carbon sugar ribose rather than the sugar deoxyribose. And third, RNA has a nitrogen-containing base called uracil …showed first 75 words of 422 total…

…showed last 75 words of 422 total…Some mutations are chemical mishaps that arise spontaneously. Other mutations, however, are induced by exposure to environmental agents called mutagens. Mutagens include ionizing radiation, ultraviolet light, and certain chemicals or irritants referred to as carcinogens. Carcinogens are cancer-causing agents such as asbestos (fibers used in insulation), benzene (a liquid used in making detergents, plastics, and paints), and other industrial pollutants. An oncogene is a gene that, when mutated, can cause a cell to become cancerous.