Evolution%20and%20Genes

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Evolution and Genes
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Evolution

• Evolution is the sum of all transformations
  undergone by a particular primitive life form
  over time

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Natural Selection

• Natural Selection is a theory developed by the
  scientist Charles Darwin to explain the evolution
  of species
• In this theory individuals whose physical and
  behavioural characteristics are best adapted to
  their habitat have a better chance of reproducing
  and passing on their characteristics

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Genetic Mutation

• The nucleus of the cell contains the chromosomes
  that have the genes for that species
• A gene can become mutated so that it is different
  from the normal form
• Individuals who carry a beneficial mutation have
  a better chance of survival and therefore a
  better chance of passing on that gene through
  reproduction

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Genes

• Genes carry instructions that produce a
  characteristic
• A characteristic is a physical, or non-physical
  property that can vary from one individual to
  another within the same species
• Each characteristic needs at least 2
  instructions, called alleles

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• Together all of our genes make up our genetic
  code or DNA
• An individual gets his or her genetic code from
  his/her parents
• Half of the code comes from Mom and the other
  half from Dad
• Mom gives 1 allele for eye colour, Dad gives one
  allele for eye colour, 2 alleles genetic code
  for eye colour

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Dominant vs Recessive

• An allele (variation) for a gene can be either
  dominant or recessive
• Dominant alleles will be displayed, which means
  if you get even one of these alleles form a
  parent you WILL have that trait
• Recessive alleles will only be displayed if you
  get two (one recessive from mom AND one recessive
  from dad)