NEET BIOLOGY

Detailed explanation-1: -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.

Detailed explanation-2: -Geotropism is a type of tropism where plants show some growth in response to gravity. Roots growing downwards is an example of geotropism.

Detailed explanation-3: -Graviperception by plant roots is believed to occur via the sedimentation of amyloplasts in columella cells of the root cap. This physical stimulus results in an accumulation of calcium on the lower side of the cap, which in turn induces gravicurvature.

Detailed explanation-4: -Gravitropism, also called geotropism, where geo-means the earth, and tropism refers to turning, is the growth of a plant’s organ or change in the direction of its growth in response to gravity.