Answer:
Through Pollination
Step-by-step explanation:
In pollination, the pollen grains of one plant/trees are carried off by carries (insects, wind etc.) and dropped at the ovary with in the flower of other plant/trees. This allows crossing between two plants/trees which are located far away from each other. This happens with asexual plants/ trees (which have only one sex) However in case of bisexual trees/plants (with both the male and female sex on the same plant) there is no requirement of pollination.