Which term refers to a sex cell?

The term that refers to a sex cell is "gamete." In biological contexts, gametes are specialized cells that are involved in sexual reproduction; they carry half the genetic information necessary to form a new individual. In humans and many other organisms, the male gamete is called sperm and the female gamete is called an egg.

Gametes are distinct from somatic cells, which make up the vast majority of the body's cells and contain a complete set of chromosomes. Unlike somatic cells, gametes undergo meiosis, a special type of cell division that reduces the chromosome number by half, making them essential for the formation of a zygote when two gametes fuse during fertilization.

The term "fertility cell" is not commonly used in scientific terminology and lacks the specificity of "gamete." Similarly, "tissue cell" refers to any cell that makes up a specific tissue rather than a gamete. Therefore, "gamete" is the precise term to indicate a sex cell.