DNA (deoxyribonucleic acid) is a substance containing genetic
information that is found inside the center (nucleus) of cells. DNA determines
what features a person inherits from his or her parents, such as blood type,
hair color, eye color, and other characteristics.
Chromosomes are parts of body cells that carry the DNA. Each
person's DNA contains tens of thousands of genes.
Defects in DNA are called genetic or chromosome defects or
disorders. These defects may cause changes in certain body processes or
functions. These changes may be harmless and undetectable, or they may cause
genetic diseases or disorders, such as hemophilia, cystic fibrosis, or Down
syndrome.
