The single cell that reproduces itself after conception is the zygote.

Here's why:

* Conception: When a sperm cell fertilizes an egg cell, it forms a zygote.

* Zygote Division: The zygote undergoes a process called mitosis, where it divides into two identical daughter cells. This process continues, leading to the development of a multicellular organism.

So, the zygote is the starting point for all the cells in your body.