NASTIC MOVEMENTS -MECHANISM

=Nastic Responses -Mechanism= Most Nastic responses are relatively fast movements, too fast to be the result of growth. They are usually a result of a change in turgor pressure. [image:http://i.imgur.com/qDkBnQB.jpg?2] Turgor pressure is the pressure within a cell usually determined by its water content, which determines its rigidity. A cell can either be turgid (rigid) or flaccid (limp / lacking rigidity). In the venus fly-trap water is forced out of the leaf cells on the surface of the leaf (making them flaccid) and is pumped into the cells on the lower side of the leaf causing them to expand (turgid). This causes the rapid movement seen.