When the pollen tube enters the ovule through the funiculus or the integuments,it is called:

In the diagram given below,show the path of a pollen tube from the pollen on the stigma into the embryo sac. Name the components of the egg apparatus.

Which of the following stimulates pollen germination and pollen tube growth?

In wheat and rice,pollen grains lose viability within $30$ minutes of their release. In members of the families Rosaceae,Leguminosae,and Solanaceae,the viability is maintained for $...$.

In angiosperms,the pollen tube releases its male gametes into the .......

After penetrating the stigmatic and stylar tissues,the pollen tube usually grows down towards the egg because: