The most common way these trees undergo pollination is through seeds and pollen.
The pollination is done with help of wind and birds where pollen transform from one plant to another.
Explanation:
The plants that undergoes pollination process through the seeds that are present in it are called as Angiosperms. These contains fruits. The seeds are usually present inside these fruits. Flowering plants are also called as Angiosperms.
These fruits and flowers are absent in gymnosperm. Even then they contain seeds inside the leaves surface. They will undergo pollination with these naked seeds. It is the fruits, flowers and the endosperm that are present in the seeds that help us to find difference between these two. The only common thing that exists between these two are seeds and pollen with which they pollinate.
In gymnosperms, pollen is transferred from male cone to female cone through wind or birds. Now, the pollen is germinated into pollen tubes and sperm for egg fertilization.