In Seed-Bearing Plants, What Structure Becomes the Seed Following Fertilization?

In Seed-Bearing Plants What Structure Becomes The Seed Following Fertilization – In Seed-Bearing Plants, What Structure Becomes the Seed Following Fertilization? This question delves into the intricate processes of plant reproduction, revealing the remarkable transformation that occurs within the ovule after fertilization.

As the ovule embarks on its journey towards becoming a seed, it undergoes a series of fascinating changes. The integuments, protective layers surrounding the ovule, develop into the seed coat, safeguarding the developing embryo within. Meanwhile, the endosperm, a nutrient-rich tissue, emerges as a vital source of nourishment for the growing plant.

The Ovule: The Precursor to the Seed

The ovule is a small structure within the ovary of a flowering plant that contains the female gamete, or egg cell. It consists of several layers of protective tissue, including the integuments, which surround the nucellus, where the egg cell is located.

The micropyle is a small opening in the integuments through which the pollen tube enters during fertilization.When a pollen grain lands on the stigma of a flower, it germinates and produces a pollen tube that grows down the style and into the ovary.

The pollen tube contains the male gametes, or sperm cells. When the pollen tube reaches the ovule, it releases the sperm cells, which fertilize the egg cell. The fertilized egg cell is called a zygote.After fertilization, the ovule undergoes a series of changes that transform it into a seed.

The integuments harden and become the seed coat, which protects the embryo from damage. The nucellus develops into the endosperm, which provides nutrients for the embryo. The zygote develops into the embryo, which consists of the radicle, or root, the plumule, or shoot, and one or two cotyledons, or seed leaves.

The Integuments

The integuments are the protective layers that surround the ovule. They consist of two layers: the outer integument and the inner integument. The outer integument is composed of a thick layer of cells that are filled with lignin, a hard, woody substance that provides strength and protection.

The inner integument is composed of a thinner layer of cells that are filled with starch, a carbohydrate that provides nutrients for the developing seed.

Role of the Integuments

The integuments play an important role in protecting the developing seed. They protect the seed from physical damage, desiccation, and pathogens. The outer integument is particularly important in protecting the seed from physical damage, while the inner integument is particularly important in protecting the seed from desiccation and pathogens.

Development of the Seed Coat

The seed coat develops from the integuments after fertilization. The outer integument becomes the hard, outer layer of the seed coat, while the inner integument becomes the softer, inner layer of the seed coat. The seed coat is important for protecting the seed during dormancy and germination.

The Endosperm: The Nutrient Reservoir

Following fertilization, the endosperm develops from the fusion of one of the male gametes with the two polar nuclei of the female gametophyte. It is a triploid tissue that surrounds the embryo and provides nourishment during its development.

The endosperm is composed primarily of starch, proteins, and lipids. These nutrients are synthesized within the endosperm itself or transported from the surrounding maternal tissues. The endosperm also contains enzymes that break down these nutrients into forms that can be utilized by the embryo.

Role in Providing Nutrients to the Developing Embryo, In Seed-Bearing Plants What Structure Becomes The Seed Following Fertilization

The endosperm plays a vital role in providing nutrients to the developing embryo. The nutrients stored within the endosperm are gradually released as the embryo grows and develops. This process is regulated by hormones produced by both the embryo and the endosperm.

In some plants, the endosperm is completely consumed by the embryo during development. In other plants, the endosperm persists as a storage tissue in the mature seed. This endosperm can provide nutrients to the germinating seedling until it can establish its own root system and begin to photosynthesize.

The Embryo: In Seed-Bearing Plants What Structure Becomes The Seed Following Fertilization

The embryo is the immature plant that develops from the zygote following fertilization. It consists of a radicle, a hypocotyl, and one or two cotyledons.

The radicle is the embryonic root, which grows down into the soil to anchor the plant and absorb water and nutrients. The hypocotyl is the stem of the embryo, which connects the radicle to the cotyledons. The cotyledons are the first leaves of the embryo, which provide nourishment to the developing plant until it can photosynthesize on its own.

Embryo Development

Embryo development begins with the zygote, which is formed by the fusion of the male and female gametes. The zygote undergoes a series of cell divisions, forming a ball of cells called the proembryo. The proembryo then differentiates into the radicle, hypocotyl, and cotyledons.

The development of the embryo is controlled by a variety of genetic and environmental factors. The genes of the parent plants determine the basic structure of the embryo, while the environment can influence the size and shape of the embryo.

Tissue and Organ Differentiation

As the embryo develops, its cells begin to differentiate into different tissues and organs. The radicle develops into the root system, the hypocotyl develops into the stem, and the cotyledons develop into the leaves. The embryo also develops a variety of other tissues and organs, including the vascular system, the shoot apical meristem, and the root apical meristem.

The differentiation of tissues and organs within the embryo is a complex process that is essential for the development of a healthy plant.

Ending Remarks

In conclusion, the structure that becomes the seed following fertilization in seed-bearing plants is the ovule. Through a series of intricate transformations, the ovule’s integuments form the protective seed coat, while the endosperm provides essential nutrients for the developing embryo.

This process ensures the successful development and dispersal of seeds, perpetuating the life cycle of these remarkable plants.