DENDROLOGY

Detailed explanation-1: -The process of growth of roots towards water in known as positive hydrotrophism.

Detailed explanation-2: -The survival of terrestrial plants depends upon the capacity of roots to obtain water and nutrients from the soil. Directed growth of roots in relation to a gradient in moisture is called hydrotropism and begins in the root cap with the sensing of the moisture gradient.

Detailed explanation-3: -1. Movement of plants in response to water is called hydrotropism. In this case, water is a stimulus to which the plant can show two responses. 2. It can move towards the water source-Positive hydrotropism.

Detailed explanation-4: -The orientation of the plant in response towards light is called Phototropism. So, the correct option is ‘Phototropism. ‘