Genetic research focuses on cloning and genetic engineering. Cloning involves creating genetically identical offspring from a single organism's cells, which has been done with plants and animals like Dolly the sheep. Genetic engineering transfers genetic material between organisms to create recombinant DNA and introduce new genes, which has been used to develop therapies for disorders like growth hormone deficiency and diabetes. Selective breeding techniques like inbreeding and hybridization are also used to improve plant and animal varieties.