Genetics and Evolution

Genes
1. Nucleus contains chromosomes
  1. Human cells has 23 pairs of chromosomes
  2. Chromosomes carry genes
    1. Gene=A shot length of the chromosome...
      1. ...which is a long length of DNA
        DNA coils up to from the arms of the chromosome
Reproduction
1. Sexual Reprodcution
  1. Genetic info from mum and dad is combined
    1. Offspring genetically different to either parent
  2. mother and father produce gametes
    1. Each has 23 chromosomes
    2. Egg and sperm fuse (fertilisation)
      1. Forms a cell with full number of chromosomes (1/2 from each parent)
2. Asexual Reproduction
  1. Ordinary Cell divides in two
    1. New cell has same genetic information
      1. Genetically Identical
      2. Clone
  2. One Parent
  3. No fusion of gametes
  4. Bacteria and Plants use it
Cloning
1. Cuttings
  1. Take cuttings from good parent plant
    1. Re-plant them
  2. Produces clones of parent plant
  3. Produced quickly and cheaply
2. Tissue Cultures
  1. plant cells put in a growth medium
    1. Grow into new plants
  2. Clones produced
  3. Made quickly with little space all year round
3. Embryo Transplants
  1. Sperm and Egg cells taken from best cow
    1. Sperm artificially fertilises egg
      1. Embryo is split
        Implanted into cows
        Give birth to cloned calves
4. Adult Cell Cloning
  1. Nucleus removed from egg and skin cell
    1. Skin cell nucleus put into empty ovum
      1. Cell given an electric shock, divides
        Embryo becomes ball of cells, implanted in surrogate mother
        Surrogate gives birth to a clone
Genetic engineering
1. Useful gene cut from chromosome using enzyme
  1. Enzyme then used to cut other organism's chromosome and insert useful gene
    1. DNA grown in bacteria
      1. Product produced from it (e.g. insulin)
Variation
1. Environmental Factors
  1. Depending on how you live your life
    1. Conditions you live in
  2. Tattoo
  3. Religion
  4. Language
  5. Scar
2. Inherited Features
  1. Comes from DNA
    1. Genes passed on in sex cells
    2. Comes from other and father
  2. Eye Colour
  3. Blood Group
  4. Gender
  5. Genetic Variation
    1. No 2 of a species are genetically identical
3. Both
  1. Weight
  2. Height
  3. Skin Colour
  4. Hair Colour
Evolution
1. Trees
  1. Species have a recent common ancestor
    1. They have similar genes
  2. Evolutionary trees show relationships between organisms
2. Darwin
  1. Natural Selection
    1. Individuals within the same species show variation because of differences within their genes
      1. Animals with the best adaptations survive and breed successfully
  2. Problems
    1. Went against religious beliefs
    2. He couldn't explain his theory
    3. There wasn't enough evidence
3. Mutation
  1. A change in an organism's DNA
  2. Can be beneficial, neutral or harmful
  3. Benficial=more likely to be passed on by natural selection
4. Lamarck
  1. Characteristics become developed during an organism's lifetime
  2. These aqiured characteristics passed onto next genration

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Genetics and Evolution

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