 Genetic processes work in combination with an organism 's environment and experiences to influence development and behavior , often referred to as nature versus nurture . The intra- or extra @-@ cellular environment of a cell or organism may switch gene transcription on or off . A classic example is two seeds of genetically identical corn , one placed in a temperate climate and one in an arid climate . While the average height of the two corn stalks may be genetically determined to be equal , the one in the arid climate only grows to half the height of the one in the temperate climate due to lack of water and nutrients in its environment . 
