6.2.1

• natural clones in plants

  produced via asexual reproduction via mitosis from the meristem
• examples of natural plant clones

  runners - above ground

  rhizome - below ground
• advantages of plants natural clones

  free

  fast

  able to selected plants with desirable traits to produce them
• artificial clones in plants

  plant cutting

  micropropagation
• plant cutting

  the cutting of a non flowering stem and replanting it in soil
• micropropagation

  sterilised plant tissue culture is grown on agar then planted into soil
• advantages of micropropagation

  fast

  disease free

  clone genetically modified plants

  clone seedless plants

  clone endangered plants

  clone plants that do not grow easily
• disadvantages of micropropagation

  expensive

  labour intense

  the plants have no immunity

  promotes monoculture

  reduces gene pool

  no variation or natural selection of species
• in vivo

  in body
• in vitro

  in glass
• examples of natural clones in animals

  limb regeneration

  monozygotic twins ( zygote division )

  mitosis of cells

  parthenogenesis
• why are artificial clones of animals made

  they are used in farming to maintain desirable characteristics
• ways to make an artificial animal clone

  embryo splitting

  somatic cell nuclear transfer ( SCNT )
• embryo splitting

  egg and sperm are taken and fertilised in vitro

  when the embryo forms it is split into single cells which are inserted into different host mothers

  this creates identical offspring NOT clones of the parents
• somatic cell nuclear transfer

  somatic cell and egg cell are taken

  egg cell has nucleus removed

  nucleus from somatic cell is inserted into egg cell

  electrical current is applied to embryo

  embryo cell is split into individual cells and inserted into host mother

  this creates clones of the somatic cell organism AND identical offspring
• problems with SCNT

  shorter life due to aged DNA

  not efficient

  increased miscarriage rate
• advantages of SCNT

  genetically modified embryos can be clones

  clones of a specific animal

  clones of an endangered animal

  clones with the desired trait can pass it to offspring