this is because premature pollen grain do not contain the sperm cell for fertilization. only the generative nucleus in mature pollen grain will divide mitosisly to form sperm cell for fertilization
Pollen grains are produced by the male reproductive organs of flowering plants called anthers. Anthers contain pollen sacs where pollen grains develop and mature.
No. The stamen is the male structure of the flower, consisting of a filament and anther. However, the mature, male gametophyte consists of a germinated pollen grain with its tube and two associated sperm.
a single pollen grain is only one cell. A mature pollen grain in many plants have two cells as a result of pollen mitosis- 1. the tube cell and 2. the germ cell. The tube cell forms the pollen tube at the time of pollen germination and the germ cell nucleus divides again to form two male gametes.
No, sperm cells do not grow out of a pollen grain. In plants, sperm cells are produced within the pollen grain, and they are involved in fertilization when the pollen grain reaches a female reproductive structure. Each pollen grain contains two sperm cells.
After pollination, the pollen grain germinates on the stigma and grows a pollen tube down to the ovary. Fertilization occurs when the male gametes in the pollen tube combine with the female gametes in the ovule, forming a zygote.
Germination of the pollen grain typically occurs on the stigma of the carpel (female reproductive organ) in flowering plants. The pollen grain produces a pollen tube through which the male gametes travel to fertilize the ovule.
A mature pollen grain is typically referred to as a "mature male gametophyte" in botanical terms.
pollen grain
A polln grain after germination sends a pollen tube in the ovule to release male gametes near the egg cell or ovum.
Germination of pollen grains in flowering plants occurs on the stigma of the female reproductive structure called the pistil. The pollen grain produces a pollen tube that grows down through the style of the pistil, eventually reaching the ovary where fertilization takes place.
it depends on gymnosperm (naked seed) or angiosperm (flowering plant) this is the angiosperm - Another germination event during the life cycle of gymnosperms and flowering plants is the germination of a pollen grain after pollination. Like seeds, pollen grains are severely dehydrated before being released to facilitate their dispersal from one plant to another. They consist of a protective coat containing several cells (up to 8 in gymnosperms, 2-3 in flowering plants). One of these cells is a tube cell. Once the pollen grain lands on the stigma of a receptive flower (or a female cone in gymnosperms), it takes up water and germinates. Pollen germination is facilitated by hydration on the stigma, as well as the structure and physiology of the stigma and style.[1] Pollen can also be induced to germinate in vitro (in a petri dish or test tube).[3][4] During germination, the tube cell elongates into a pollen tube. In the flower, the pollen tube then grows towards the ovule where it discharges the sperm produced in the pollen grain for fertilization. The germinated pollen grain with its two sperm cells is the mature male microgametophyte of these plants.[1
"Pollination is the transfer of the pollen grain from the anther to the stigma, where the pollen grain germinates, and becomes the mature male gametophyte." Source= Inquiry into Life Lab Manual. Therefore, the answer may be the mature male gametophyte...OR that it replaces a males sperm, depending on what your teacher is looking for. Hope this helps
A pollen grain is a mature microspore that consists of two cells (generative cell and tube cell) enclosed within a protective wall. A microspore is a haploid cell produced in the sporangia of seed plants that eventually develops into a pollen grain through the process of microsporogenesis.
Pollen grains are produced by the male reproductive organs of flowering plants called anthers. Anthers contain pollen sacs where pollen grains develop and mature.
No. The stamen is the male structure of the flower, consisting of a filament and anther. However, the mature, male gametophyte consists of a germinated pollen grain with its tube and two associated sperm.
pollen grains are the powdery pollens in the pollen sacs . Pollen sacs are situated in the anther. For a pistil to develop into a fruit and ovules to mature into seeds, pollen grains must be transfered from anthers to the stigma. This process is called pollination.
Ungerminated pollen grain is inactive and has not started the process of fertilization, while germinated pollen grain has started growing a pollen tube towards the ovule for fertilization. Germinated pollen grain is actively involved in the fertilization process, while ungerminated pollen grain is not.