So this chromosome is homologous with respect to the second one, which means they carry genes that code for the same exact types of traits. Now, what exactly do we mean by duplication? So let's suppose ves is our gene that is about to break off. So it is exposed to some form of radiation. The bonds are broken, this part detaches. Now, when this part detaches, instead of going back onto this segment chromosome, it moves onto the first chromosome.