What is the difference between etiolation and phototropism?
Etiolation is the long, pale growth of a plant caused by lack of light. This link might help you. http://home.comcast.net/~john.kimball1/B… Phototropism is the response of a plant to grow towards light. All plants have positive phototropism in their leaves and flowers which mean they grow towards light. Many roots have negative phototropism which causes them to grow away from light. Phototropism is enabled by auxins. Auxins are plant hormones that have many functions. In this respect, auxins are responsible for expelling protons (by activating proton pumps) which decreases pH in the cells on the dark side of the plant. This acidification of the cell wall region activates enzymes known as expansins which break bonds in the cell wall structure, making the cell walls less rigid. In addition, the acidic environment causes disruption of hydrogen bonds in the cellulose that makes up the cell
