Here's why:

* 22 autosomes: These are the non-sex chromosomes, present in pairs (one from each parent) in all human cells.

* Y chromosome: This is one of the two sex chromosomes. Males have an X and a Y chromosome, while females have two X chromosomes.

* Germ cell: These are the cells that produce gametes (sperm and eggs). Germ cells undergo meiosis, a special type of cell division that reduces the number of chromosomes by half. This is why sperm cells only have one set of chromosomes, including a single Y chromosome.

Important note: Somatic cells (all cells in the body except germ cells) have a full set of 46 chromosomes, including 22 pairs of autosomes and a pair of sex chromosomes.