variation

• what can variation be caused by

  -mutation

  -meiosis

  -sexual reproduction
• variation can be genetic meaning what

  a difference in genotype can have affect on its phenotype
• what is most variation for the phenotype determined by

  mix of genetic and environmental factors
• what characteristics are affected by both genetic and environmental factors

  weight, hair colour, hair texture, skin colour
• what is a mutation 


  -chemical change to DNA, sequence changes -gene is altered producing genetic variant(different form of gene)

  -is inherited, occur continuously
• what happens when mutation occurs

  -most have little to no effect on protein the gene codes for

  -some change is so small the function/phenotype is unaffected

  -some may have small influence(changing eye colour slightly)

  -rarely there is a dramatic effect and genetic disorder(cystic fibrosis) is caused