Question

What is hydrotropism? Describe an activity to demonstrate hydrotropism.

Answer 1

Hint:
Living organisms are sensitive to their surroundings and need several physical factors for their proper growth and survival. For any organism to grow well, it requires water, air, temperature at an optimum level.

Complete answer:
The organism reacts to the different types of stimulus that they receive from their surroundings. The response of the organisms or any movement or growth due to the stimulus are referred to as tropism. Tropism can be defined as the orientation response towards any type of stimulus. The type of response that the organism exhibits towards any type of tropism is mainly involuntary in nature, which means the organism can go either towards or move away from the response.

Hydrotropism is known as the type of tropism which is characterised by growth and movement of the plants towards or away from the water sources or moisture. It is an involuntary response of the plants to grow towards water.

Plants recognize water in their surroundings so that they can absorb water for various metabolic activities. The water molecules are sensed and absorbed by the plants through their root systems. The plant roots are able to sense the presence of water molecules and they further send signals to the tip of the elongated part of the root. The root tip are the areas from where the plants absorb the water. Hydrotropism is essential for plants as it helps the plants to identify water sources under the ground.

The process of hydrotropism can be demonstrated with the help of a simple experiment. The experiment will help to understand the process of plant movement in presence of any water source. For the experiment, we need two beakers, soil, plant seeds and water.

First of all, we have to put moist soil in beaker1 and in this we will sow the seeds. In the second beaker, one part dry soil is added and another part moist soil is added and seeds are sown in this. Also, we have to add a small beaker of water, keeping it adjacent to the seeds. The setup is left for some days so that the plants can grow from the seeds.

After some days, it is observed that in beaker 1 the plants will grow normally with straight roots due to the presence of moisture in the soil. In the second beaker, the plants were observed to grow towards the water source that was kept near the plants. Roots will be curved or moved sideways to reach the water source and this condition of the response of the plants towards water is called hydrotropism.

Note: The plants require water to carry out various processes and they have the tendency to move towards water sources. This characteristic of the plants to grow towards water is known as hydrotropism.