AP BIOLOGY

Detailed explanation-1: -Some common plant stimuli include light, gravity, water, movement of the sun, and touch. The naming of the tropism is associated with the stimulus. For example, the movement of plant roots towards water is called hydrotropism.

Detailed explanation-2: -A chick hatching out of an egg is a natural phenomenon of reproduction in hens. It requires a particular time period and temperature to occur. Hence it is not a response to stimuli.

Detailed explanation-3: -Plants respond to various stimuli. Response to environmental stimuli is known as tropism and the stimuli may be light, water, gravity, etc. Various types of tropism are: Phototropism: Movement or growth of plants towards light is called phototropism.