Answer:
- Delivery of the sperm to the female gametophyte
- Protection of the male gametophyte
Explanation:
The pollen grain is a microspore present in angiosperms and gymnosperms, it contains the male gametophyte.
The pollen tube present in pollen grains and the way they are transported (by wind) allows these plants to require no water for reproduction.
In addition, the pollen grain has two very resistant walls (internal and external), composed mainly of cellulose, ensuring protection to the male gametophyte until it meets the female gamete.