Name: Pollination
Uploaded: 2019-07-19
Duration: 5 min 53 s
Description: Pollination is the act of transferring pollen grains from the male anther of a flower to the female stigma. Here, learn more about pollination and its types.

Question

What is the function of pollen tube? Trace its path from stigma to the female gamete by means of a diagram.

Accepted Answer

The pollen tube is a long, thin structure that grows out of a pollen grain after it lands on the stigma of a flower. The pollen tube contains two male gametes (sperm cells), and its function is to transport these gametes to the ovule, where they can fertilise the egg cell.

The journey of the pollen tube from the stigma to the ovule is a long and complex one. The pollen tube must first grow through the stigma and style, the two parts of the flower that connect the stigma to the ovary. The style is made up of soft tissue that the pollen tube can easily dissolve. The stigma, on the other hand, is made up of hard tissue that the pollen tube must secrete enzymes to dissolve. Once the pollen tube reaches the ovary, it must then enter the ovule through the micropyle that is guarded by two cells called the synergids. The pollen tube must secrete enzymes to dissolve the synergids in order to enter the ovule.

Once the pollen tube enters the ovule, it travels down to the egg cell. The pollen tube then releases the two sperm cells. One sperm cell fertilises the egg cell, and the other sperm cell fertilises the central cell. This process is called double fertilisation, and it is unique to flowering plants. Double fertilisation is essential for the development of a new plant. The sperm cell that fertilises the egg cell creates the embryo, which will become the new plant. The sperm cell that fertilises the central cell creates the endosperm, which is a nutrient-rich tissue that nourishes the embryo.

What is the function of pollen tube? Trace its path from stigma to the female gamete by means of a diagram.

Important Questions on Pollination and Fertilisation

Learn and Prepare for any exam you want !