What is mature pollen?

thanks

What is mature pollen?
Just as a mature fruit is the one that is ready to drop from a tree ( discount here commercially ripened fruit ).



Just as a mature seed is the one that is ready to escape from a fruit and ready to germinate .



Like wise a mature pollen is the one that is ready to escape from an anther and to be carried away by the agents of pollination .



When anthers burst open one can say that the pollen is mature .



Now let us examine some photos =



1 ) In the link below you can see developing pollen grains inside anther lobes . click the link =

http://www.cartage.org.lb/en/themes/Scie...

2)In this link the anther lobes have opened and pollen is escaping =

http://www.biology.iastate.edu/Courses/2...



3 ) In this photo you can see anthers are smeared with pollen that is mature and come out of the anther lobes =

http://www.biology.iastate.edu/Courses/2...



4 ) This is a photomicrograph of mature pollen grains . Each has two nuclei i ) tube nucleus that produces the pollen tube after landing on the stigma. i i) Generative nucleus = forms two male gametes .

http://www.biology.iastate.edu/Courses/2...



5 ) Pollen tube on the stigma =

http://www.botany.hawaii.edu/faculty/web...
Reply:** old pollen?? I guess
Reply:Once the pollen lands on the stigma, a series of chemical reactions takes place allowing the pollen grain to begin producing a structure called the pollen tube. As this is happening, the generative nucleus will divide and produce 2 sperm nuclei. This pollen grain with the pollen tube and 3 nuclei is considered the mature gametophyte.