A hydrangea plant has blue flowers when grown in acidic soil, but has pink flowers when grown in basic soil. A clone of the pink-flowered plant is grown in acidic soil and produces blue flowers. This change in flower color is most likely due to
Environmental Factors affecting gene expression. The differences in acidity level in the soil causes the gene to be expressed as either pink flowers (basic soil) or blue flowers(acidic soil). I hope this helps!