So this is basically a homologous chromosome pair. And what that basically means is one of these chromosomes came from the male parent and the other chromosome came from the female parent. And both of these chromosomes carry genes that code for the protein that expresses the same type of traits. Now, notice along each one of these chromosomes, let's suppose along the darker green chromosome, we have two genes. And this red gene is linked to the blue gene in the same exact way that this orange gene is linked to the purple gene. So whenever two or more genes are found on the same chromosome, they are said to be linked to one another.