Cloning

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 Vegetative Propagation

• Taking cuttings
• Grafting

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.

Artificial Cloning

• 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.

Non-Reproductive Cloning

• 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.