Genes!

We all start as a single cell that gets fertilized by a sperm. That single cell creates a copy of itself to become 2 cells. The 2 do the same to become 4, 4 become 8, and so on. At a certain point, you have enough cells to start differentiating and giving the cells a “job”. Your cells know where they are in your body by communicating with the cells around it, and that influences what job the cell should have.

Genes are a sequence of DNA, and certain genes serve as a “recipe” for proteins which do a lot of important work in the cell. The cell’s job determines which genes are used and therefore which proteins are made. The genes provide the information needed for the cells to form a certain way (look like a nose) and function a certain way (behave like a nose) and proteins help facilitate that.

Two people have different noses because they have different genes (different instructions for how it should look). Your family has a mole on the left side of their face because that gene continues to be passed down with each generation and instructing the cells in your face to form a mole.

I tried to simplify as much as I could without losing the integrity of the information. I hope this makes sense and is helpful!