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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 a
- a 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
Wiki User
∙ 11y ago
Wiki User
∙ 14y agoThe pollen grain contains the maile sperms cells and the ovule the female egg cell
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Is there pollen grain inside the pollen cell?
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.
In plants do kalanchoe form between the two new neclei?
Each nucleus divides by mitosis to become two nuclei. One is the tube nucleus. The other is a generative nucleus. The wall of the cell thickens to protect the developing pollen grain. As the anther ripens, the wall between the paired pollen sacs disappears. The pollen sacs burst open and the mature pollen grains are ready for dispersal. Each ovary contains one or more ovules. The green structure at the top of the diagram is the ovule. The integuments are the 2 walls of the ovule. There is a small opening in the walls called a micropyle. This is where the pollen tube will enter. The nucellus is cells that provide nutrition for the growth of the ovule. The embryo sac, also known as the megaspore, divides by meiosis to form 4 haploid cells. Three of these cells degenerate and one remains. Only one megaspore survives in each ovule. This becomes the embryo sac. The haploid nucleus of the surviving megaspore undergoes three mitotic divisions. Eight haploid nuclei are now present. Within the swollen 'megaspore cell' six haploid cells and two 'polar nuclei' are formed. The entire structure is called the embryo sac.
What structures are found in the anthers?
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.
What happens to gymnosperms during pollination?
Gymnosperms do not produce flowers (as opposed to angiosperms), so there is nothing to attract pollinating insects. As a result, they depend on the wind to blow the pollen from the male to the female cones. Pollination can also occur if the male cones are present at the same time and situated above the female cones. In this case self-pollination can occur when the pollen simply falls or blows downward.
Describe fertilization and where it occurs?
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.
How do the sperms nuclei in a pollen grain reach the egg nucleus in an ovule?
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.
What happens when two pollen grains land on the same stigma and after the first grain fertilises the ovule?
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)
What do you call the yellow powder in flowers?
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.
How many male sex cells does each pollen grain contain?
One.
How do the sperm nuclei in a pollen grain reach the egg nucleus in an ovule?
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.
What is the function of the pollen tube?
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).
What process happens when pollen falls on a flowers pistil?
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.
Is there pollen grain inside the pollen cell?
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.
What is flower fertililzation?
Flower fertilization is when the pollen gets into the female parts of the flower and the seeds start to form. Each ovule or egg needs some pollen to form a seed.
what sre pollens?
a fine powdery substance, typically yellow, consisting of microscopic grains discharged from the male part of a flower or from a male cone. Each grain contains a male gamete that can fertilize the female ovule, to which pollen is transported by the wind, insects, or other animals.
What do micro spores develop into?
Each microspore can develop into a male gametophyte,or pollen grain
What do pollen and sperms both do on a plant?
Scientifically speaking the term sexual reproduction simply means that two components (gametes) are required for production of a new generation (offspring). Each of the two components carries in it one half of the chromosomes of any normal cell in the parent which produced it. The sperm is usually the gamete that moves away from its parent to join the gamete from the more stationary parent. Pollen is a special case. Each grain contains a nucleus that "directs" the growth of the pollen tube and germ cells (sperm) that ultimately join with the gamete from the ovule and form an embryo. So, in answer to your question, pollen contains the sperm cells. As the pollen fly away, they land on the bulb of the flower and tiny tubes form from the pollen to the ovules. The sperm then moved to the ovule through the tube and fertilizes the flower.
