Separation of Substances — Science STD 6 — Question

The grains are separated from stalks (on which they grow) by the process of threshing. In this process stalks (of wheat, paddy, etc) are beaten to separate grains from the bundle of stalks.
Note: This method is based on the fact that the stalks (or stems) of the crop plant are soft material whereas the grains themselves are very hard. Being soft, stalks can be broken into pieces on beating but the grains remains unaffected.