Question

Why does endosperm development precedes embryo development in angiosperm seed? State the role of endosperm in mature albuminous seeds.

Answer 1

Hint: After double fertilisation, endosperm is a tissue formed within the seeds of most flowering plants. Most animals are triploid, which means they have three chromosome sets per nucleus.

Complete answer:
Following fertilisation, endosperm is a tissue formed within the seeds of most flowering plants. Most animals are triploid (meaning they have three chromosome sets per nucleus). It envelops the embryo and provides nutrients in the form of starch, though it may also contain oils and proteins.
The plant embryo, also known as the seed embryo, is the portion of a seed or bud that comprises the plant's roots, stem, and leaves in their earliest forms. After a fertilised adult plant flowers, the embryo develops and is usually enclosed inside a seed or bud.
Role of endosperm:
During seed production and germination, the endosperm plays an important role in promoting embryonic growth by supplying nutrients, protecting the embryo, and regulating embryo growth by acting as a mechanical barrier.
Since the endosperm cells provide nutrients to the developing embryo, endosperm growth occurs before that of the embryo in angiosperm seeds. Endosperm serves as storage tissue in mature albuminous seeds. It is capable of storing both starch and fat.

Note:
The key distinction between embryo and endosperm is that the embryo represents the principle of fertilisation, whereas the endosperm represents the seed's nutritive tissue. It is made up of the nucleus of the primary endosperm. It's a gametophyte with a female reproductive system. It contains an egg cell for fertilisation purposes.