variation

• characteristics are caused by:

  • inherited genes
  • the environment you have developed in
  • combination of both
• phenotype

  the physical appearance of the trait

  • dominant

  shown with capital letters

  masks the other trait

  • recessive

  shown with lowercase letters

  only shows if two traits are recessive
• genotype

  pair of alleles for a gene

  • homozygous

  two identical versions of a gene present

  eg. RR

  • heterozygous

  two different versions of a gene

  both dominant and recessive trait

  eg. Rr