Explanation:
In dicotyledonous plants, the sixteen-cell stage of the embryo is characterized by the formation of eight protodermal cells. The protoderm is the outermost layer of the embryo, which later develops into the epidermis of the plant. The eight protodermal cells undergo anticlinal division to give rise to the outer layer of the embryo.

Anticlinal division:
Anticlinal division is the type of cell division in which the cell divides parallel to the surface, resulting in the production of daughter cells that are perpendicular to the surface. Anticlinal divisions are responsible for the increase in the number of cell layers in the plant body. In the sixteen-cell stage of the embryo in dicots, the eight protodermal cells undergo anticlinal division to give rise to the outer layer of the embryo.

Periclinal division:
Periclinal division is the type of cell division in which the cell divides perpendicular to the surface, resulting in the production of daughter cells that are parallel to the surface. Periclinal divisions are responsible for the increase in the thickness of the plant body.

Lateral division:
Lateral division is the type of cell division in which the cell divides in a plane perpendicular to the long axis of the cell, resulting in the production of daughter cells that are also elongated. Lateral divisions are responsible for the elongation of the plant body.

Transverse division:
Transverse division is the type of cell division in which the cell divides perpendicular to the long axis of the cell, resulting in the production of daughter cells that are shorter in length. Transverse divisions are responsible for the formation of new cells in the plant body.

Therefore, in the sixteen-cell stage of the embryo in dicots, the eight protodermal cells show anticlinal division to give rise to the outer layer of the embryo.

During embryo development in dicots, the suspensor cell divided transversely a few times to produce a filamentous suspensor of 6−10 cells. The first cell of suspensor towards the micropylar end becomes swollen and functions as haustorium whereas the last cell of suspensor at the end adjacent to the embryo is known as hypophysis. The function of the suspensor is to anchor the embryo to the embryo sac and push it deep into the endosperm so that the embryo lies in a nutritionally favourable environment.