cloning

cloning is the process of producing genetically idnetical cellls or organims from the cells of an exsisting organism

Reprod uctive

It is used to make a complete organism that is genetically identical to another organism. It can be used to save endangered animals or increase the number of organisms with desired characterisitcs.

Non reproductive

it is used to make embryoinv stem cells that are genetically identical to another organism also known as therapeutic cloning. Stem cells have the potential to become any type of cell.

Nucleur transfer

• a body cell is taken from sheep A. The nucleus is extracted and kept.
• an egg  cell is taken from sheep B. It's nucleus is removed to form and enucleuated egg cell
• the nucleus from sheep A is inserted into the enucleated egg cell- the egg cell from sheep B now contains the genetic information form sheep A
• the egg cell is stimulated to divide and an embryo is formed
• in reproductive cloning the embryo is implanted into a surrogate mother. A lamb is produced that's a genetically identical copy of sheep A.
• In non reproductive cloning stem cells are harvested from the embryo. The stem cells are genetically identical to the cells in sheep A.

Pros

• desireable genetic characteristics are always passed on
• infertile animals can be reproduced
• cloning can happen at any time - do not have to wait for breeding season

Cons

• undesirable traits are also passed on
• it is very time consuming and expensive

• cells are taken from the original plant that's going to be cloned. Cells from the sten and root tip are used because they're stem cells - like in humans, plant stem cells can develop into any type of cell
• the cells are sterilised to kill any microorganisms- bacteria and fungi compete for nutrients with the plant cells, which decreases their growth rate
• the cells are placed on a culture medium containing organic nutrients, this is carried out under aseptic techniques. The cells divide to produce a mass of undifferentiated cells. The mass can be subdivided to produce lots of plants very quickly.
• When the cells have divided and grown into a small plant they're taken out of the medium and planted in soil- they'll develop into plants that are genetically identical to the original plant

• cells are taken from the original plant that's going to be cloned. Cells from the sten and root tip are used because they're stem cells - like in humans, plant stem cells can develop into any type of cell
• the cells are sterilised to kill any microorganisms- bacteria and fungi compete for nutrients with the plant cells, which decreases their growth rate
• the cells are placed on a culture medium containing organic nutrients, this is carried out under aseptic techniques. The cells divide to produce a mass of undifferentiated cells. The mass can be subdivided to produce lots of plants very quickly.
• When the cells have divided and grown into a small plant they're taken out of the medium and planted in soil- they'll develop into plants that are genetically identical to the original plant

Micropropogation is when tissue culture is used to produce lots of cloned plants very quickly. Cells are taken fromdeveloping cloned plants and subcultered- repeating this process creates large numbers of clones.

it is the natural production of plant clones from non reproductive tissues e.g. roots, leaves and stems.

Elm trees produce clones from structures called suckers. A sucker is a shoot that grows from shallow roots of an elm tree. Suckers grow from sucker buds (undeveloped shoots) that are scattered around the tree's root system. The buds are normally dormant. During times of stres or when a tree is dying, the buds are activated and suckers begin to form. Suckers can pop up many meters away from the parent tree, which can help to avoid the stress that triggered their growth. They eventually form completely seperate trees.

Advanatges

• desireable genetic characteristics are always passed on to clones. This doesnt always happen when plants reproduce sexually
• plants can be reproduced in any season because tissue culture us carried out infoors
• sterile plants can be reproduced
• plants that take a long time to produce seeds can be reproduced quickly.

Disadvantages

• Undesireable genetic characteristics are always passed on to clones
• cloned plant populatiobs have no genetic variability, so a single disease could kill them all
• production costs are very high due to high energy use and the training of skilled workers.