Biology 2010 JAMB Past Questions - Question 23: Which of the following stimuli is likely to elicit a nasty response in an organism?

Correct Answer

B

Explanation

Nastic or sleeping movement is a non-directional movement made by part of a stationary plant in response to diffuse or non-directional stimulus such as temperature, humidity, touch etc. The non-directional movement occurs because of changes in the turgidity of the cells. For a cell to be turgid, it must have high osmotic concentration i.e the amount of chemical or dissolved substance must be high for it to exert higher osmotic pressure on the neighbouring cells and consequently draws water from it to become turgid.