第二步
初級精母細胞不按其他細胞複製的方式那樣複製自己，而是以一種獨特的方式分裂。可以說，它分裂成兩半，分配給兩個新細胞各22條常染色體，一條X性染色體給方，一條Y性染色體給另一方。這兩個新的細胞叫次級精母細胞，每一個隻含有所有其他體細胞一半的染色體（23條）。

The Second Step
The primary spermatocyte does not duplicate itself the way all other cells do, but divides in a unique way: It splits in half, as it were, allotting 22 chromosomes plus 1 X chromosome to one of the new cells, and 22 chromosomes plus 1 Y chromosome to the other. The two new cells are called secondary spermatocytes, and each of them contains only half as many chromosomes (23) as all other body cells.