Which structure contains the genetic material in a sperm cell?

The nucleus is the structure in a sperm cell that contains the genetic material. In the case of sperm, the nucleus holds the DNA, which is crucial for passing genetic information to the egg upon fertilization. This DNA is tightly packaged in the nucleus to ensure it stays protected and is efficiently delivered during reproduction.

The other structures mentioned do not contain the genetic material. For instance, the cytoplasm is involved in various cellular processes but does not store DNA. The cell membrane serves as a protective barrier for the cell and regulates the movement of substances in and out but does not store genetic information. The flagellum is responsible for the motility of the sperm, allowing it to swim towards the egg but does not contain any genetic material either. Thus, the nucleus stands out as the vital component for genetic inheritance in sperm cells.