5.19B describe the stages in the production of cloned mammals involving the introduction of a diploid nucleus from a mature cell into an enucleated egg cell, illustrated by Dolly the sheep

- The first mammal to be successfully cloned from a mature adult cell was a sheep called Dolly in 1996.
- Clone: a group of genetically identical organisms/cells derived from a single original cell.

Method:
1. The nucleus of a sheep's egg cell is removed, creating an enucleated cell.
2. A diploid nucleus from another sheep's body cell is inserted in its place.
3. The cell is stimulated by an electric shock to promote dividing by mitosis as if it was a normal fertilized egg.
4. The dividing cell is implanted into the uterus of another sheep to develop until it is ready to be born.
This was how Dolly was born.