Which of the following is/are incorrect about nastic movement? P. It is a paratonic movement. Q. It occurs due to change in turgor pressure as well as differential growth. R. Nyctinasty is an example of nastic movement. S. It is induced by endogenous stimulus.

Nastic movements are non-directional responses to stimuli (paratonic). P is correct. Q is correct because both turgor changes AND differential growth can cause nastic movements. R is correct - nyctinasty (sleep movements) is nastic. S is INCORRECT because nastic movements are induced by external (exogenous) stimuli like light, touch, or temperature, not endogenous ones. Therefore S is the only incorrect statement.