What is the Difference Between Germinated and Ungerminated Pollen Grain

Germinated pollen grain refers to the pollen grains with a tube cell elongated into a pollen tube while ungerminated pollen grain refers to the pollen grains which have not absorbed water.

1. What is pollen germination?
2. What is a mature pollen grain?
3. Where does germination of a pollen grains occur?
4. Why do pollen grains fail to germinate?
5. Where do the pollen germinate naturally?
6. Which of the following is required for pollen germination?
7. How is pollen grain formed?
8. Which of these is contained in a pollen grain?
9. What are the three components of a pollen grain?
10. Where does the germination of the pollen grain takes place and how?
11. How pollen grains germinate in female part of a plant?
12. What is the function of pollen tube?

What is pollen germination?

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.

What is a mature pollen grain?

Mature pollen grains contain two cells: a generative cell and a pollen tube cell. The generative cell is contained within the larger pollen tube cell. ... During its transit inside the pollen tube, the generative cell divides to form two male gametes (sperm cells).

Where does germination of a pollen grains occur?

Pollen germination starts with the pollen grain landing on stigma. The cell of the pollen grain divides into two cells- one of these is smaller in size and called generative cell and bigger one is called tube cell. The intine grows out through the germ pore and form pollen tube.

Why do pollen grains fail to germinate?

1)Some pollen grains fail to germinate as they don't get all the essential conditions for the germination of pollen. ... The stigma of flower receives different kinds of pollen, but pollen belonging to same species grows and survive and rest of the pollens fail to grow. 4)No, pollen tubes are not of equal length.

Where do the pollen germinate naturally?

The pollen grains germinate naturally on the stigma of compatible flower. They develop pollen tubes that helps to deliver sperm nuclei inside the embryo sac where fertilization takes place.

Which of the following is required for pollen germination?

Boron is required for pollen germination, cell elongation and carbohydrate translocation.

How is pollen grain formed?

Pollen is produced within the anthers (microsporangia or pollen sacs) of the flower. During its development from an undifferentiated mound of cells (anther primordium) the anther forms two general groups of cells.

Which of these is contained in a pollen grain?

Each pollen grain contains vegetative (non-reproductive) cells (only a single cell in most flowering plants but several in other seed plants) and a generative (reproductive) cell. In flowering plants the vegetative tube cell produces the pollen tube, and the generative cell divides to form the two sperm nuclei.

What are the three components of a pollen grain?

Most pollen grains consist of three distinct parts. The central cytoplasmic part is the source of nuclei responsible for fertilization. The other parts constituting the wall of the grain are an inner layer, the intine, and an outer layer, the exine. The intine consists, at least in part, of cellulose or hemicellulose.

Where does the germination of the pollen grain takes place and how?

It takes place in the stigma of the female flower. Pollen grain divides into 2 cell.. 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.

How pollen grains germinate in female part of a plant?

After a pollen grain lands on a receptive stigma of a pistil, a pollen tube germinates from the hydrated pollen grain and delivers the immotile sperm cells over a long distance toward the ovule. A pollen tube is a tip-growing cell that grows surprisingly fast.

What is the function of pollen tube?

In angiosperms, the pollen tube is siphonogamous and its main function is to carry the male gametes for double fertilization. In some taxa, as in Cucurbitaceae, the tube branches after entering the ovule, prior to fertilization.