EVERYDAY SCIENCE

Detailed explanation-1: -Such environmental responses are exhibited as plasticity of growth and development, and different organs exhibit different responses to given environmental stimuli. For example, stems show negative gravitropism, whereas roots show positive gravitropism in general.

Detailed explanation-2: -Plant roots have positive gravitropism, growing towards the center of Earth. But leaves and stems do the opposite–negative gravitropism. Botanists don’t yet fully understand how plants can perceive gravity and respond to it. One of the most well-accepted theories involves the hormone known as auxin.

Detailed explanation-3: -Gravitropism ensures that roots grow into the soil and that shoots grow toward sunlight. Growth of the shoot apical tip upward is called negative gravitropism, whereas growth of the roots downward is called positive gravitropism.

Detailed explanation-4: -Charles Darwin was one of the first to scientifically document that roots show positive gravitropism and stems show negative gravitropism. That is, roots grow in the direction of gravitational pull (i.e., downward) and stems grow in the opposite direction (i.e., upwards).

Detailed explanation-5: -Plant stem grows upward opposite to the force of gravity. Hence, it exhibits negative geotropism.