Explain how soaked seeds swell up and burst their seed coats.

When dried seeds are soaked in water after a few hours they are seen to swell up this is because the concentration of the seed content is much higher than the concentration of the water thus endosmosis occurs. If these swollen seeds are left in water the seeds take up more and more water due to which turgor pressure increases. When the turgor pressure exceeds the wall pressure due to excessive endosmosis of water the seed coat bursts open.