Effect of environment on the expression of phenotype


  • Environmental factors can affect the expression of genes of an organism eg nutrients, temperature, exposure to the sun, acidity.
  • Environmental factors can change the phenotype without changing the genotype eg human skin colour is affected by UV radiation (gets darker). Light can also change leaf colour in plant from yellow to green.
  • Some alleles produce temperature sensitive enzymes that work only in certain temperatures. eg the himalayan fur pattern in rabbits, the enzyme functions at low temperatures so cooler areas of nose, tail, feet are black.
  • Genotype + environment = phenotype.
  • Changes in phenotype caused solely by environment factors are not inherited by the next generation.
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