Here's why:

* Genetic Information: All living organisms have DNA, which contains the instructions for building and maintaining life.

* Diploid Cells: Most cells in your body (somatic cells) have two sets of chromosomes, one from each parent. This is called being diploid.

* Haploid Cells: Gametes (sperm and egg cells) only have one set of chromosomes. This is called being haploid.

* Fertilization: When a sperm cell and an egg cell fuse during fertilization, they combine their single sets of chromosomes to create a diploid zygote, which will develop into a new individual.

So, gametes are special cells that have half the genetic information necessary to create a new organism. This ensures that the offspring receives a complete set of chromosomes, half from each parent.