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20 hours ago · Vitamin A is a fat-soluble vitamin, hence an essential nutrient. The term "vitamin A" encompasses a group of chemically related organic compounds that includes retinol, retinal (also known as retinaldehyde), retinoic acid, and several provitamin (precursor) carotenoids, most notably beta-carotene.
20 hours ago · The first genetically modified crops, tobacco (Nicotiana) plants were grown in China in 1988. Gene therapy techniques became established by the end of the 1980s, allowing gene tagging and gene therapy to become a possibility, both of which were first performed in human beings in May 1989 and September 1990, respectively.
