After reaching the fertile soil, the seeds absorb water and swell up. Now the embryo
begins to germinate and its radical (root sprout) grows down into the soil and forms a root. The plumule grows upward in the air and develops leaves and shoot. It is a form of young small plant.
Essential conditions for germination:
All seeds need (i) water, (ii) oxygen (air) and (iii) proper temperature for germination. Some seeds also need the right amount of light. When the seed finds the right conditions, it activates and germinates the enzyme by moving water and oxygen inward from the outer layer and forms the seed root which receives water from the ground and forms a stem which moves towards the wind and leaves come out on the trunk from which the sun makes food in the light.
