6.2.5: Cloning (biology only)
Not started yet — this one needs some love.
Tissue culture uses small groups of cells from part of a plant to grow identical new plants.
Tissue culture is important for preserving rare plant species or commercially in nurseries.
Cuttings are an older, simple method used by gardeners to produce many identical new plants from a parent plant.
Embryo transplants involve splitting apart cells from a developing animal embryo before they become specialised.
In embryo transplants, identical embryos are transplanted into host mothers.
Adult cell cloning begins when the nucleus is removed from an unfertilised egg cell.
The nucleus from an adult body cell, such as a skin cell, is inserted into the egg cell.
An electric shock stimulates the egg cell to divide to form an embryo.
These embryo cells contain the same genetic information as the adult skin cell.
When the embryo has developed into a ball of cells, it is inserted into the womb of an adult female to continue its development.
Common exam mistakes
In adult cell cloning, the nucleus comes from an adult body cell, not a gamete.
The clone is genetically identical to the adult cell nucleus donor, not the egg cell donor or surrogate.
Tissue culture and cuttings produce genetically identical plants; variation would mainly come from mutation.
Embryo transplants use cells from an early embryo before they become specialised.
Do not mix embryo transplants with adult cell cloning; the source of cells is different.