What Is Gravitropism?
Gravitropism, also known as geotropism, is the process of a plant's directional growth in response to the force of gravity. It is a fundamental mechanism that ensures a plant is correctly oriented for survival, with its roots growing down into the soil and its shoots growing up towards the light.
Section 2: Positive and Negative Gravitropism
Gravitropism is categorized into two types. Positive gravitropism is growth towards the gravitational pull, which is exhibited by plant roots. This helps anchor the plant and absorb water and nutrients from the soil. Negative gravitropism is growth away from the gravitational pull, as seen in plant stems and shoots. This response helps position the leaves to receive maximum sunlight for photosynthesis.
Section 3: A Practical Example
A simple way to observe gravitropism is to take a small potted plant and lay it on its side. After a few days, you will notice that the stem has started to bend and grow upwards, away from the pull of gravity (negative gravitropism). If you could see the roots, you would find they have reoriented to grow downwards (positive gravitropism).
Section 4: Why Is Gravitropism Important?
Gravitropism is crucial for a plant's survival from the moment a seed germinates. It guarantees that regardless of a seed's orientation in the soil, its roots will grow down to find stability and resources, while its shoot will grow up to emerge from the soil and access sunlight. This fundamental response ensures the plant establishes itself correctly in its environment.