The fruit wall called the pericarp protects the seeds.
The seed absorbs water through the micropyle. The cotyledons swell and rupture the testa.
rupture
When there is water, the enzymes in the cotyledons become active.
Amylase breaks down the stored starch to maltose
And proteases break down the protein molecules to amino acids.
Maltose and amino acids diffuse to the embryo. They are used to from new cells.