This encyclopedia set, part of the Macmillan Science Library series, is intended for use by middle- and high-school students, college nonspecialists, and beginning researchers. More than 100 contributors are responsible for approximately 250 signed entries from Accelerated aging: Progeria to Zebrafish. Articles range from a few paragraphs to a few pages in length and focus on a variety of topics, including inheritance, genes and chromosomes, genetic diseases, biotechnology, history, careers, and the ethical, legal, and social issues associated with genetically modified foods and cloning. The entries appear in alphabetical order and include cross-references to related entries..