I . Soak some seeds of gram (or moong in water for one day.
2. Pierce slightly big holes (2 mm diameter) at the bottom of the cup.
3. Fill it with 1cm thick layer of garden soil.
4. Sprinkle soaked seeds (moon./gram) over the soil. Water the seeds.
5. Put the cup on 2 pieces wooden or stone slabs so that there is a little gap between the top of the table and bottom of the cup.
6. Cover the lower part of the set-up with black paper.
7. water the seeds regularly with little water
8. You will observe that tire roots come out from the holes and grow towards the Earth showing positive geotropism
