Cloning

• Cloning


  The process of creating genetically identical copies of an organism
• Plants can be cloned by

  • Tissue culture
  • Cuttings
• Tissue culture


  1. Plant cells are put in a growth medium with hormones

  2. They grow into new plants-clones of the parent plant
• Tissue culture


  • Plants can be made very quickly, in very little space, and be grown all year
  • Used by scientists to preserve rare plants that are hard to reproduce naturally and by plant nurseries to produce lots of stock quickly
• Cuttings


  1. Gardeners take cuttings from good parent plants

  2. They plant the cuttings to produce genetically identical copies (clones) of the parent plant
• Cuttings


  • Produces plants quickly and cheaply
  • Older, simpler method than tissue culture
• Animal cloning using embryo transplants

  1. Sperm cells taken from a prize bull

  2. Egg cells taken from a prize cow

  3. Sperm used to artificially fertilise egg cell

  4. Embryo that develops is split many times to form clones before cells become specialised

  5. Cloned embryos implanted into other cows to grow into baby calves
• Animal cloning using embryo transplants


  • Produces hundreds of "ideal" offspring every year from the best bull and cow
• Adult cell cloning


  1. Unfertilised egg cell has its nucleus removed

  2. Nucleus from adult body cell inserted into 'empty' egg cell

  3. Egg cell stimulated by electric shock to divide like a normal embryo

  4. Embryo implanted into womb of adult female to grow into clone of original adult body cell
• Adult cell cloning


  • Used to create Dolly the famous cloned sheep
• Cloning quickly gets you lots of "ideal" offspring but also reduces the gene pool, which could make a population vulnerable to new diseases
• Studying animal clones could lead to greater understanding of embryo development, ageing and age-related disorders
• Cloning could be used to help preserve endangered species
• Cloned animals might not be as healthy as normal ones, e.g. Dolly the sheep had arthritis
• If human cloning was allowed, any success may follow many unsuccessful attempts, e.g. children born severely disabled