So two homologous chromosomes basically are chromosomes that not only have the same type of size, shape and structure, but also carry genes that code for proteins that express the same type of trade. So, to see what we mean, let's take a look at the following homologous pair. So, we have two chromosomes which are said to be homologous with respect to one another. Now, along this chromosome, we have many genes. We can have thousands of different genes. But in this diagram, we only have four different types of gene.