The area of response in phototropism and geotropism is

The area of the plant which perceives a stimulus is called as perceptive region. The area of the plant which shows the response is called as responsive region. Tip or apex of the shoot is the perceptive region for the light. It is the site which receives the phototropic stimulus and shows corresponding response. The responsive region is the region of elongation. Due to phototropism and geotropism, more growth is seen on the shaded side or upper side than illuminated side or lower side. This results in elongation of root and stem.