Remnants of Nucellus in a Seed

Introduction:
Seeds are the reproductive structures of the higher plants. They are formed after fertilization of the ovules by the pollen grains. The ovules consist of the nucellus, which is an important part of the ovule. After fertilization, the nucellus degenerates and forms some structures, which are known as the remnants of the nucellus.

Perisperm:
Perisperm is a nutritive tissue that surrounds the embryo in some seeds. It is formed by the proliferation of the nucellus cells after fertilization. The perisperm is rich in nutrients and helps in the development of the embryo.

Endosperm:
Endosperm is a nutritive tissue that is formed after fertilization in some plants. It is formed by the fusion of the male and female nuclei in the embryo sac. The endosperm is rich in nutrients and helps in the development of the embryo.

Pericarp:
Pericarp is the outer layer of the fruit that develops from the ovary after fertilization. It consists of three layers, the exocarp, mesocarp, and endocarp. The pericarp protects the seed and helps in its dispersal.

Cotyledon:
Cotyledon is a part of the embryo that develops into the first leaves of the plant. It is present in the seeds of the dicotyledonous plants. The cotyledons are rich in nutrients and help in the development of the embryo.

Conclusion:
The remnants of the nucellus in a seed are known as perisperm. It is a nutritive tissue that surrounds the embryo and helps in its development. The other important parts of a seed are endosperm, pericarp, and cotyledon, which are also involved in the development and protection of the embryo.