In dicots the zygote elongates and then dividual by a transverse wall into two unequal cells i.e. basal suspensor cell and terminal embryo cell.
The suspensor cell divides transversely a few times to form a 6-10 celled suspensor .The suspensor helps in pushing the embryo in the endosperm .
The upper most cell of the suspensor towards the micropylar end forms haustorial cell while the lowermost cell of the suspensor towards the termimal cell is called hypophysis .
The haustorical cell function as hausforium and the hypophyics gives rise to radicle and root cap.
The terminal embryo cell under goes two vertical and one transverse division to form eight cells arranged in two tiers .It is the the octant stage of pro-embryo .
The lower tier of 4-cells give rise to plumule and cotyledons while the upper their of 4-cells near the suspensor gives rise to hypocotyl .
The octant pro-embryo divides periclinally to form outer single layer of dermatogen or protoderm from which the epidermis arises .
The inner cells divide further forming periblem internal to the dermatogen and plerome in the untre
The ground meristem produces cortex and pith where as procombium gives rise to stele.
Initially the embryo is globular and undifferentiated .
With continuous growth the globular pro-embryo becomes heart-shaped due to the development of two premordials of cotyledons.
Subsequent development gives rise to the dicot embryo which is horse-shoe shaped .
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