A pollen grain on the stigma grows a tiny tube, all the way down the style to the ovary. This pollen tube carries a male gamete to meet a female gamete in an ovule.
How does male gamete present in pollen grain reaches female gamete present in ovule Class 7?
Pollen grains bear the male gamate. When the pollen grains reach the stigma of a pistal, it germinates to give out a pollen tube. … The pollen tube grows to reach the ovary and the ovule. When the pollen tube reaches the ovule, it pushes the male gametes into the egg cell.
How does the male gamete reaches the female gamete?
The gametes will reach the female reproductive system through pollen tube. Then fusion happens, which results in the production of zygote.
How does sperm in a pollen grain reach an egg in the ovule?
The germ cell in the pollen grain divides and releases two sperm cells which move down the pollen tube. Once the tip of the tube reaches the micropyle end of the embryo sac, the tube grows through into the embryo sac through one of the synergids which flank the egg.
How male gametes are formed from a pollen grain?
Complete answer: Male gametes are formed by Generative cells. … The cell within the pollen grain divides unequally to make two cells called a generative cell and a vegetative cell. The vegetative cell provides nourishment. The generative cell divides mitotically to form the two male gametes.
How many nuclei are present in the pollen grain?
pollen grain A microspore in flowering plants, which germinates to form the male gametophyte, a structure made up of the pollen grain plus a pollen tube. The grain contains 3 haploid nuclei (a tube nucleus and 2 sperm nuclei), which pass down the tube to the ovum.
What happens to flower after fertilization?
After fertilization the flower withers. The sepals and the petals dry up, the ovary converts into fruit, the ovule forms the seed and the zygote forms the embryo which is enclosed in the seed.
What happens when male gamete reaches the ovule?
A pollen tube grows through the tissues of the flower until it reaches an ovule inside the ovary . The nucleus of the pollen grain (the male gamete ) then passes along the pollen tube and joins with the nucleus of the ovule (the female gamete). This process is called fertilisation .
Where will be the male and female gametes be just before fertilization?
Male gamete travels inside the pollen tube while female gamete is inside the ovule. Pollen tubes penetrate the ovule to release the male nuclei inside it, that why just before fertilization male gamete is at the end of pollen tube while gamete is inside the ovule.
What is the difference between a sperm cell and a pollen grain?
Each male gametophyte (pollen grains) will in turn produce two genetically identical sperm cells through mitosis. One sperm cell will fuse with the ovule, and the second with the central cell (that has two nuclei) to produce a triploid endosperm. … (d) Angiosperm pollen grains develop in the anthers.
What happens to the sperm released from the pollen grain?
After the pollen tube enters the female gametophyte, it ruptures and releases two sperm cells with its contents. The two sperm cells then move toward and fuse with the egg cell and central cell to produce embryo and endosperm, respectively.