* Male sex cell: Sperm or Pollen grain (which contains the sperm)

* Female sex cell: Egg cell (also known as the ovum)

Important Note: While both sperm and pollen grain are involved in fertilization, it's crucial to understand their distinct roles:

* Pollen grain: The pollen grain is a protective outer layer containing the sperm cell.

* Sperm cell: The sperm cell is the actual male gamete that fuses with the egg cell during fertilization.

Let me know if you have any other questions!