Experiment to demonstrate phototropism/effect of unidirectional light on the growth of shoot

1. Select two potted seedlings of bean of equal age and size and water them.
2. Place one of the seedlings in a box painted black on each side. The box should have a hole on one side to allow in light.
3. Subject the second seedling to the same conditions as the first one except that the pot is mounted on a slowly rotating clinostat.
4. Leave the experiment to stand for 3 days

Note that each seedling should be growing straight at the beginning of the experiment.

  Observation The seedlings on the clinostat grew straight while the other bent toward the light NB. Slowly rotating clinostat ensures uniform exposure of the shoot from all directions. The significance of phototropism, allow the shoot to grow towards and receive light for photosynthesis. Importance of phototropism Positive phototropism causes the stems of plants to grow towards a light source causing the leaves of the plant to be pointing towards the light source; this allows the leaves to absorb more light which maximizes photosynthesis. Please find free downloadable notes, exams and marking guides of agriculture, biology, Physics, chemistry etc.  from digitalteachers.co.ug website. Dr. Bbosa Science