CLONING

CLONES 2 organisms with identical DNA

Natural Clones Asexual Reproduction Binary Fission (Used by many single celled organsisms) Budding (Ball of cells formed by mitosis grows into individual organism. Ex: Hydra) Fragmentation – A piece breaks off & grows into full organism (Ex: Starfish) Identical Twins Totipotent Cells break off of embryo (Totipotent Cells have potential to become an entire organism…up until 8 cell stage in humans)

STEM CELLS Cells divide by mitosis & produce cells that will become more specialized

Kinds of Stem Cells: Embryonic: Adult: A Totipotent cell can become ANY kind of cell (up until 8 cell stage in humans) A Pleuripotent cell can become almost any kind of cell Adult: A Multipotent cell can become different kinds of cells, but only closely related cells (Ex: Blood Stem cell can give rise to any kind of Blood cell) Used to replace cells

DIPLOID (2n) versus HAPLOID (n) Diploid cells have the full number of chromosomes. This # is 46 in humans Haploid cells have ½ the number of the diploid #. This # is 23 in humans DIPLOID CELL HAPLOID CELL

Somatic Cells versus Sex Cells Somatic Cells are cells that make up the body (Ex: Skin cells, liver cells, bone cells, etc). Sex Cells are gametes (sperm & eggs in humans).

Embryo is placed in the uterus of a surrogate mother

Somatic Cell Nuclear Transfer (Cloning Technique) Take a Somatic Cell (Body Cell) from individual you want to clone Take an egg cell from female & enucleate it (take out nucleus) Bring body cell & enucleated cell close & zap with electricity (cells fuse together) Egg cell now diploid, so it thinks it’s fertilized & divides by mitosis to make embryo Place embryo in uterus of surrogate mother (female that carries another female’s baby)

CLONING TIMELINE