加拿大高三生物克隆.pptVIP

Unit: Mitosis Meiosis Chapter 17 Let’s Discuss... CLONING! What is it? Cloning: the process of forming IDENTICAL offspring from a single cell or tissue in the parent organism. It comes from 1 parent cell, and they have identical nuclear DNA. However Mutations can happen! As well, we do not see a variation of traits as we would with regular sexual reproduction. Cloning is a form of ASEXUAL REPRODUCTION! For a cell to produce an organism, it needs to be Totipotent This means that the DNA has the ability to support the development from egg to adult. Once the cells start dividing, they aren’t totipotent anymore. Usually, this is when it is 8 cells Some Technology 1958: Fredrick Stewart He produced a plant from ONE CARROT CELL! His technique became known as cloning. ex) Orchids are produced this way HOLD ON! How is this even possible? ONE CELL becoming a plant? I don’t think so... But.. if DNA has an entire complement of chromosomes per cell.. isn’t it possible? Animal Cloning Robert Briggs and Thomas King They worked with frogs, basically they sucked out the nucleus from an unfertilized egg cell (enucleated it) using a micropipette So what? THEN they took an embryo in the blastula stage AND PUT IT INTO THE ENUCLEATED CELL! Mad scientists anyone? It continued to divide much like a normal frog egg, and then it grew into an adult frog! Note: Only nucleic DNA will be cloned. The mtDNA comes from the donor egg. However, if the cells were at later stages of development,the embryo did not develop as well as in the blastula stage. Basically, specialized cells stay that way. During gastrulation the cells already have jobs. Hello Dolly Dr. Ian Wilmut He extracted the nucleus from an udder cell of an adult Finn Dorsett sheep, placed it into an enucleated egg from a Poll Dorsett and then developed it in a petri dish. Finally, he implanted it into the womb of a Scottish Blackface. The resulting lamb was identical to the Finn Dorsett genetically. Morals and Ethics What’s th