This outer layer is termed the protoderm and will give rise to the epidermis of the plant. A lens shaped cell derived from the upper portion of the suspensor cell file and shown dark coloured, divides to give rise to the central cells of the root apex. This is the first appearance of bilateral symmetry. After seed dispersal and germination, development of the embryo is reactivated. Adult plant growth is due to the activity of meristems established during embryogenesis.
Meristems are organised cellular structures capable of indeterminate growth.
The embryo contains root and shoot apical meristems. Cell division is precisely choreographed during Arabidopsis embryogenesis. Or are cell fates primarily determined by developmental cues from surrounding cells. Genetic screening of Arabidopsis plants for developmental defects. In either case, the mutant gene can be isolated and characterised - to gain a more direct view of the mechanisms of development.