The organ system that produces specialized cells to continue the human species is the reproductive system.

Here's why:

* Male Reproductive System: Produces sperm cells, the male gametes, which are specialized cells carrying half of the genetic material needed to create a new human.

* Female Reproductive System: Produces egg cells (ova), the female gametes, which also carry half of the genetic material needed for conception.

When a sperm cell fertilizes an egg cell, a new individual begins to develop. Therefore, the reproductive system is crucial for the continuation of the human species.