By the year 2010, 17.8 million youths aged 16-19 will work, up from 16 million in 2000, according to government forecasts. Young workers suffer a disproportionate share of injuries and fatalities, especially in the first year on the job. In 2006, 30 youths under 18 died from work-related injuries.
A mutation may or may not affect the amino acid sequence. A mutation may or may not affect the phenotype. Some specific mutations in a gene may have more adverse affects than other mutations in the same gene. A mutation is not necessarily bad. It may even be good. A mutation may enhance or positively change the function of the protein produced by the gene.
A mutation is a change in a DNA sequence that alters the protein for which the DNA codes. Sometimes mutations occur due to damage from an outside source, such as ultraviolet radiation. Excess ultraviolet radiation from the sun sometimes causes mutations that lead a cell to become cancerous. Most mutations that damage a DNA strand are harmful. Other mutations occur due to deletion or insertion of DNA base pairs. One such deletion in humans confers HIV resistance or a delayed AIDS onset. Humans who are heterozygous for the mutation, meaning they possess one mutant gene and one normal gene, experience a slower progression of AIDS.