Question

Describe the three-bean seeds experiment.

Answer 1

Objective: To show that water, temperature, and oxygen are essential for germination. (Three-Bean Seeds Experiment)

Apparatus required: Beaker, bean seeds (3), wooden piece, or a glass slide, water

Method:

1. The air-dried seeds are attached to a piece of wood, one at each end and one in the middle.
2. This is then placed in a beaker, and water is poured into it until the middle seed is half-immersed in it.
3. The beaker is then left in a warm place for a couple of days.
4. From time to time, water is added to maintain the original level.

Observation:

1. After a couple of days, it is observed that the bean seed half-immersed in water germinates normally because it has sufficient water, oxygen, and temperature.
2. The bottom seed has sufficient moisture and temperature but no oxygen, therefore it may put out only a radicle, its further growth is checked for want of oxygen.
3. The upper seed got only air and temperature and thus fails to germinate in the absence of water.

Conclusion:

1. This experiment shows that seeds germinate only if all the three factors, i.e., water, oxygen, and suitable temperature, are available.
2. In the absence of any one of these three factors, germination will not take place.