DNA directs a cell's activities and determines a cell's characteristic. This vast amount of vital information encoded in DNA is organized into genes. A gene is a segment of DNA that transmits information from parent to offspring. When a cell prepares to divide, the DNA molecule coils and twists into a dense structure called a chromosome. A chromosome is a rod-shaped structure that forms when a single DNA molecule and its associated proteins coil tightly …showed first 75 words of 739 total…

…showed last 75 words of 739 total…called a deletion. As a result of deletion, a new cell will lack a certain set of genes. In a mutation called a duplication, the chromosome fragment attaches to its homologous chromosome, which will then carry two copies of a certain set of genes. Sometime the fragment reattaches to the original chromosome in the reverse orientation, producing a mutation called an inversion. Or, the fragment may join a nonhomologous chromosome, in an event called translocation.