a) Why does endosperm development precede development in angiosperm seeds? State the role of endosperm in mature albuminous seeds.
b) Describe with the help of three labelled diagrams the different embryonic stages that include mature embryo of dicot plants.

Explanation

a) The development of endopserm preceds that the embryo in angiosperm seeds, because the endosperm cells provide nutrition to the develoment embryo. In mature albuminous seeds, endosperm exists as strong as strong tissue. It stores starch and fat.
b) Development of embryo: The enzymes starts dividing and gives rise to proembryo. This proembryo further divides forming a globular, heart-shaped and mature embryo.
Following are the steps that occur during the development of embryo:
1) The embryo develops at the microplyar end of the embryo sac where the zygote is situated.
1) The embryo deveops at the micropylar end of the embryo sac where the zygote is sitauated.
2) First, the zygote give rise to proembryo and, then, to the globular, heart-shaped, mature embryo.
3) A typical dicot embryo consists of an embryonal axis and two cotyledons.
4) The portion of the embryonal axis above the level of cotyledons is called epicotyl. It contains the plumule (shoot tip). The portioin below the axis is called hypocotyl. It contains the radicle (root tip). The root tip is covered by the root cap.