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Fertilization is occurred when ripe pollen from an anther of the same kind of flower catches on the stigma, each pollen grain sends out a tiny threadlike tube. The tube grows down through the style and pierces one of the ovules in the ovary. This process is called fertilization.
Pollen grains contain the male gametes required for sexual reproduction of a plant/ flower. These are haploid, and only contain half the full set of chromosomes; the other half is contributed by the female gamete (or ovule).A grain of pollen contains:a larger vegetative cell (also called the tube cell) inside of which is aa smaller germ cell (also called the generative cell).The pollen grain "germinates" on the stigma of the receptive flower and grows down the style, once it reaches the ovule the germ cell/ nucleus fuses with the nucleus of the ovule and an embryo is formed
A single pollen grain contains the generative material that forms the male gametes. It also contains the material that will form the pollen tube when the pollen lands on the pistil. These are covered by a thin layer called the intine or endospore as well as a thick protective wall called the exine or exospore.
Because conifers are pollinated by wind hence to ensure fertilization of each egg clouds of pollen grains are formed.
The female structure of the flower is the gynoecium that is made up of the ovary, style and stigma. The ovary produces the ovule. The male structure is the androecium. It is made up of the filament and anther. The filaments bear the anthers. The anthers produce pollen.
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When a pollen grain lands on stigma, pollination occurs. The pollen grain germinates and the pollen tube grows through the style. The sperm nucleus travels through the tube (generated by the tube nucleus) and fuses with an ovule which then develops into an embryo (or zygote)
Each microspore can develop into a male gametophyte,or pollen grain
Fertilization is occurred when ripe pollen from an anther of the same kind of flower catches on the stigma, each pollen grain sends out a tiny threadlike tube. The tube grows down through the style and pierces one of the ovules in the ovary. This process is called fertilization.
The two nuclei found inside each pollen grain are called tube nucleus and germ nucleus.
Pollen grains contain the male gametes required for sexual reproduction of a plant/ flower. These are haploid, and only contain half the full set of chromosomes; the other half is contributed by the female gamete (or ovule).A grain of pollen contains:a larger vegetative cell (also called the tube cell) inside of which is aa smaller germ cell (also called the generative cell).The pollen grain "germinates" on the stigma of the receptive flower and grows down the style, once it reaches the ovule the germ cell/ nucleus fuses with the nucleus of the ovule and an embryo is formed
You are describing pollen grains. Each grain contains a male gamete that can fertilize the female ovule, to which pollen is transported by the wind, insects, or other animals.
The pollen tube of most seed plants acts as a conduit to transport sperm cells from the pollen grain, either from the stigma (in flowering plants or angiosperms) to the ovules at the base of the pistil, or directly through ovule tissue in some gymnosperms (conifers and gnetophytes).
A single pollen grain contains the generative material that forms the male gametes. It also contains the material that will form the pollen tube when the pollen lands on the pistil. These are covered by a thin layer called the intine or endospore as well as a thick protective wall called the exine or exospore.
Pollination brings together the gametes of a flower and it occurs when a pollen grain of the right kind lands on the stigma of the pistil. Each pollen forms a tube that grows down through the pistil and reaches the ovule in the ovary. One of the nuclei in the pollen tube unites with the egg nucleus in the ovule to form a zygote. The other sperm nucleus combines with another bigger nucleus in the ovule which develops into the endosperm.
When they land on the style they begin to bore their way through the stigma all the way to the ovule. Through the tube made by the tube nucleus of the pollen grain: each pollen grain has two nuclei, one called generative nucleus which combines with the nuclei of the ovule, and the other called tube nucleus tube nucleus which forms a tube that penetrates the stigma till it reaches ovule then it degenerates.
The pollen for each kind of tree or flower is distinctive to that species, so there is no definite description for what pollen in general looks like - the grains aren't even all round; the size also varies: for instance, a grain of pollen from an elm tree (which is round) is about 20 micrometers in diameter, whereas a pollen grain from a Scots pine tree is kinda kidney shaped, & measures about 40 x 60 micrometers