Question

why seeds soaked in water swell up after some time?

Answer 1

Water enters the seeds when soaked in it for some time. This process of entry of water into the soaked seeds is called as imbibition. Thi imbibition develops large pressure called as imbibition pressure.This imbibition pressure makes the seedlings penetrate the seed coat and germinate out of it.

When seeds are soaked in water, they absorb water as a result of imbibition. They take up water and swell due to accumulation of water. Due to swelling the size of the seed increases and seed coat bursts as a result of pressure applied by swelling.

Due to imbibition pressure and accumulation of water, they swell up