Q.What are holandric genes ?

Holandric genes are genes carried on the Y chromosome's non-homologous region, so they show strict father-to-son inheritance.

The human Y chromosome has a small homologous (pseudoautosomal) region shared with the X chromosome, and a much larger male-specific region unique to the Y, with no counterpart on the X chromosome. Genes located in this Y-specific region are called holandric genes. Since females (XX) never possess a Y chromosome, holandric genes and the traits they determine appear exclusively in males and are transmitted directly from father to all his sons (never through the mother, and never to daughters). The classic textbook example in hu …