What are the homologous and the heterologous portions of the human sex chromosomes?
Homologous portion is that in which there are genes having alleles in both Y and X sex chromosomes. The homologous portions are situated more in the central part of the sex chromosomes, near the centromere. Heterologous portion is that whose genes do not have correspondent alleles in the other sex chromosome. These genes are located more in the peripheral regions of the arms of the Y and X chromosomes.
