Question
Describe two types of tropic movements in plants.
Answer
Here are two types of tropic movements in plants:
Phototropism is the directional growth of a plant part in response to light. The shoots of plants grow towards the light, while the roots grow away from the light. This is because of a hormone called auxin, which is produced in the tips of the shoots. Auxin accumulates on the side of the shoot that is shaded, causing the cells on that side to grow faster. This causes the shoot to bend towards the light.
Geotropism is the directional growth of a plant part in response to gravity. The roots of plants grow downwards, while the shoots grow upwards. This is because of a hormone called auxin, which is produced in the tips of the shoots and roots. Auxin accumulates on the side of the roots that is facing down, causing the cells on that side to grow faster. This causes the roots to bend downwards.