Describe double fertilization in plants. Describe double fertilization in plants​ 2022-11-17

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Double fertilization is a process that occurs in flowering plants during sexual reproduction. It is the fusion of two gametes, the male sperm and the female egg, to form a zygote, which will eventually develop into a seed.

The process begins when the male gametophyte, or pollen grain, lands on the stigma, or receptive surface, of the female flower. The pollen grain then germinates and grows a tube through the style, or stalk, of the flower and into the ovary, where the ovules, or immature seeds, are located.

Inside the ovary, the pollen tube releases two sperm cells, one of which fertilizes the egg cell, forming a zygote. The other sperm cell fertilizes the central cell, which will eventually develop into the endosperm, a nutrient-rich tissue that nourishes the developing seed.

This process is known as double fertilization because it involves the fusion of two gametes, the egg and the sperm, and the formation of two different tissues, the zygote and the endosperm.

Double fertilization is a unique feature of flowering plants and is responsible for the production of seeds, which are the means by which these plants reproduce and disperse their offspring. Without double fertilization, flowering plants would not be able to reproduce and would eventually become extinct.

In addition to its importance in sexual reproduction, double fertilization also has important implications for plant evolution and diversity. By producing seeds, flowering plants are able to colonize new environments and adapt to changing conditions, leading to the development of a wide variety of plant species.

Overall, double fertilization is a vital process in the reproductive biology of flowering plants, enabling them to produce seeds and reproduce sexually. It is a key factor in the success and diversity of these plants, and has had significant impacts on the evolution of the plant kingdom.

Double Fertilization

describe double fertilization in plants

Double fertilization has a couple of advantages. The two sperm cells are discharged into the embryo sac. In angiosperms, one sperm fertilizes the egg to form the 2 n zygote, and the other sperm fertilizes the central cell to form the 3 n endosperm. The suspensor provides a route for nutrition to be transported from the mother plant to the growing embryo. Soon after pollination the pollen grains start germinating and form a pollen tube. The germination of the pollen tube requires water, oxygen, and certain chemical signals. The fusion of one male gamete with egg and that of another male gamete with a secondary nucleus is called double fertilisation.

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What is double fertilization? Describe the process in brief.

describe double fertilization in plants

After fertilization, the zygote divides to form an upper terminal cell and a lower basal cell. It produces genetic variations by mixing the characters from the two parents that lead to the evolution of a new species. After fertilization: i The Ovary of the flower develops and becomes a fruit. The product formed is termedas zygote. The other sperm fuses with the two polar nuclei, resulting in a triploid cell.

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What is Double Fertilisation? Describe the Process in Brief.

describe double fertilization in plants

The pollen tube grows within the style till it reaches the ovary. Later, the cytokinesis makes the endosperm cellular. This is called a double fertilization. The embryo sac is contained by the ovule surrounded by two layers of integuments. Ans: The concept of double fertilisation was discovered by the Russian scientist S.

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Describe double fertilisation in plants.

describe double fertilization in plants

The ovary of a flower contains one or more ovules, which in turn contain the embryo sac. Summary Double fertilisation is a complex process of the fusion of haploid male gametes with the haploid egg nucleus to form the diploid zygote and the fusion of another haploid male gamete with the diploid polar nucleus to form the triploid primary endosperm nucleus. The zygote divides to form two cells: the upper cell terminal cell and the lower cell basal cell. The pollen tube cell grows into a pollen tube through which the generative cell travels. After fertilisation, the ovule develops into seed and the ovary develops into a fruit. Thus, inside each embryo sac two fusions, i. Double fertilization is a major characteristic of flowering plants.

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Describe the process of double fertilisation in plants.

describe double fertilization in plants

Fig: a A Typical Dicot Embryo, b L. So, fruit can be defined as a mature ovary containing seeds. In this process three nuclei, two polar nuclei and one male gamete is involved, so it is called triple fusion. Evidence suggests that the synergids secrete chemical signals to guide the pollen tube near the egg cell. The residual, persistent nucellus is called perisperm, e.

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Double fertilization

describe double fertilization in plants

Gamete: a sexual reproductive cell that is haploid and fuses with another gamete during fertilization resulting in a diploid zygote. In this case, the food reserves are moved into the two cotyledons. This process is known as syngamy or generative fertilization. Important Points About Double Fertilisation Double fertilisation was discovered more than a century ago by Sergei Navashin in Kiev in the Russian Empire and by Leon Guignard in France. However, with the development of the electron microscope, many questions were answered.

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Double Fertilisation: Importance, Discovery, Significance

describe double fertilization in plants

The process of double fertilisation is not possible without microsporogenesis formation of pollen , megasporogenesis formation of embryo sac and pollination transfer of pollen from the anther to the stigma either of the same flower or of the different flower but of the same species. Together, these two fertilization events in angiosperms are known as double fertilization. After fertilization, the zygote divides to form an upper terminal cell and a lower basal cell. The nutrients are transferred from the endosperm to the growing cotyledons and the mature seed does not have an endosperm anymore. Pollen grains are transported to the female part of another flower through pollination.

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Describe double fertilization in plant.

describe double fertilization in plants

The developing seedling will rely on the food reserves stored in the cotyledons until the first set of leaves begin photosynthesis. This occurs inside the ovule that is enclosed by the ovary in the flower. In this, the first mitotic division is followed by cytokinesis forming two unequal cells, and the subsequent divisions are free nuclear. The developing seedling will rely on the food reserves stored in the cotyledons until the first set of leaves begin photosynthesis. It is commonly seen in flowering plants or angiosperms. Besides the formation of a highly nutritious endosperm that increases the survival probability of the embryo, double fertilization is thought to avoid the waste of resources to form a nutritious tissue if fertilization does not occur.

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Double Fertilization in Plants: Definition & Diagram

describe double fertilization in plants

In dicots eudicots , the developing embryo has a heart shape due to the presence of the two rudimentary cotyledons. This recognition prevents the germination of the pollen if it lands on the pistil of a different species, and avoids self-fertilization in bisexual flowers of some pollen tube is a long and slender tube that goes all the way down through the style and reaches the interior of the ovary. In this process, two male gametes fuse with one female gamete wherein one male gamete fertilizes the egg to form a zygote, whereas the other fuses with two polar nuclei to form endosperm. Here we focus on the fertilization process that occurs after the male gametophyte reaches the pistil of another flower. Fig: Development of Embryo Sac. Monocotyledon species like rice, corn, and most cereal grains have embryos with only one thin cotyledon and the endosperm usually keeps its nutrients until the seed matures. In non-endospermic dicots, such as Capsella bursa, the endosperm develops initially, but is then digested, and the food reserves are moved into the two cotyledons.

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