reproductive cloning =>production of a new individual with the same genotype of an existing one

non-reproductive cloning => supplies replacement cells whose genotype matches that of an existing organism

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  • Created by: kim
  • Created on: 03-02-11 19:21

describe the production of natural clones in plant

clones => whole organism which carries identical genetic material because they are derived from the same original DNA

examples of natural cloning => identical twins, plants reproducing asexually, bacteria dividing by binary fission.

vegetative propagation =>production of structures in an organism that can grow into new organisms. contain same genetic information as the parent therefore clones of parents. form of natural cloning

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natural vegetative propagation in elm tree

  • elm tree are adapted to reproduce asexually following damage to parent plant
  • allows species to survive catastrophes i.e. burning or disease
  • new growth in the form of root suckers appear within 2 months after destruction of main trunk
  • suckers grow from meristem tissue in trunk close to the ground since where least damage is likely to occur.
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  • root suckers help the elm spread because they can grown round the original trunk
  • when tree is stressed (felled during the coppice cycle) suckers grow into a circle of new elms called clonal patch
  • clonal patching puts out new suckers so that the patch keeps expanding as far the resources permit


  • when new trees get to 10cm in diameter they become infected and die
  • new trunks are clones of old ones so they have any resistance to the fungal attack therefore remain vulnerable
  • no genetic variation within cloned population so natural selection cant occur
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describe the production of artificial clones of pl

tissue culture => separation of cells of any tissue type and their growth in or on a nutrient medium

artficial propagation using tissue culture (micropropagation)

used for plants that:

  • are difficult to grow from seed
  • don't have a natural method of asexual reproduction
  • are desirable hybrids and don't breed true
  • have been genetically engineered
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process of micropropagation

  • explant is taken
  • placed on a nutrient medium containing amino acids and vitamins, inorganic ions and plant hormones to stimulate mitosis
  • cells in tissue divide but don't differentiate hence forming a callus
  • after a few weeks, singles callus cells are removed and placed into a growing medium containing plant hormones to encourage shoot growth
  • after a further few weeks, growing shoots are transferred to a different growing medium with different hormone concentrations to encourage root growth
  • growing plants are transferred to a greenhouse to become acclimatised and grown further before they are planted outside.
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discuss the advantages and disadvantages of plant


  • many genetically identical plants can be produced from one original plant
  • plants can be produced at any time of the year and air-freighted around the world
  • callus can be genetically engineered


  • plants are genetically identical so they are susceptible to a newly mutated pathogen, pest or change to an environment
  • process is labour-intensive
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describe how artificial clones of animals can be p

produced in two ways

division of early embryos where at this stage all cells differentiate into any tissue. relatively common in selective breeding of a cattle to superovulate a female with desired traits. eggs are fertlised in vivo or in vitro with sperm from a suitable male then subdivide the embryos. embryos implanted into surrogate mothers. desirable female is not put into risk at pregnancy and available for further superovulations and increases stock of selectively bred animals.

transfer of nucleus from a cell into an egg cell without the nucleus (enucleated cell) => somatic nuclear transfer. egg goes through stages of development using genetic information from the inserted nucleus.

uses of nuclear transfer

  • breeding endangered species
  • produce transgenic animals for 'pharming' human chemicals
  • produce embryonic cells that are almost genetically identical with the donor of the nucleus
  • produce largely human cells for research into various diseases
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discuss the advantages and disadvantages of clonin


  • reproductive rate of a genetically superior animal is increased
  • number of animals with a wanted trait is increased
  • cloned embryo can be tested for certain genetic diseases before implantation into a surrogate
  • a fertile female of an endangered species is not needed for somatic nuclear transfer


ethical objections; animals concerned are not only being denied their natural instincts and behaviour but are being used by the breeder as a means to an end.

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