BIOMOLECULES AND ENZYMES

Detailed explanation-1: -Plant Tropisms A tropism is a turning toward or away from a stimulus in the environment. Growing toward gravity is called geotropism. Plants also exhibit phototropism, or growing toward a light source. This response is controlled by a plant growth hormone called auxin.

Detailed explanation-2: -Gravitropism is a plant’s movement in response to gravity. It causes roots to grow down and the shoots to grow up towards the sky.

Detailed explanation-3: -Soil contains minerals such as nitrogen, phosphorous and potassium that are essential for plants. Soil also holds water which is used by plants. The air present in the soil helps roots breathe.

Detailed explanation-4: -Gravity affects the ecology and evolution of every living organism. In plants, the general response to gravity is well known: their roots respond positively, growing down, into the soil, and their stems respond negatively, growing upward, to reach the sunlight.