Question

Endosperm development precedes embryo development. Why?

Answer 1

An embryo is the early stage of development of a multicellular organism. Generally, in organisms that reproduce sexually, embryonic development is a part of the life cycle that begins just after fertilization and continues through the formation of body structures, like tissues and organs.

Complete answer:
The endosperm is produced from the first endosperm nucleus, which is produced by triple fusion because the second male gamete fuses with the 2 polar nuclei during fertilization. The endosperm provides nutrition to the growing embryo, hence, endosperm development precedes embryo development.
Endosperm provides nourishment to the developing embryo; thus, embryo development starts after an endosperm is made. The main role of the endosperm is to supply food for growing embryos.
Since the endosperm cells provide nutrients to the developing embryo, endosperm growth occurs before that of the embryo in angiosperm seeds. Endosperm is a storage tissue in mature albuminous seeds.
Endosperm is made when the 2 sperm nuclei inside a pollen grain reach the inside of a female gametophyte (sometimes called the embryo sac). That cell created within the process of double fertilization develops into the endosperm.
Nuclear endosperm is made by the free nuclear division and cell membrane formation doesn't occur. It's the foremost common type of endosperm in most of the plants.

Note:
A totally developed embryo of dicotyledons has an embryonal axis differentiated into plumule, two cotyledons and radicle. Stages of embryo development during a dicot angiosperm. Within the beginning the embryo is globular. When two cotyledons differentiate from the edges with a faint plumule within the center, the embryo becomes heart-shaped.