NEET BIOLOGY

Detailed explanation-1: -Many petals of flowers open in the daylight and closed in the evening in response to the intensity of light. This is a growth movement in plants and an example of Photonastic movement. Examples are: Dandelion flower, Moonflower, flower of Cestrum Nocturnum etc.

Detailed explanation-2: -The non-directional movement of petals of flowers in response to light is called photonasty. For example, a dandelion flower opens in the morning due to bright light and closes in the evening when the light fades.

Detailed explanation-3: -The non-directional movement of the plant in response to the light is known as photonasty. 2. Example: The closing of moonflower petals in response to light . 1. The non-directional movement of the plant in response to the touch of an object is known as thigmonasty.

Detailed explanation-4: -Photonasty is nastic movement shown by the plant in response to light. Hydronasty is nastic movement shown by the plant in response to water current. Thigmonasty is nastic movement shown by the plant in response to touch or vibration.