Cloning

- Tissue Cultures - a few plant cells are put into a growth medium with hormones and they grow into a new plant, which are clones of the parent plant - the plants can be made very quickly, in restricted space and can be grown all year round - the process is used by scientists to preserve rare plants that are hard to reproduce naturally - also used by plant nurseries to produce lots of stock quickly

- Cuttings - gardeners can take cuttings from good parent plants, and then plant them to produce genetically identical copies of the parent plant - cuttings are taken, each with a new bud on - the cuttings are kept in moist conditions until they are ready to plant - plants can be produced quickly and cheaply - it is an older and simpler method

- Sperm cells are taken from a prize bull and egg cells are taken from a prize cow - the sperm are then used to artificially fertilise the egg cell - the embryo that develops is then split many times to form clones before any cells can become specialised

- The cloned embryos can then be implanted into lots of other cows where they grow into baby calves, which will all be genetically identical

- Hundreds of ideal offspring can be produced every year from the best bull and cow

- This process is the same for cloning any animal via embryo transplant

- Involves taking an unfertilised egg cell and removing its nucleus

- The nucelus is then removed from an adult body cell and is implanted into the 'empty' egg cell

- The egg cell is then stimulated by an electric shock, which makes it divide like a normal embryo

- When the embryo is a ball of cells, it is implanted into the womb of an adult female - it grows into a genetically identica; copy of the original adult body cell as it has the same genetic information

- This was the technique used to create Dolly - the famous cloned sheep

- The process can reduce the gene pool (smaller variation of alleles in the population) - if the population are all closely related and if a new disease appears, they could all be wiped out as there may be no allele in the population that gives resistance

- Study of animal clones could lead to greater understanding of the development of the embryo and  of ageing and age-related disorders

- Could be used to preserve endangered species

- It is possible that cloned animals might not be as healthy as normal ones

- SOme worry that humans might be cloned in the future - if it was allowed, any success may follow many unsuccessful attempts