Clones in Nature
Clone: a GENETICALLY identical individual
Vegetative Propagation: the production of structures in an organism that can grow into new individual organisms. These offspring are genetically idententical to the parent.
Advantages of Asexual Reproduction
- Quick, allows organisms to reproduce rapidly.
- Can be completed when sexual reproduction is not possible.
- All offspring have the genetic information to enable them to survive in their environment.
Disadvantages of Asexual Reproduction
- Does not product any genetic variety, so any genetic parental weaknesses are passed on to the offspring.
Artificial Clones in Agriculture
Artificial Vegetative Propagation
- Taking cuttings
Artificial Propagation Using Tissue Culture
- Micropropagation by Callus Tissue Culture
- Small piece of tissue, usually from shoot tip. Called an Explant.
- Explant placed on nutrient growth, forming a mass of undifferentiated cells called a callus.
- Single callus cells are removed and placed on shoot-stimulating hormones.
- The growing shoots are moved onto root-stimulating hormones.
- growing plants are them acclimatised in a greenhouse before being moved outside.
- Splitting Embryos
- Cells developing from an embryo are separated out, each developing a genetically identical organism.
- Nuclear Transfer
- Mamary cell and an enucleate (without nucleus) egg cell are fused by electro-fusion.
- reconstructed cell is implanted into surrogate uterus.
- Therapeutic Cloning
- If cells are genetically identical to the individuals own, they will not be rejected by the immune system.
- Cell culture of organs cuold mean an end for waiting lists for organs.
- Cloned cells can be used to generate any type of cell because they are totipotent.