HORTICULTURE

Detailed explanation-1: -The effect of light on plant growth is called phototropism. The effect of gravity on the direction of plant growth is called gravitropism. (The effect of gravity on plant growth is often called geotropism because the Earth itself (geo) is responsible for the stimulus.

Detailed explanation-2: -Roots of a plant demonstrate positive gravitropism and grow toward the source of gravity detected by the statocytes in root caps.

Detailed explanation-3: -The growth of a plant toward light is called phototropism. Stems and leaves grow toward the light to obtain more light for photosynthesis. Gravitropism is plant growth in response to gravity. This can be seen in how roots grow downward and stems develop upward.

Detailed explanation-4: -Plants’ growth response to gravity is known as gravitropism; the growth response to light is phototropism. Both tropisms are controlled by plant growth hormones.

Detailed explanation-5: -Stems are positively phototropic, and roots are typically negatively phototropic. Gravitropism is directional growth in response to gravity. Stems are negatively gravitropic, and roots are positively gravitropic. The adaptive value of these tropisms is clear.