Cloning

Cloning

asexual reproduction
Plants can be cloned from cuttings and by tissue culture
1. Cuttings
  1. Gardeners can take cuttings from good parent plants and then plant them to produce genetically identical copies of the parent plant
    1. These plants can be produced quickly and cheaply
2. Tissue Culture
  1. This is where a few plant cells are put in a growth medium with hormones and they grow in to new plants clones of the parent
You can make animal clones using embryo transplant
1. Farmers can produce cloned offspring from their best bull or cow
2. 1. Sperm cells are taken from a prize bull and egg cells from a prize cow. The sperm are then used to artificially fertilise an egg cell. The embryo that develops is then split many times before any cells become specialised
  1. 2. These cloned embryos can then be implanted into lots of other cows where they grow into baby calves
    1. 3. Hundreds of ideal offspring can be produced every year from the best bull and cow
Adult cell cloning is another way to make a clone
1. 1. Adult cell cloning involves taking an unfertilised egg cell and removing its genetic material
  1. 2. A complete set of chromosomes from an adult body cell (e.g. skin cell) is inserted into the empty egg cell
    1. 3. The egg cell is then stimulated by an electric shock this makes it divide just like a normal embryo
      1. 4. When the embryo is a ball of cells its implanted into an adult female to grow into a genetically identical copy of the original adult body cell
Issues surrounding cloning
1. You get a reduced gene pool which means there are fewer different alleles in a population. If a population are all closely related and a new disease appears they could all be wiped out they may be no allele to give resistance
2. The study of animal clones will lead to greater development of the embryo and of ageing and age related disorders
3. Cloning could preserve endangered spedcies
4. The clones may not be as healthy
Genetic Engineering
1. Genetic engineering uses enzymes to cut an paste its genes
  1. The basic idea is to copy a useful gene from one organisms characteristic into another
  2. 1. A useful gene is cut from one organism chromosome using enzymes
    1. 2. Enzymes are then used to cut another organisms chromosome and then to insert the useful gene
      1. Scientists use this method to do all sorts of things e.g to produce insuline
2. Genes can be transferred into animals and plants
  1. Genetically modified crops have had their genes modified e.g. to make them resistant to viruses
  2. Sheep have been genetically engineered to produce substances like drugs in there milk
  3. Genetic disorders like cystic fibrosis are caused by faulty genes. Scientists are trying to insert working genes into sufferers this is called gene therapy
Pros and cons of genetic engineering
1. Pros
  1. GM crops can increase the yield of a crop making more food
  2. People living in developing nations often lack nutrients in their diets crops could be engineered to contain the nutrient that is missing
  3. GM crops are already being grown without any problems
2. Cons
  1. Some people say GM crops would affect the weeds and flowers reducing farmland boidiversity
  2. Not everyone is convinced GM crops are safe people are worried they may develop allergies to the food
  3. A big concern is that the transplanted gene may get out into the natural environment

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	Created by sian.allison over 10 years ago