Question

Design an experiment to demonstrate hydrotropism.

Answer 1

Hint: Living organisms are very much conscious of their surroundings and need several physical factors for their proper growth and survival. For every organism to grow well, it needs water, air, temperature at an optimum level.

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

Hydrotropism is defined as the type of tropism which is featured by growth and movement of the plants towards or away from the water sources or moisture. It is an involuntary reaction of the plants to grow towards water.
Plants observe water in their surroundings so that they can absorb water for various metabolic activities. The water molecules are reacted and absorbed by the plants through their root systems. The plant roots have capacity 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 is the place from where the plants absorb the water. Hydrotropism is necessary for plants as it helps the plants to identify water sources under the ground. The process of hydrotropism can be observed with the help of a simple experiment. The experiment will help to understand the whole process of plant movement that occurs in presence of any water source.

For the experiment, we will need to have two beakers, soil, plant seeds and water.
First of all, we have to take moist soil in beaker 1 and in this we will slow and grow the seeds. In the second beaker, one-part dry soil is taken and another part moist soil is added and seeds are sown in this. Also, we need to put a small beaker of water, keeping it adjacent to the seeds. The setup is left untouched for some days so that the plants can grow from the seeds.
After a few days, it is seen 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 seen to grow towards the water source that was kept towards the plants.
Roots will be curved or moved sideways to grow towards the water source and this condition of the response of the plants towards water is known as hydrotropism.

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