Control and Coordination — Question 5

Growth movement of the roots of the plant towards water is called hydrotropism.

Below experiment demonstrates hydrotropism:

Procedure

1. Take two beakers 1 and 2.
2. In beaker 1 add moist soil and sow the seeds.
3. In beaker 2 add dry soil in one part and moist soil in another part and sow the seeds. Also, place a small porous pot containing water in the dry part adjacent to the seedling.
4. Leave the set up for few days so that the plant can grow.

Observation

1. In beaker 1, the plant grows normally and the roots are straight.
2. In beaker 2, the roots bend towards the source of water and do not grow straight.

Conclusion

This experiment confirms that roots of a plant show positive hydrotropism as they bend towards the source of water (porous pot).