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Sperm nuclei tube nucleus

Double fertilization is a complex fertilization mechanism of flowering plants angiosperms. This process involves the joining of a female gametophyte megagametophyte , also called the embryo sac with two male gametes sperm. It begins when a pollen grain adheres to the stigma of the carpel , the female reproductive structure of a flower. The pollen grain then takes in moisture and begins to germinate , forming a pollen tube that extends down toward the ovary through the style. The tip of the pollen tube then enters the ovary and penetrates through the micropyle opening in the ovule.
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The behavior of nuclei in germinating pollen grains of wheat, rice and maize

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Pollen | dynamic-fitness-solutions.com

The pollen grain is actually the male gametophyte generation of seed plants see reproduction. Inside the anther, pollen mother cells divide by meiosis to form pollen grains whose nuclei contain half the number of chromosomes characteristic of the parent plant. Each pollen grain contains two sperm nuclei and one tube nucleus. After successful pollination , the pollen germinates on the surface of the stigma of the pistil and produces a tube that grows down through the style to an ovule inside the ovary at the base of the pistil.
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Generative nucleus

Two sperm cells are required to achieve double fertilization in flowering plants angiosperms. In contrast to animals and lower plants such as mosses and ferns, sperm cells of flowering plants angiosperms are immobile and are transported to the female gametes egg and central cell via the pollen tube. The two sperm cells arise from the generative pollen cell either within the pollen grain or after germination inside the pollen tube. While pollen tube growth and sperm behavior has been intensively investigated in model plant species such as tobacco and lily, little is know about sperm dynamics and behavior during pollen germination, tube growth and sperm release in grasses.
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Pollen grains from the greek palynos for dust or pollen contain the male gametophyte microgametophyte phase of the plant. Pollen grains are produced by meiosis of microspore mother cells that are located along the inner edge of the anther sacs microsporangia. The outer part of the pollen is the exine , which is composed of a complex polysaccharide, sporopollenin. Inside the pollen are two or, at most, three cells that comprise the male gametophyte.
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