Final answer:
The pollen unites with the egg of a plant to form a zygote, which is the starting point for the development of a new plant.
Step-by-step explanation:
When the pollen unites with the egg of a plant, it forms a zygote. The zygote is the initial cell formed after fertilization and it contains the genetic material from both the pollen and the egg. It is the starting point for the development of a new plant.
Learn more about Plant reproduction