A yeast artificial chromosome (YAC) is a man-made DNA molecule used in genetic research to clone large pieces of DNA up to 1 million base pairs. Synonyms for YAC are chromosome libraries, human artificial chromosomes (HAC), bacterial artificial chromosomes (BAC), and PAC clones. These technologies allow scientists to study, manipulate and identify genes on a large scale. HACs are used for gene therapy applications, while BAC and PAC clones are used extensively in genetic engineering, transgenics, and recombinant DNA technology. YACs are also used in the production of biofuels, biodegradable plastics, and many other industrial applications. Synonyms for YACs highlight their versatility and usefulness across various fields of research and industry.