Developmental steps in the formation of a plant embryo

(a) The two-cell stage consists of the apical cell and basal cell. (b) The eight-cell stage consists of a pro-embryo and a suspensor. The suspensor gives rise to extra embryonic tissue that is needed for seed formation. (c) At the heart stage, all the plant tissues have begun to form. Note that the shoot meristem is located between the future cotyledons, while the root meristem is on the opposite side. (d) A seedling showing basal, central, and apical regions. The inset shows the organization of the shoot meristem. Note: The steps shown in parts (a), (b), and (c) occur during seed formation, and the embryo would be enclosed within a seed.