1. variation
   1. same species but differene
      1. height
      2. hair
      3. shape
   2. genetic variation
      1. genes
         1. similar characteristics
         2. inherited from parents
         3. codes inside cells
            1. control make up
         4. source
            1. some mother
            2. some father
            3. combination
            4. genetic variation
            5. not gnetically identical
            6. (except identical twins)
         5. genes control
            1. plant colour
            2. eye colour
            3. blood group
            4. inherited disorder
            5. haemophilia
            6. cystic fibrosis
   3. environmental variation
      1. difference caused by conditions
         1. loosing toe
         2. suntan
         3. plant dark conditions
            1. tall
            2. spindly
            3. yellow
   4. mixture of genes & environment
      1. max height
         1. genes
         2. food in environment
2. cell
   1. nucleus
      1. chromosomes
         1. pairs
            1. mother
            2. father
            3. 23 pairs in humans
         2. carry genes
            1. characteristics
            2. eye colour
            3. hair colour
            4. height
            5. alleles
            6. different version of same gene
            7. a short length of chromosome
            8. long length of DNA
            9. coiled up
            10. arms of chromosome
            11. unique
            12. except twins
            13. DNA fingerprints from crime scenes