Question

How does prototropisms occur?

Answer 1

The growth movement in plants in response to light stimulus is known as phototropism.The shoots show positive phototropism and the roots show negative phototropism. This means that the shoots bend towards the source of light whereas the roots bend away from the light source.

example:-

The flower head of sunflower is positively phototropic and hence it moves from east to west along with the sun.

Answer 2

Environmental triggers such as light will change the directions that plant parts grow in. These directional, or tropic, movements can be either towards the stimulus, or away from it. So, in two different kinds of phototropic movement, shoots respond by bending towards light while roots respond by bending away from it.