CloningSpec 4.6.2.5
In short
Cloning produces genetically identical plants or animals. Plants can be cloned by tissue culture or cuttings, and animals by embryo transplants or adult cell cloning. In adult cell cloning, the nucleus is removed from an unfertilised egg cell and replaced with an adult body cell's nucleus. An electric shock then stimulates the egg cell to divide to form an embryo.
| Method | What happens | Used for |
|---|---|---|
| Tissue culture | Small groups of cells from part of a plant are used to grow identical new plants | Preserving rare plant species; commercially in nurseries |
| Cuttings | An older, but simple, method: a piece of the parent plant is used to grow a new plant | Gardeners producing many identical new plants from a parent plant |
| Embryo transplants | Cells from a developing animal embryo are split apart before they become specialised, then the identical embryos are transplanted into host mothers | Producing several identical animals |
| Adult cell cloning | See the steps below | Producing an animal with the same genes as an adult |
Adult cell cloning
- 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.
Benefits, risks and objections
| Potential benefits | Potential risks and objections |
|---|---|
| Many identical copies of plants or animals with a useful characteristic can be produced | Clones have the same genes, so there is less genetic variation and a single disease could affect them all |
| Rare plant species can be preserved | Some people have ethical objections to cloning animals |
| Plants can be produced quickly and cheaply, all with the desired characteristic | Cloned animals may be less healthy than normally produced animals |
Adult cell cloning: the nucleus comes from the adult body cell, and the egg cell has its own nucleus removed. If you mix these up you lose the marks.
Quick check
Give the three possible causes of variation.
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Genetic causes, environmental causes, or a combination of genes and the environment.
What do all variants arise from?
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Mutations.
When have two populations become two new species?
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When they are so different in phenotype that they can no longer interbreed to produce fertile offspring.
Name one problem caused by selective breeding.
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Inbreeding, where some breeds are prone to disease or inherited defects.
What is a GM crop?
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A crop that has had its genes modified by genetic engineering.
Written and checked against the AQA GCSE Biology (8461) specification · Updated October 2026