The cells directly involved in reproduction are the gametes. These are specialized cells that carry half the genetic information of an organism.

Here's a breakdown:

* Sperm cells (male gametes): Produced in the testes, these are small, motile cells that carry the male genetic contribution.

* Egg cells (female gametes): Produced in the ovaries, these are large, non-motile cells that carry the female genetic contribution.

The process of fertilization involves the union of a sperm cell and an egg cell, resulting in a zygote, the first cell of a new organism.

Here are some other cells that play supporting roles in reproduction:

* Follicle cells: These cells surround and nourish the developing egg cell in the ovary.

* Sertoli cells: These cells support and nourish developing sperm cells in the testes.

* Leydig cells: These cells produce testosterone, the male sex hormone.

* Granulosa cells: These cells help produce estrogen, the female sex hormone.

Let me know if you'd like to learn more about any of these cells or the reproductive process!